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OBJECTIVE: To answer the following clinical questions: (1) Is poor postural control associated with increased risk of a lateral ankle sprain? (2) Is postural control adversely affected after acute lateral ankle sprain? (3) Is postural control adversely affected in those with chronic ankle instability? DATA SOURCES: PubMed and CINAHL entries from 1966 through October 2006 were searched using the terms ankle sprain, ankle instability, balance, chronic ankle instability, functional ankle instability, postural control, and postural sway. STUDY SELECTION: Only studies assessing postural control measures in participants on a stable force plate performing the modified Romberg test were included. To be included, a study had to address at least 1 of the 3 clinical questions stated above and provide adequate results for calculation of effect sizes or odds ratios where applicable. DATA EXTRACTION: We calculated odds ratios with 95% confidence intervals for studies assessing postural control as a risk factor for lateral ankle sprains. Effect sizes were estimated with the Cohen d and associated 95% confidence intervals for comparisons of postural control performance between healthy and injured groups, or healthy and injured limbs, respectively. DATA SYNTHESIS: Poor postural control is most likely associated with an increased risk of sustaining an acute ankle sprain. Postural control is impaired after acute lateral ankle sprain, with deficits identified in both the injured and uninjured sides compared with controls. Although chronic ankle instability has been purported to be associated with altered postural control, these impairments have not been detected consistently with the use of traditional instrumented measures. CONCLUSIONS: Instrumented postural control testing on stable force plates is better at identifying deficits that are associated with an increased risk of ankle sprain and that occur after acute ankle sprains than at detecting deficits related to chronic ankle instability. [ABSTRACT FROM AUTHOR]

Objective: To review 16 years of National Collegiate Athletic Association (NCAA) injury surveillance data for men's basketball and identify potential areas for injury prevention initiatives. Background: Collegiate men's basketball is a contact sport in which numerous anatomical structures are susceptible to both acute and overuse injuries. To date, no comprehensive reporting of injury patterns in NCAA men's basketball has been published. Main Results: The overall rate of injury was 9.9 per 1000 athlete-exposures for games and 4.3 per 1000 athlete-exposures for practices. Approximately 60% of all injuries were to the lower extremity, with ankle ligament sprains being the most common injury overall and knee internal derangements being the most common injury causing athletes to miss more than 10 days of participation. A trend of increasing incidence of injuries to the head and face was noted over the 16-year span of the study, which may be related to an observed increase in physical contact in men's basketball over the past 2 decades. Recommendations: These results provide the most comprehensive description of injury patterns in NCAA men's basketball to date. Many of the most common injuries seen in men's basketball, such as ankle ligament sprains and knee internal derangements, may be at least partially preventable with interventions such as taping and bracing and neuromuscular training. However, randomized controlled trials assessing the efficacy of such preventive measures among collegiate men's basketball players are clearly lacking. The increase in head and facial injuries may indicate that officials need to assess the increased tolerance for physical contact in men's basketball seen over the past 2 decades. [ABSTRACT FROM AUTHOR]

Context: Despite the importance of patient's subjective re-ports of function, little research has addressed their use in the athletic population.Objective: To examine the following measurement properties of the Foot and Ankle Disability Index (FADI) and the FADI Sport: (1) intersession reliability during 1- and 6-week intervals, (2) sensitivity to differences between healthy subjects and subjects with chronic ankle instability (CAI), and (3) sensitivity to changes in function in those with CAI after rehabilitation.Design: Test-retest design.Setting: Laboratory setting.Patients or Other Participants: Fifty recreationally active subjects.Main Outcome Measure(s): FADI and FADI Sport. Results: Intraclass correlation coefficients (ICC 2,1) for the FADI and FADI Sport at 1 week were 0.89 and 0.84, respectively, for the involved limbs. Over 6 weeks, the ICC values for the involved limb of subjects who did not complete rehabilitation were 0.93 and 0.92, respectively. For both surveys, scores were significantly less for the involved limbs of subjects with CAI compared with their uninvolved limbs (P < .05). No significant side-to-side differences were noted among the healthy subjects. Scores on both surveys increased significantly after rehabilitation (FADI: P < .05, effect size = 0.52; FADI Sport: P < .05, effect size = 0.71).Conclusions: The FADI and FADI Sport appear to be (1) reliable in detecting functional limitations in subjects with CAI, (2) sensitive to differences between healthy subjects and subjects with CAI, and (3) responsive to improvements in function after rehabilitation in subjects with CAI. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Deficits in static postural control related to chronic ankle instability (CAI) and fatigue have been investigated separately, but little evidence links these factors to performance of dynamic postural control. Our purpose was to investigate the effects of fatigue and CAI on performance measures of a dynamic postural-control task, the Star Excursion Balance Test. DESIGN AND SETTING: For each of the 3 designated reaching directions, 4 separate 5 (condition) x 2 (time) x 2 (side) analyses of variance with a between factor of group (CAI, healthy) were calculated for normalized reach distance and maximal ankle-dorsiflexion, knee-flexion, and hip-flexion angles. All data were collected in the Athletic Training Research Laboratory. SUBJECTS: Thirty subjects (16 healthy, 14 CAI) participated. MEASUREMENTS: All subjects completed 5 testing sessions, during which sagittal-plane kinematics and reaching distances were recorded while they performed 3 reaching directions (anterior, medial, and posterior) of the Star Excursion Balance Test, with the same stance leg before and after different fatiguing conditions. The procedure was repeated for both legs during each session. RESULTS: The involved side of the CAI subjects displayed significantly smaller reach distance values and knee-flexion angles for all 3 reaching directions compared with the uninjured side and the healthy group. The effects of fatigue amplified this trend. CONCLUSIONS: Chronic ankle instability and fatigue disrupted dynamic postural control, most notably by altering control of sagittal-plane joint angles proximal to the ankle. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Elevation and intermittent compression are routinely prescribed after soft tissue injury. Individuals must, however, resume activity in an upright position. The effect of gravity-dependent positioning after elevation and intermittent compression has not been extensively examined. Our purpose was to examine the effects of gravity-dependent positioning after elevation and intermittent compression on the volume of injured ankles. DESIGN AND SETTING: Ankle-injured subjects were randomly assigned to 1 of 2 treatment groups: elevation or elevation and intermittent compression. Each treatment lasted 30 minutes. SUBJECTS: Twelve college students with inversion ankle sprains 2 to 4 days earlier participated. MEASUREMENTS: Measurements of ankle volume were performed before treatment and at 5, 10, 15, 20, 25, 30, 45, and 60 minutes after treatment. RESULTS: Regardless of treatment, ankle volume decreased (by 17.25 +/- 4.05 mL) between the pretreatment measurement and the immediate posttreatment measurement (P <.05). The effects of both treatments, however, lasted less than 5 minutes after the limb was returned to a gravity-dependent position. CONCLUSIONS: These results suggest that elevation or elevation and intermittent compression do not effectively decrease ankle volume for a prolonged period of time in patients with postacute ankle sprains. [ABSTRACT FROM AUTHOR]

Objective: To describe the functional anatomy of the ankle complex as it relates to lateral ankle instability and to describe the pathomechanics and pathophysiology of acute lateral ankle sprains and chronic ankle instability.Data Sources: I searched MEDLINE (1985-2001) and CINAHL (1982-2001) using the key words ankle sprain and ankle instability.Data Synthesis: Lateral ankle sprains are among the most common injuries incurred during sports participation. The ankle functions as a complex with contributions from the talocrural, subtalar, and inferior tibiofibular joints. Each of these joints must be considered in the pathomechanics and pathophysiology of lateral ankle sprains and chronic ankle instability. Lateral ankle sprains typically occur when the rearfoot undergoes excessive supination on an externally rotated lower leg. Recurrent ankle sprain is extremely common; in fact, the most common predis position to suffering a sprain is the history of having suffered a previous ankle sprain. Chronic ankle instability may be due to mechanical instability, functional instability, or most likely, a combination of these 2 phenomena. Mechanical instability may be due to specific insufficiencies such as pathologic laxity, arthrokinematic changes, synovial irritation, or degenerative changes. Functional instability is caused by insufficiencies in proprioception and neuromuscular control.Conclusions/Recommendations: Lateral ankle sprains are often inadequately treated, resulting in frequent recurrence of ankle sprains. Appreciation of the complex anatomy and mechanics of the ankle joint and the pathomechanics and pathophysiology related to acute and chronic ankle instability is integral to the process of effectively evaluating and treating ankle injuries. [ABSTRACT FROM AUTHOR]

Objective: To identify differences in postural control among healthy individuals with different architectural foot types.Design and Setting: We compared postural control during single-leg stance in healthy individuals with cavus, rectus, and planus foot types in our athletic training research laboratory.Subjects: Thirty healthy, young adults (15 men, 15 women; age, 21.9 +/- 2.0 years; mass, 71.6 +/- 16.7 kg; height, 168.4 +/- 13.6 cm) had their feet categorized based on rearfoot and forefoot alignment measures. The right and left feet of a subject could be classified into different categories, and each foot was treated as a subject. There were 19 cavus, 23 rectus, and 18 planus feet.Measurements: Subjects performed three 10-second trials of single-leg stance on each leg with eyes open while standing on a force platform. Dependent measures were center-of-pressure (COP) excursion area and velocity.Results: Subjects with cavus feet used significantly larger COP excursion areas than did subjects with rectus feet. However, COP excursion velocities were not significantly different among foot types.Conclusions: Clinicians and researchers assessing postural control in single-leg stance with measures of COP excursion area must be cognizant of preexisting differences among foot types. If individuals' foot types are not taken into account, the results of clinical and research investigations assessing COP excursion area after injury may be confounded. [ABSTRACT FROM AUTHOR]

Objective: To identify subjects' changes in postural control during single-leg stance in the 4 weeks after acute lateral ankle sprain.Design and Setting: We used a 2 x 2 x 3 (side-by-plane-by-session) within-subjects design with repeated measures on all 3 factors. All tests were performed in a university laboratory.Subjects: Seventeen young adults (9 men, 8 women; age, 21.8 +/- 5.9 years; mass, 74.9 +/- 10.5 kg; height, 176.9 +/- 7.1 cm) who had sustained unilateral acute mild or moderate lateral ankle sprains.Measurements: Measures of center-of-pressure excursion length, root mean square velocity of center-of-pressure excursions (VEL), and range of center-of-pressure excursions (RANGE) were calculated separately in the frontal and sagittal planes during 5-second trials of static single-leg stance.Results: We noted significant side-by-plane-by-session interactions for magnitude of center-of-pressure excursions in a given trial (PSL) (P = .004), VEL (P = .011), and RANGE (P = .009). Both PSL and VEL in the frontal plane were greater in the injured limbs compared with the uninjured limbs on day 1 and during week 2 but not during week 4, whereas sagittal-plane differences existed during all 3 testing sessions. Injuredlimb, frontal-plane RANGE scores were greater than uninjured values at day 1 but not during weeks 2 or 4. No significant differences in sagittal-plane RANGE scores were seen.Conclusions: Postural control was significantly impaired in the injured limbs at day 1 and during week 2 after lateral ankle sprain but not during week 4. Consistent improvement in postural control measures on both injured and uninjured limbs was seen throughout the 4 weeks after ankle sprain. [ABSTRACT FROM AUTHOR]

Objective: The study had 3 objectives: (1) to assess the educational history of doctoral-educated certified athletic trainers (ATCs) who work at academic institutions, (2) to determine the current employment characteristics of doctoral-educated ATCs who work at academic institutions, and (3) to identify which competencies doctoral-educated ATCs feel are important for new doctoral graduates to possess upon graduation.Design and Setting: Multiple sources were used to identify doctoral-educated ATCs who work at academic institutions. These individuals were surveyed to assess their educational histories, current employment characteristics, and opinions on desired competencies for new doctoral graduates. Data were analyzed using descriptive and inferential statistics.Subjects: Surveys were sent to 130 individuals, and the response rate was 89.2% (n = 116).Measurements: Subjects answered questions regarding their educational history and employment characteristics. A 5point Likert scale was used to assess the importance of 22 competencies for new doctoral graduates to possess upon graduation. Comparisons were made between program directors and non-program directors, respondents employed at doctoral-granting institutions and non-doctoral-granting institutions, and doctoral student advisors and non-advisors.Results: Subjects reported several different educational backgrounds, job titles, and job responsibilities. Significant differences in job responsibilities and assessment of desired competencies were found between program directors and non-program directors, employees of doctoral-granting institutions and non-doctoral-granting institutions, and doctoral student advisors and non-advisors.Conclusions: As new doctoral programs are established in athletic training, students should receive training as classroom instructors and program administrators, in addition to learning the skills necessary to perform independent research in athletic training. [ABSTRACT FROM AUTHOR]

Objective: Nonsteroidal anti-inflammatory drugs (NSAIDS) are frequently used to hasten the return of injured athletes to competition after injury. Evidence demonstrates that while NSAIDs may speed recovery after acute soft tissue injuries, long-term healing may be compromised. This review aims to assess the effects of NSAIDs on inflammation and healing associated with acute soft tissue injury. Data Sources: CINAHL (1982 to 1997), SPORT Discus (1977 to 1997), and MEDLINE (1993 to 1997) were searched using the keywords 'NSAIDs,' 'musculoskeletal,' 'acute,' 'sprain,' and 'strain.' Data Synthesis: NSAIDs exhibit anti-inflammatory effects via prostaglandin inhibition, neutrophil migration suppression, and oxygen free-radical inhibition. Retardation of inflammatory processes after acute injury may limit the area of secondary tissue damage but may also retard healing. Animal models have demonstrated short-term benefits with NSAIDs after acute injury, along with long-term adverse effects on tissue structure and function. NSAIDs have exhibited few benefits in the treatment of delayed-onset muscle soreness. Clinical trials of NSAIDs in the treatment of acute soft tissue injuries have shown conflicting results and have been highly criticized. Conclusions/Recommendations: Based on the research literature, the short-term benefits of NSAIDs in the treatment of acute soft tissue injuries must be weighed against the potential long-term adverse effects on tissue healing, structure, and function. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The Protonics brace is a functional resistance brace designed for rehabilitative use in patients with patellofemoral pain syndrome. Our objective was to determine whether the Protonics brace altered quadriceps muscle activity or knee mechanics in healthy subjects. DESIGN AND SETTING: We used a within-subjects design in a laboratory setting. SUBJECTS: Nineteen recreationally active college students (10 females, 9 males; age = 22.6 +/- 2.8 years; height = 172 +/- 9.0 cm, mass = 69.7 +/- 12.5 kg) with no history of patellofemoral pain syndrome. MEASUREMENTS: A standard-length Protonics brace was fit to each subject's leg. Surface electromyography of the vastus medialis obliquus, vastus lateralis, and rectus femoris muscles was recorded during a lateral step-down exercise. Lower extremity kinematics and ground reaction force were assessed during stair descent. Subjects performed both tasks under 4 conditions: no brace and brace with low, medium, and high resistance. Electromyography values were normalized to a maximum voluntary isometric contraction. The brace moment was determined by passive testing in an isokinetic dynamometer. Changes in the subject's muscular knee-extension moment were determined by subtracting the extension moment provided by the brace from the total knee-extension moment calculated from motion and force data using an inverse dynamics approach. RESULTS: Vastus medialis obliquus activity in the brace at the low- and medium-resistance settings was significantly lower than that measured without the brace. Vastus lateralis activity while wearing the brace at medium resistance was significantly less than in the absence of the brace. Regardless of brace setting, vastus medialis obliquus and vastus lateralis activity in the descending phase of the exercise was less than during the ascending phase. A significant interaction was noted between brace setting and phase of the step-down exercise for rectus femoris activity. Significantly less activity was seen in the descending phase than in the ascending phase. Post hoc testing indicated that, in the descending phase, less activity was demonstrated with the brace at the medium and high settings than at the low setting. Muscle activity at the high setting and activity at low resistance were also significantly less than when the brace was not worn in the ascending phase. Knee flexion and extension moment during stair descent were significantly less at the higher resistance settings. CONCLUSIONS: Wearing the Protonics brace at moderate or high resistance during the lateral step-down exercise produced less quadriceps activity compared with not wearing the brace. The knee extensor mechanism was unloaded when the brace was worn during stair descent. These findings indicate that the Protonics brace may unload the quadriceps and therefore decrease the load on the patellofemoral joint. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate surface electromyographic (EMG) activity of the rectus abdominus and external oblique abdominus muscles during pelvic-tilt and abdominal-hollowing exercises performed in different positions. DESIGN AND SETTING: 2 x 3 (exercise by position) within-subjects design with repeated measures on both factors. All testing was performed in a university laboratory. SUBJECTS: Twenty-six healthy, active young adult females. MEASUREMENTS: Surface EMG activity was recorded from the left and right rectus abdominus and external oblique muscles while the 2 exercises (pelvic tilt and abdominal hollowing) were performed in different positions (standard, legs supported, and legs unsupported). The standard position was supine in the crook-lying position, the supported position was with hips and knees flexed to 90 degrees and legs supported on a platform, and the unsupported position was with hips and knees flexed to 90 degrees without external support. Peak EMG activity was normalized to a maximum voluntary isometric contraction for each muscle. RESULTS: For the rectus abdominus, there was an interaction between position and activity. Abdominal hollowing produced significantly less activity than the pelvic tilt in all positions. The difference between the 2 exercises with the legs unsupported was of a greater magnitude than the other 2 positions. For the external obliques, there was significantly lower activity during the abdominal hollowing compared with the pelvic tilting. The greatest muscle activity occurred with the legs-unsupported position during both exercises. CONCLUSIONS: Abdominal-hollowing exercises produced less rectus abdominus and external oblique activity than pelvic-tilting exercises. Abdominal hollowing may be performed with minimal activation of the large global abdominal muscles. [ABSTRACT FROM AUTHOR]

Objective: Chronic instability after lateral ankle sprain has been shown to cause balance deficits during quiet standing. Although static balance assessment in those with ankle instability has been thoroughly examined in the literature, few researchers have studied performance on more dynamic tasks. Our purpose was to determine if the Star Excursion Balance Tests (SEBTs), lower extremity reach tests, can detect deficits in subjects with chronic ankle instability.Design and Setting: We performed all testing in a university athletic training facility. We tested lower extremity reach using the SEBTs, which incorporates single-leg stance with maximal reach of the contralateral leg.Subjects: Twenty subjects with unilateral, chronic ankle instability (age = 19.8 +/- 1.4 years, height = 176.8 +/- 4.5 cm, mass = 82.9 +/- 21.2 kg) and 20 uninjured subjects matched by sex, sport, and position (age = 20.2 +/- 1.4 years, height = 178.7 +/- 4.1 cm, mass = 82.7 +/- 19.9 kg).Measurements: We measured the reach distances in centimeters (cm) and averaged 3 reaches in each of the 8 directions while the subjects stood on each leg for data analysis.Results: The group with chronic ankle instability demonstrated significantly decreased reach while standing on the injured limb compared with the matched limb of the uninjured group (78.6 cm versus 82.8 cm). Additionally, subjects with chronic ankle instability reached significantly less when standing on their injured limbs as compared with their uninjured limbs (78.6 cm versus 81.2 cm).Conclusions: The SEBTs appear to be an effective means for determining reach deficits both between and within subjects with unilateral chronic ankle instability. [ABSTRACT FROM AUTHOR]

Context: Although dozens of individual mechanical and functional insufficiencies have been reported in those with chronic ankle instability (CAI), no authors to date have examined the relationship of the insufficiencies to each other. Therefore, studying both the functional and mechanical insufficiencies in the same experimental design will provide valuable information. Objective: To determine the relationships among the numerous functional and mechanical insufficiencies purported to cause CAI. Design: Descriptive study with a correlational design. Setting: Medical center and research laboratory. Patients or Other Participants: Thirty subjects with unilateral CAI (15 males and 15 females: age = 20.3 ± 1.3 years; height = 172.5 ± 10.7 cm; mass = 72.9 ± 15.8 kg). Main Outcome Measure(s): Twenty-six measures of mechanical insufficiencies (ankle laxity and hypomobility) and functional insufficiencies (subjective level of function, static and dynamic balance, ankle and hip strength) were taken on both limbs of all subjects. Bivariate correlations using Pearson product moment coefficients were calculated between all dependent variables measured in the unstable ankles. The level of significance was set a priori at P <= .05 for all analyses. Results: A number (35) of significant bivariate correlations were identified. Most (32) of these significant relationships were found between functional instability measures (r = .38 to .96). Three significant relationships were noted between measures of functional (balance, strength) and mechanical (laxity, hypomobility) instability (r = .47 to .52). No significant relationships were found between the different mechanical instability measures. Conclusions: Certain measures of functional instability were significantly correlated and may be redundant. Additionally, the significant correlations between measures of functional (balance, strength) and mechanical instability (laxity, hypomobility) demonstrate that the 2 factors are not completely dichotomous and need to be examined together. [ABSTRACT FROM AUTHOR]

Context: An arthrogenic muscle response (AMR) of the soleus and peroneal muscles has been previously demonstrated in individuals with chronic ankle instability (CAI), but the presence of AMR in muscles acting on joints proximal to unstable ankles has not been previously explored. Objective: To determine if AMR is present in the quadriceps and hamstrings muscles of those with and without unilateral CAI. Design: Case control. Setting: University research laboratory. Patients or Other Participants: Twenty subjects with unilateral CAI (12 males, 8 females: age = 19.9 ± 3.7 years; height = 170.3 ± 15.6 cm; mass = 78.0 ± 23.1 kg) and 21 controls (16 males, 5 females: age = 23.2 ± 5.4 years; height = 173.9 ± 12.7 cm; mass = 87.2 ± 24.6 kg) with no previous ankle injuries. Main Outcome Measure(s): The central activation ratio (CAR), a measure of motoneuron pool excitability during maximal voluntary isometric contraction, for the hamstrings and quadriceps muscles was measured in both limbs using the superimposed burst technique. Results: The CAI group demonstrated quadriceps CARs that were significantly larger in their involved limbs (.87 ± .09), as compared with their uninvolved limbs (.84 ± .08), whereas no significant side-to-side difference was seen in the control group (sham involved = .80 ± .11, sham uninvolved = .81 ± .11). When values from both the involved and uninvolved limbs were averaged, the hamstrings CAR was significantly lower for the CAI group (.94 ± .03) than for the control group (.96 ± .03). Conclusions: Arthrogenic inhibition of the hamstrings muscles bilaterally and facilitation of the quadriceps muscle ipsilateral to the involved limb were noted in subjects with unilateral CAI. Motoneuron pool excitability appears to be altered in muscles that act on joints proximal to the ankle in those with unilateral CAI. [ABSTRACT FROM AUTHOR]

Objective: To determine the numbers needed to treat (NNT) and relative risk reduction (RRR) associated with neuromuscular training programs aimed at preventing noncontact anterior cruciate ligament (ACL) injuries in female athletes. Data Sources: We searched PubMed, MEDLINE, SPORT Discus, CINAHL, and Web of Science from 1966 through 2005 using the terms knee, injury, anterior cruciate ligament, ACL, prevention, plyometric, and neuromuscular training. Study Selection: Selected articles were from peer-reviewed journals written in English that described original research studies comparing neuromuscular training programs with control programs to determine the number of noncontact ACL injuries per event exposure or hours of playing time. Five studies met the inclusion criteria and were independently rated by 3 reviewers using the Physiotherapy Evidence Database (PEDro) scale. Consensus PEDro scores ranged from 4 to 7 out of 10. Data Extraction: We used numbers of subjects, ACL injuries, and injury exposure rates to calculate NNT and RRR for each study. The NNT calculations from all studies were based on the number of players across 1 competitive season and were described as NNT benefit or NNT harm. Data Synthesis: All 5 studies demonstrated a prophylactic effect due to the neuromuscular training programs. The pooled NNT estimates showed that 89 individuals (95% confidence interval: 66 to 136) would need to participate in the prophylactic training program to prevent 1 ACL injury over the course of 1 competitive season. Pooled RRR was 70% (95% confidence interval: 54% to 80%) among individuals who participated in the intervention program. One high-quality randomized control trial and 4 medium-quality prospective cohort studies showed mostly consistent findings. Thus, a Strength of Recommendation Taxonomy level of evidence of 1 with a grade B recommendation supports the use of neuromuscular training programs in the prevention of noncontact ACL injuries in female athletes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Taping and bracing are thought to decrease the incidence of ankle sprains; however, few investigators have addressed the effect of preventive measures on the rate of ankle sprains. Our purpose was to examine the effectiveness of ankle taping and bracing in reducing ankle sprains by applying a numbers-needed-to-treat (NNT) analysis to previously published studies. DATA SOURCES: We searched PubMed, CINAHL, SPORT Discus, and PEDro for original research from 1966 to 2002 with key words ankle taping, ankle sprains, injury incidence, prevention, ankle bracing, ankle prophylaxis, andnumbers needed to treat. We eliminated articles that did not address the effects of ankle taping or bracing on ankle injury rates using an experimental design. DATA SYNTHESIS: The search produced 8 articles, of which 3 permitted calculation of NNT, which addresses the clinical usefulness of an intervention by providing estimates of the number of treatments needed to prevent 1 injury occurrence. In a study of collegiate intramural basketball players, the prevention of 1 ankle sprain required the taping of 26 athletes with a history of ankle sprain and 143 without a prior history. In a military academy intramural basketball program, prevention of 1 sprain required bracing of 18 athletes with a history of ankle sprain and 39 athletes with no history. A study of ankle bracing in competitive soccer players produced an NNT of 5 athletes with a history of previous sprain and 57 without a prior injury. A cost- benefit analysis of ankle taping versus bracing revealed taping to be approximately 3 times more expensive than bracing. CONCLUSIONS/RECOMMENDATIONS: Greater benefit is achieved in applying prophylactic ankle taping or bracing to athletes with a history of ankle sprain, compared with those without previous sprains. The generalizability of these results to other physically active populations is unknown. [ABSTRACT FROM AUTHOR]

Objective: To critically assess the literature focused on strength training of the intrinsic foot muscles (IFMs) and resulting improvements in foot function., Data Sources: A search of electronic databases (PubMed, CINAHL, Scopus, and SPORTDiscus) was completed between January 2000 and March 2022., Study Selection: Randomized control trials with an outcome of interest and at least 2 weeks of IFM exercise intervention were included. Outcomes of interest were broadly divided into 5 categories of foot posture (navicular drop and Foot Posture Index), namely: balance, strength, patient-reported outcomes, sensory function, and motor performance. The PEDro scale was used to assess the methodologic quality of the included studies with 2 independent reviewers rating each study. Studies with a PEDro score greater than 4/10 were included., Data Extraction: Data extracted by 2 independent reviewers were design, participant characteristics, inclusion and exclusion criteria, type of intervention, outcomes, and primary results. We performed a random-effects meta-analysis to analyze the difference between intervention and control groups for each outcome when at least 2 studies were available. Standardized mean differences (SMDs) describe effect sizes with 95% CIs (SMD ranges). When the CI crossed zero, the effect was not significant., Data Synthesis: Thirteen studies were included, and IFM exercise interventions were associated with decreasing navicular drop (SMD range = 0.37, 1.83) and Foot Posture Index (SMD range = 1.03, 1.69) and improving balance (SMD range = 0.18, 1.86), strength (SMD range = 0.06, 1.52), and patient-reported outcomes for disability (SMD range = 0.12, 1.00), with pooled effect sizes favoring the IFM intervention over the control. The IFM exercises were not superior (SMD range = -0.15, 0.66) for reducing pain. We could not perform a meta-analysis for sensory function and motor performance, as only 1 study was available for each outcome; however, these results supported the use of IFM strength training., Conclusions: Strength training of the IFMs was helpful for patients in improving foot and ankle outcomes., (© by the National Athletic Trainers’ Association, Inc.)

Context: Return-to-activity (RTA) assessments are commonly administered after anterior cruciate ligament reconstruction (ACLR) to manage the patient's postoperative progressions back to activity. To date, few data are available on the clinical utility of these assessments to predict patient outcomes such as secondary anterior cruciate ligament (ACL) injury once the athlete has returned to activity., Objective: To identify the measures of patient function at 6 months post-ACLR that best predict RTA and second ACL injury at a minimum of 2 years after ACLR., Design: Prospective cohort study., Setting: Laboratory., Patients or Other Participants: A total of 234 patients with primary, unilateral ACLR completed functional assessments at approximately 6 months post-ACLR. Of these, 192 (82.1%) completed follow-up at ≥2 years post-ACLR., Main Outcome Measure(s): The 6-month functional assessments consisted of patient-reported outcomes, isokinetic knee-flexor and -extensor strength, and single-legged hopping. We collected RTA and secondary ACL injury data at ≥2 years after ACLR., Results: Of the patients who were able to RTA (n = 155), 44 (28.4%) had a subsequent ACL injury, 24 (15.5%) to the ipsilateral graft ACL and 20 (12.9%) to the contralateral ACL. A greater proportion of females had a secondary injury to the contralateral ACL (15/24, 62.5%), whereas a greater proportion of males reinjured the ipsilateral ACL graft (15/20, 75.0%; P = .017). Greater knee-extension symmetry at 6 months increased the probability of reinjury (B = 0.016, P = .048). Among patients with RTA at <8 months, every 1% increase in quadriceps strength symmetry at 6 months increased the risk of reinjury by 2.1% (B = 0.021, P = .05). Among patients with RTA at >8 months, every month that RTA was delayed reduced the risk of reinjury by 28.4% (B = -0.284, P = .042). Descriptive statistics of patient function stratified between the early and delayed RTA groups can be found in the Supplemental Table (available online at http://dx.doi.org/10.4085/1062-6050-0407.20.S1)., Conclusions: Patients with more symmetric quadriceps strength at 6 months post-ACLR were more likely to experience another ACL rupture, especially those who returned to sport at <8 months after the index surgery. Clinicians should be cognizant that returning high-functioning patients to activity at <8 months post-ACLR may place them at an increased risk for reinjury., (© by the National Athletic Trainers' Association, Inc.)

Context: Ankle sprains are common occurrences in athletic and general populations. High volumes of ankle sprains elevate the clinical burden on athletic trainers (ATs). The National Athletic Trainers' Association (NATA) published a position statement regarding the treatment and management of ankle sprains, but certain factors might affect an AT's ability to effectively implement the recommendations., Objective: To evaluate ATs' current understanding, perceptions, and difficulties regarding the treatment, management, and long-term effects of ankle sprains., Design: Cross-sectional study., Setting: Online survey instrument., Patients or Other Participants: A total of 796 ATs (years certified = 12.1 ± 9.2) across all athletic training job settings., Main Outcome Measure(s): Participants completed a 38-question survey that addressed their demographic characteristics, as well as their perceptions and knowledge of the epidemiology, treatment, and management of ankle sprains. The survey was also used to document participants' patient education practices and attitudes toward the NATA position statement regarding ankle sprains, along with the challenges of and pressures against implementation. Descriptive statistics, correlations, and analyses of variance were used to analyze the data and evaluate group differences and relationships., Results: Of the participants, 83% demonstrated a moderate understanding of fundamental ankle sprain epidemiology. Group differences regarding patient education were seen by education levels, years certified, and job setting. Overall, 38.1% of ATs were either unsure or unaware of the NATA position statement, but those who were aware rated its usefulness at 3.89 on a scale of 1 to 5, with 1 being not useful at all; 3, neutral; and 5, very useful. On average, 1.9 ± 0.88 challenges to implementing effective treatment practices were documented, and 2.0 ± 0.95 pressures to return athletes to play after ankle sprain were reported., Conclusions: Nearly 40% of the ATs were either unaware or unsure of the current recommendations regarding how patients with ankle sprains are treated, which could affect how care is delivered., (© by the National Athletic Trainers' Association, Inc.)

Context: Sport-related concussion (SRC) is characterized by a pathologic neurometabolic cascade that results in an increased intracranial energy demand and a decreased energy supply. Little is known about the whole-body energy-related effects of SRC., Objective: To examine factors associated with whole-body resting metabolic rate (RMR), total energy expenditure (TEE), energy consumption (EC), and energy balance (EBal) in student-athletes acutely after SRC and healthy matched control individuals., Design: Case-control study., Setting: University research laboratory., Patients or Other Participants: Student-athletes diagnosed with SRC (n = 28, 50% female, age = 18.4 ± 1.8 years, body mass index [BMI] = 24.1 ± 4.1 kg/m2) assessed ≤72 hours postinjury and a matched control group (n = 28, 50% female, age = 19.4 ± 2.9 years, BMI = 24.7 ± 4.78 kg/m2)., Main Outcome Measure(s): Resting metabolic rate was measured via indirect calorimetry. Participants reported their physical activity and dietary intake for 3 days, which we used to estimate TEE and EC, respectively, and to calculate EBal (EC:TEE ratio). Resting metabolic rate, TEE, and EC were normalized to body mass. Group and group-by-sex comparisons were conducted for RMR·kg-1, TEE·kg-1, EC·kg-1, and EBal using independent t tests with the a priori α = .05. Associations of age, sex, concussion history, BMI, and symptom burden with RMR·kg-1 and EBal were explored with linear regression models., Results: Total energy expenditure·kg-1 was lower (P < .01; mean difference ± SD = -5.31 ± 1.41 kcal·kg-1) and EBal was higher (P < .01; 0.28 ± 0.10) in SRC participants than in control participants. Both sexes with SRC had lower TEE·kg-1 than did the control participants (P values ≤ .04); females with SRC had higher EBal than controls (P = .01), but male groups did not differ. Higher RMR·kg-1 was associated with history of concussion (adjusted R2 = .10, β = 0.65). Younger age (β = -0.35), fewer concussions (β = -0.35), lower BMI (β = -0.32), greater symptom duration (β = 1.50), and lower symptom severity (β = -1.59) were associated with higher EBal (adjusted R2 = .54)., Conclusions: Total energy expenditure·kg-1 and EBal appeared to be affected by acute SRC, despite no differences in RMR·kg-1. Sex, concussion history, BMI, and symptom burden were associated with acute energy-related outcomes., (© by the National Athletic Trainers' Association, Inc.)

Context: Athlete monitoring via wearable technology is often used in soccer athletes. Although researchers have tracked global outcomes across soccer seasons, little information exists on athlete loads during individual practice drills. Understanding these demands is important for athletic trainers in making decisions about return to play., Objective: To provide descriptive information on total distance, total player load (PL), total distance per minute, and PL per minute for practice drill structures and game play by player position among female soccer athletes across a competitive season., Design: Retrospective observational study., Setting: National Collegiate Athletic Association Division I university., Patients or Other Participants: A total of 32 female collegiate soccer players (age = 20 ± 1 years, height = 168.75 ± 4.28 cm)., Intervention(s): Athletes wore a single global positioning system and triaxial accelerometer unit during all practices and games in a single soccer season. Individual practice drills were labeled by the team's strength and conditioning coach and binned into physical, technical and tactical skills and large- and small-sided competition drill structures., Main Outcome Measure(s): Descriptive analyses were used to assess the median total distance, total PL, total distance per minute, and PL per minute by drill structure and player position (defender, forward or striker, and midfielder) during practices and games., Results: Large- and small-sided competition drills imposed the greatest percentage of workload across all measures for each position (approximately 20% of total practice), followed by physical drills. When comparing technical and tactical skills drills, we found that technical skills drills required athletes to cover a greater distance (approximately 17% for technical skills and 15% for tactical skills), and tactical skills drills required higher play intensity during practices across all positions (approximately 18% for technical skills and 13% for tactical skills). Defenders had the highest median PL outcomes of all positions during practices., Conclusions: Different practice drill types imposed various levels of demands, which simulated game play, on female soccer athletes. Athletic trainers and other clinicians may use this information in formulating objective return-to-play guidelines for injured collegiate women's soccer players., (© by the National Athletic Trainers' Association, Inc.)

Wearable sensors are capable of capturing foot-strike positioning, which lends insight into landing biomechanics during running. The purpose of our study was to assess the relationship between foot-strike categorization and foot-strike angle during running to validate the sensor-derived foot-strike outcome. Twenty collegiate cross-country athletes (12 females, 8 males) ran at 2 speeds on an instrumented treadmill. RunScribe sensors were used to determine foot-strike categorizations (1-5 = rearfoot, 6-10 = midfoot, 11-16 = forefoot), and foot-strike angles were simultaneously assessed with 3-dimensional motion capture bilaterally. We calculated Pearson r correlation coefficients to compare foot-strike categorizations and angles at initial contact over 800 steps as well as sensor foot-strike identification accuracy. A strong, inverse correlation between foot-strike categorizations and foot-strike angles was present (r = -0.86, P < .001). Overall, the sensors demonstrated 78% accuracy (rearfoot = 72.5%, midfoot = 55.3%, forefoot = 95.4%). These results support the concurrent validity of the sensor-derived foot-strike measures., (© by the National Athletic Trainers' Association, Inc.)

Context: Exercise-related lower leg pain (ERLLP) is common in runners., Objective: To compare biomechanical (kinematic, kinetic, and spatiotemporal) measures obtained from wearable sensors as well as lower extremity alignment, range of motion, and strength during running between runners with and those without ERLLP., Design: Case-control study., Setting: Field and laboratory., Patients or Other Participants: Of 32 young adults who had been running regularly (>10 mi [16 km] per week) for ≥3 months, 16 had ERLLP for ≥2 weeks and 16 were healthy control participants., Main Outcome Measure(s): Both field and laboratory measures were collected at the initial visit. The laboratory measures consisted of alignment (arch height index, foot posture index, navicular drop, tibial torsion, Q-angle, and hip anteversion), range of motion (great toe, ankle, knee, and hip), and strength. Participants then completed a 1.67-mi (2.69-km) run along a predetermined route to calibrate the RunScribe devices. The RunScribe wearable sensors collected kinematic (pronation excursion and maximum pronation velocity), kinetic (impact g and braking g), and spatiotemporal (stride length, step length, contact time, stride pace, and flight ratio) measures. Participants then wore the sensors during at least 3 training runs in the next week., Results: The ERLLP group had a slower stride pace than the healthy group, which was accounted for as a covariate in subsequent analyses. The ERLLP group had a longer contact time during the stance phase of running (mean difference [MD] = 18.00 ± 8.27 milliseconds) and decreased stride length (MD = -0.11 ± 0.05 m) than the control group. For the clinical measures, the ERLLP group demonstrated increased range of motion for great-toe flexion (MD = 13.9 ± 4.6°) and ankle eversion (MD = 6.3 ± 2.7°) and decreased strength for ankle inversion (MD = -0.49 ± 0.23 N/kg), ankle eversion (MD = -0.57 ± 0.27 N/kg), and hip flexion (MD = -0.99 ± 0.39 N/kg)., Conclusions: The ERLLP group exhibited a longer contact time and decreased stride length during running as well as strength deficits at the ankle and hip. Gait retraining and lower extremity strengthening may be warranted as clinical interventions in runners with ERLLP., (© by the National Athletic Trainers' Association, Inc.)

Objective: To evaluate the current literature regarding the utility of global positioning system (GPS)-derived workload metrics in determining musculoskeletal injury risk in team-based field-sport athletes., Data Sources: PubMed entries from January 2009 through May 2019 were searched using terms related to GPS, player workload, injury risk, and team-based field sports., Study Selection: Only studies that used GPS metrics and had injury as the main outcome variable were included., Data Extraction: Total distance, high-speed running, and acute : chronic workload ratios were the most common GPS metrics analyzed, with the most frequent sports being soccer, rugby, and Australian rules football., Data Synthesis: Many distinct workload metrics were associated with increased injury risk in individual studies performed in particular sport circumstances; however, the body of evidence was inconclusive as to whether any specific metrics could consistently predict injury risk across multiple team-based field sports., Conclusions: Our results were inconclusive in determining if any GPS-derived workload metrics were associated with an increased injury risk. This conclusion is due to a myriad of factors, including differences in injury definitions, workload metrics, and statistical analyses across individual studies., (© by the National Athletic Trainers' Association, Inc.)

Context: Patellofemoral pain (PFP) is one of the most prevalent knee conditions observed in women. Current research suggests that individuals with PFP have altered muscle activity, kinematics, and kinetics during functional tasks. However, few authors have examined differences in lower extremity biomechanics in this population during the drop-vertical jump (DVJ)., Objective: To determine how lower extremity electromyography, kinematics, and kinetics during a DVJ and lower extremity isometric strength differed between women with and those without PFP., Design: Cross-sectional study., Setting: Laboratory., Patients or Other Participants: Fifteen healthy women (age = 20.23 ± 1.39 years, height = 169.32 ± 5.38 cm, mass = 67.73 ± 9.57 kg) and 15 women with PFP (age = 22.33 ± 3.49 years, height = 166.42 ± 6.01 cm, mass = 65.67 ± 13.75 kg)., Intervention(s): Three trials of a DVJ., Main Outcome Measure(s): Surface electromyography, kinematics, and kinetics were collected simultaneously during a DVJ. Lower extremity strength was measured isometrically. Independent-samples t tests were performed to assess group differences., Results: Normalized muscle activity in the vastus medialis (healthy group = 120.84 ± 80.73, PFP group = 235.84 ± 152.29), gluteus maximus (healthy group = 43.81 ± 65.63, PFP group = 13.37 ± 13.55), and biceps femoris (healthy group = 36.68 ± 62.71, PFP group = 11.04 ± 8.9) during the landing phase of the DVJ differed between groups. Compared with healthy women, those with PFP completed the DVJ with greater hip internal-rotation moment (0.04 ± 0.28 N/kg versus 0.06 ± 0.14 N/kg, respectively) and had decreased knee-flexion excursion (76.76° ± 7.50° versus PFP = 74.14° ± 19.85°, respectively); they took less time to reach peak trunk flexion (0.19 ± 0.01 seconds versus 0.19 ± 0.02 seconds, respectively) and lateral trunk flexion (0.12 ± 0.07 seconds versus 0.11 ± 0.04 seconds, respectively)., Conclusions: During the DVJ, women with PFP had increased hip internal-rotation moment and decreased knee-flexion excursion with less time to peak trunk flexion and lateral flexion. Muscle activation was increased in the vastus medialis but decreased in the gluteus maximus and biceps femoris. This suggests that altered motor-unit recruitment in the hip and thigh may result in changes in biomechanics during a DVJ that are often associated with an increased risk of injury., (© by the National Athletic Trainers' Association, Inc.)

Context: Increased frontal-plane knee motion during functional tasks, or medial knee displacement, is a predictor of noncontact anterior cruciate ligament injury and patellofemoral pain. Intervention studies that resulted in a reduced risk of knee injury included some form of feedback to address aberrant lower extremity movement patterns. Research on integrating feedback into single-legged tasks and the ability to train 1 task and test another is limited., Objective: To determine if adding real-time visual biofeedback to common lower extremity exercises would improve single-legged landing mechanics in females with medial knee displacement., Design: Cohort study., Setting: University laboratory., Patients or Other Participants: Twenty-four recreationally active females with medial knee displacement were randomized to a visual-biofeedback group (n = 12; age = 19.75 ± 0.87 years, height = 165.32 ± 8.69 cm, mass = 62.41 ± 8.91 kg) or a control group (n = 12; age = 19.75 ± 0.97 years, height = 166.98 ± 6.89 cm, mass = 59.98 ± 6.24 kg)., Intervention(s): Individuals in the feedback group viewed a real-time digital model of their body segments generated by Microsoft Kinect. The skeletal model changed color according to the knee-abduction angle of the test limb during the exercise tasks., Main Outcome Measure(s): Participants completed 3 trials of the single-legged drop vertical jump (SL-DVJ) while triplanar kinematics at the trunk, hip, knee, and ankle were collected via 3-dimensional motion capture. The feedback and control groups completed lower extremity exercises with or without real-time visual biofeedback, respectively. After the intervention, participants completed 3 additional trials of the SL-DVJ., Results: At baseline, the feedback group had 3.83° more ankle eversion than the control group after initial contact. After the intervention, the feedback group exhibited 13.03° more knee flexion during the flight phase of the SL-DVJ and 6.16° less knee abduction after initial contact than the control group. The feedback group also demonstrated a 3.02° decrease in peak knee-abduction excursion compared with the baseline values ( P = .008)., Conclusions: Real-time visual biofeedback immediately improved faulty lower extremity kinematics related to knee-injury risk. Individuals with medial knee displacement adjusted their movement patterns after a single training session and reduced their medial knee motion during a dynamic task.

Context: Impairments in dynamic postural control and gluteal muscle activation have been associated with the development of symptoms related to long-term injury, which are characteristic of chronic ankle instability (CAI). Ultrasound imaging (USI) provides a visual means to explore muscle thickness throughout movement; however, USI functional-activation ratios (FARs) of the gluteal muscles during dynamic balance exercises have not been investigated., Objective: To determine differences in gluteus maximus and gluteus medius FARs using USI, Y-Balance Test (YBT) performance, and lower extremity kinematics in individuals with or without CAI., Design: Cross-sectional study., Setting: University laboratory., Patients or Other Participants: Twenty adults with CAI (10 men, 10 women; age = 21.70 ± 2.32 years, height = 172.74 ± 11.28 cm, mass = 74.26 ± 15.24 kg) and 20 adults without CAI (10 men, 10 women; age = 21.20 ± 2.79 years, height = 173.18 ± 15.16 cm, mass = 70.89 ± 12.18 kg)., Intervention(s): Unilateral static ultrasound images of the gluteal muscles during quiet stance and to the point of maximum YBT reach directions were obtained over 3 trials. Hip, knee, and ankle sagittal-plane kinematics were collected with motion-capture software., Main Outcome Measure(s): Gluteal thickness was normalized to quiet stance to yield FARs for each muscle in each YBT direction. We averaged normalized reach distances and obtained average peak kinematics. Independent t tests, mean differences, and Cohen d effect sizes were calculated to determine group differences for all outcome measures., Results: The CAI group had anterior-reach deficits compared with the control group (mean difference = 4.37%, Cohen d = 0.77, P = .02). The CAI group demonstrated greater anterior gluteus maximus FARs than the control group (mean difference = 0.08, Cohen d = 0.57, P = .05)., Conclusions: The CAI group demonstrated YBT reach deficits and alterations in proximal muscle activation. Increased reliance on the gluteus maximus during dynamic conditions may contribute to distal joint dysfunction in this population.

Context: Individuals with a history of lateral ankle sprains (LASs) have ankle and hip neuromuscular changes compared with those who do not have a history of LAS., Objective: To compare gluteus maximus (GMax), gluteus medius (GMed), and fibularis longus and brevis muscle activation using ultrasound imaging during tabletop exercises and lateral resistance-band walking in individuals with or without a history of LAS or chronic ankle instability (CAI)., Design: Cross-sectional study., Patients or Other Participants: Sixty-seven young adults (27 males, 40 females). Groups were healthy = 16, coper = 17, LAS = 15, CAI = 19. The number of previous sprains was 0 ± 0 in the healthy group, 1.1 ± 0.3 in the coper group, 2.9 ± 2.4 in the LAS group, and 5.3 ± 5.9 in the CAI group., Main Outcome Measure(s): Ultrasound imaging measures of fibularis cross-sectional area (CSA) were collected during nonresisted and resisted ankle eversion. Gluteal muscle thicknesses were imaged during nonresisted and resisted side-lying abduction and during lateral resistance-band walking exercises (lower leg and forefoot band placement). Separate 4 × 2 repeated-measures analyses of variance and post hoc Fisher least significant difference tests were used to assess activation across groups and resistance conditions., Results: All groups demonstrated 3.2% to 4.1% increased fibularis CSA during resisted eversion compared with nonresisted. During side-lying abduction, the LAS and CAI groups displayed increased GMax thickness (6.4% and 7.2%, respectively), and all but the CAI group (-0.4%) increased GMed thickness (5.3%-11.8%) with added resistance in hip abduction. During band walking, the healthy and LAS groups showed increased GMax thickness (4.8% and 8.1%, respectively), and all groups had increased GMed thickness (3.0%-5.8%) in forefoot position compared with the lower leg position. Although the values were not different, copers exhibited the greatest amount of GMed thickness during band-walking activities (copers = 23%-26%, healthy = 17%-23%, LAS = 11%-15%, CAI = 15%-19%)., Conclusions: All groups had increased fibularis CSA with resisted eversion. In side-lying hip abduction, individuals with CAI had greater GMax thickness than GMed thickness. Ultrasound imaging of fibularis CSA and gluteal muscle thickness may be clinically useful in assessing and treating patients with LAS or CAI.

Lateral ankle sprains (LASs) are among the most common injuries incurred during participation in sport and physical activity, and it is estimated that up to 40% of individuals who experience a first-time LAS will develop chronic ankle instability (CAI). Chronic ankle instability is characterized by a patient's being more than 12 months removed from the initial LAS and exhibiting a propensity for recurrent ankle sprains, frequent episodes or perceptions of the ankle giving way, and persistent symptoms such as pain, swelling, limited motion, weakness, and diminished self-reported function. We present an updated model of CAI that aims to synthesize the current understanding of its causes and serves as a framework for the clinical assessment and rehabilitation of patients with LASs or CAI. Our goal was to describe how primary injury to the lateral ankle ligaments from an acute LAS may lead to a collection of interrelated pathomechanical, sensory-perceptual, and motor-behavioral impairments that influence a patient's clinical outcome. With an underpinning of the biopsychosocial model, the concepts of self-organization and perception-action cycles derived from dynamic systems theory and a patient-specific neurosignature, stemming from the Melzack neuromatrix of pain theory, are used to describe these interrelationships.

Context: Patellofemoral pain (PFP) is a chronic condition that presents with lower extremity muscle weakness, decreased flexibility, subjective functional limitations, pain, and decreased physical activity. Patterned electrical neuromuscular stimulation (PENS) has been shown to affect muscle activation and pain after a single treatment, but its use has not been studied in a rehabilitation trial., Objective: To determine the effects of a 4-week impairment-based rehabilitation program using PENS on subjective function, pain, strength, range of motion, and physical activity in individuals with PFP., Design: Randomized controlled trial., Setting: Laboratory., Patients or Other Participants: A total of 21 patients with PFP (5 males, 16 females; age = 23.4 ± 7.6 years, height = 168.0 ± 7.5 cm, mass = 69.0 ± 19.5 kg)., Intervention(s): Participants completed a 4-week supervised rehabilitation program in conjunction with random assignment to receive PENS or sham treatments., Main Outcome Measure(s): Subjective function, pain, strength, range of motion, and physical activity levels were assessed prerehabilitation and postrehabilitation. Subjective function and pain were also assessed at 6 and 12 months postrehabilitation. Repeated-measures analyses of variance and Tukey post hoc testing were conducted with α ≤ .05. We calculated Cohen d effect sizes with 95% confidence intervals., Results: Both groups had statistically and clinically meaningful differences in subjective function, pain, strength, range of motion, and activity level after 4 weeks of impairment-based rehabilitation. Improved subjective function was observed in both groups at 6 and 12 months after the interventions. The PENS group had improvements in current pain for all 3 postrehabilitation times compared with baseline measures., Conclusions: An impairment-based intervention effectively improved subjective function, pain, strength, range of motion, and physical activity levels in individuals with PFP. Participants who received PENS in addition to the rehabilitation program had improved current pain at 6 and 12 months postrehabilitation compared with baseline scores., Trial Registration: ClinicalTrials.gov identifier: NCT02441712.

Context: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of boys' and men's basketball injury data., Objective: To describe the epidemiology of injuries sustained in high school boys' basketball in the 2005-2006 through 2013-2014 academic years and collegiate men's basketball in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance., Design: Descriptive epidemiology study., Setting: Online injury surveillance from basketball teams of high school boys (annual average = 100) and collegiate men (annual average = 55)., Patients or Other Participants: Boys' and men's basketball players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college., Main Outcome Measures: Athletic trainers collected time-loss (≥24 hours) injury and exposure data. Injury rates per 1000 athlete-exposures (AEs) were calculated. Injury rate ratios (IRRs) with 95% confidence intervals (CIs) compared injury rates by school size or division, time in season, event type, and competition level., Results: The High School Reporting Information Online system documented 3056 time-loss injuries during 1 977 480 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 4607 time-loss injuries during 868 631 AEs. The injury rate was higher for college than for high school (5.30 versus 1.55/1000 AE; IRR = 3.43; 95% CI = 3.28, 3.59). The injury rate was higher for competitions than for practices in both high school (IRR = 2.38; 95% CI = 2.22, 2.56) and college (IRR = 2.02; 95% CI = 1.90, 2.14). The most common injuries at both levels were ligament sprains, muscle/tendon strains, and concussions; most injuries affected the ankle, knee, and head/face. Injuries were most often caused by contact with another player or noncontact mechanisms., Conclusions: Injury rates were greater among collegiate players compared with high school players and were greater during competitions than practices at both levels. Distributions of injuries by body part, diagnoses, and mechanisms of injury were similar, suggesting that athletes at both levels may benefit from similar injury-prevention strategies.

Context: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of girls' and women's basketball injury data., Objective: To describe the epidemiology of injuries sustained in high school girls' basketball in the 2005-2006 through 2013-2014 academic years and collegiate women's basketball in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance., Design: Descriptive epidemiology study., Setting: Online injury surveillance from basketball teams in high school girls (annual average = 100) and collegiate women (annual average = 57)., Patients or Other Participants: Girls' and women's basketball players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college., Main Outcome Measure(s): Certified athletic trainers collected time-loss (≥24 hours) injury and exposure data. Injury rates per 1000 athlete-exposures (AEs) were calculated. Injury rate ratios (IRRs) with 95% confidence intervals (CIs) were used to compare injury rates by school size or division, time in season, event type, and competition level., Results: The High School Reporting Information Online system documented 2930 time-loss injuries during 1 609 733 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 3887 time-loss injuries during 783 600 AEs. The injury rate was higher in college than in high school (4.96 versus 1.82/1000 AEs; IRR = 2.73; 95% CI = 2.60, 2.86). The injury rate was higher in competitions than in practices for both high school (IRR = 3.03; 95% CI = 2.82, 3.26) and collegiate (IRR = 1.99; 95% CI = 1.86, 2.12) players. The most common injuries at both levels were ligament sprains, concussions, and muscle/tendon strains; the majority of injuries affected the ankle, knee, and head/face. These injuries were often caused by contact with another player or a noncontact mechanism., Conclusions: Injury rates were higher in collegiate than in high school athletes and in competitions than in practices. Similarities in distributions of injuries by body parts, specific diagnoses, and mechanisms of injury suggest that both levels may benefit from similar injury-prevention strategies.

Context: Relationships between quadriceps function and patient-reported outcomes after anterior cruciate ligament reconstruction (ACLR) are variable and may be confounded by including patients at widely different time points after surgery. Understanding these relationships during the clinically relevant phases of recovery may improve our knowledge of specific factors that influence clinical outcomes., Objective: To identify the relationships between quadriceps function and patient-reported outcomes in patients <2 years (early) and >2 years (late) after ACLR, including those with posttraumatic knee osteoarthritis., Design: Cross-sectional study., Setting: Laboratory., Patients or Other Participants: A total of 72 patients after ACLR: early (n = 34, time from surgery = 9.0 ± 4.3 months), late (n = 30, time from surgery = 70.5 ± 41.6 months), or osteoarthritis (n = 8, time from surgery = 115.9 ± 110.0 months)., Main Outcome Measure(s): The total Knee Injury and Osteoarthritis Outcome Score (KOOS) and Veterans RAND 12-Item Health Survey (VR-12) were used to quantify knee function and global health. Predictors of patient-reported outcomes were involved-limb and symmetry indices of quadriceps function (isokinetic strength [peak torque, total work, average power], maximum voluntary isometric contraction torque, fatigue index, central activation ratio, Hoffmann reflex, active motor threshold) and demographics (age, activity level, pain, kinesiophobia, time since surgery). Multiple linear regression analyses were used to predict KOOS and VR-12 scores in each group., Results: In the early patients, knee-extensor work, active motor threshold symmetry, pain, and activity level explained 67.8% of the variance in the KOOS score ( P < .001); knee-extensor work, activity level, and pain explained 53.0% of the variance in the VR-12 score ( P < .001). In the late patients, age and isokinetic torque symmetry explained 28.9% of the variance in the KOOS score ( P = .004). In the osteoarthritis patients, kinesiophobia and isokinetic torque explained 77.8% of the variance in the KOOS score ( P = .010); activity level explained 86.4% of the variance in the VR-12 score ( P = .001)., Conclusions: Factors of muscle function and demographics that explain patient-reported outcomes were different in patients early and late after ACLR and in those with knee osteoarthritis.

A healthy 19-year-old male college student (height = 177.8 cm, mass = 64.3 kg, body mass index = 20.3 kg/m 2 , Foot Posture Index = -1) participating in a study sustained a grade 2 inversion lateral ankle sprain 3 days after completing patient-reported outcome measures. A treatment protocol including therapeutic exercises and midfoot mobilizations was provided. Patient-reported outcomes assessing physical health, mental health, and foot-ankle function were completed 3 days preinjury and 1, 3, and 12 weeks postinjury. Substantial postinjury changes in function, physical health, and kinesiophobia reflected functional limitations that improved with treatment and time. This level 3 exploration case report provides a rare opportunity to highlight preinjury-to-postinjury changes in patient-reported physical and psychological measures caused by a lateral ankle sprain.

Context:   Injury-prediction models have identified trunk muscle function as an identifiable factor for future injury. A history of low back pain (HxLBP) may also place athletes at increased risk for future low back pain. Reduced muscle thickness of the lumbar multifidus (LM) and transversus abdominis (TrA) has been reported among populations with clinical low back pain via ultrasound imaging in multiple positions. However, the roles of the LM and TrA in a more functional cohort and for injury prediction are still unknown., Objectives:   To (1) assess the reliability of LM and TrA ultrasound measures, (2) compare changes in muscle thickness across positions between persons reporting or not reporting HxLBP, and (3) determine the ability to distinguish between groups., Design:   Cross-sectional study., Setting:   Research laboratory., Patients or Other Participants:   Participants were 34 people who did not report HxLBP (age = 22 ± 7 years, body mass index = 23.7 ± 2.7) and 25 people who reported HxLBP (age = 25 ± 10 years, body mass index = 24.0 ± 3.2)., Main Outcome Measure(s):   Muscle thickness and changes in muscle thickness of the LM and TrA as shown on ultrasound imaging., Results:   Intraclass correlation coefficients ranged from 0.641 to 0.943 for all thickness measures and from 0 to 0.693 for all averaged thickness modulations bilaterally. Participants who reported HxLBP had voluntarily reduced TrA thickness modulations compared with those not reporting HxLBP ( P = .03), and the testing position influenced TrA thickness modulations ( P < .01). No differences were observed for LM thickness modulations between groups or positions ( P > .05). A tabletop cutoff value of 1.32 had a sensitivity of 0.640 and a specificity of 0.706, whereas a seated cutoff value of 1.18 had a sensitivity of 0.600 and a specificity of 0.647., Conclusions:   In participants reporting HxLBP, TrA thickness modulations were lower and both tabletop and seated thickness modulations were able to distinguish reported HxLBP status. These findings suggest that TrA muscle function may be altered by HxLBP.

Context:   Central and peripheral neural adaptations have been identified after anterior cruciate ligament (ACL) injury and reconstruction (ACLR) and are hypothesized to contribute to posttraumatic muscle dysfunction. Limited evidence exists about the temporal nature of neuromuscular adaptations during early and late-term phases of recovery after ACLR, and no researchers have studied patients with posttraumatic osteoarthritis., Objective:   To compare quadriceps neuromuscular function less than 2 years ( early) and more than 2 years ( late) after ACLR, including in patients who experienced posttraumatic knee osteoarthritis., Design:   Cross-sectional study., Setting:   Laboratory., Patients or Other Participants:   A total of 72 patients after ACLR, consisting of 34 early (9.0 ± 4.3 months postsurgery), 30 late (70.5 ± 41.6 months postsurgery), and 8 with osteoarthritis (115.9 ± 110.0 months postsurgery), and 30 healthy control volunteers., Main Outcome Measure(s):   Quadriceps function was measured bilaterally during a single visit to determine normalized Hoffmann reflex (H : M ratio), knee-extension maximal voluntary isometric contraction torque (Nm/kg), central activation ratio (%), fatigue index (% decline), and active motor threshold (%). Comparisons were made using 2-way analyses of variance to identify the effect of limb and group on each outcome measure. We calculated Cohen d effect sizes to assess the magnitude of difference between ACLR and matched control limbs for each group., Results:   Compared with healthy control limbs, involved-limb maximal voluntary isometric contraction was lower among all patients after ACLR ( P < .001, Cohen d values = -1.00 to -1.75). The central activation ratio ( P < .001, Cohen d = -1.74) and fatigue index ( P = .003, Cohen d = -0.95) were lower among patients only early after ACLR. The active motor threshold was higher among all patients after ACLR ( P < .001, Cohen d values = -0.42 to -1.56)., Conclusions:   Neuromuscular impairments were present in patients early and late after ACLR, regardless of osteoarthritis status. Quadriceps strength and corticospinal excitability were impaired at each time point compared with values in healthy control individuals, suggesting the need to address cortical function early after ACLR.

Context:   Chronic ankle instability (CAI) is a condition characterized by range-of-motion, neuromuscular, and postural-control deficits and subjective disability, reinjury, and posttraumatic osteoarthritis. Differences have been reported in kinematics, kinetics, surface electromyography (EMG), and ground reaction forces during functional tasks performed by those with CAI. These measures are often collected independently, and the research on collecting measures simultaneously during a movement task is limited., Objective:   To assess the kinematics and kinetics of the lower extremity, vertical ground reaction force (vGRF), and EMG of 4 shank muscles during a drop-vertical-jump (DVJ) task., Design:   Controlled laboratory study., Setting:   Motion-capture laboratory., Patients or Other Participants:   Forty-seven young, active adults in either the CAI (n = 24) or control (n = 23) group., Intervention(s):   Three-dimensional motion capture was performed using an electromagnetic motion-capture system. Lower extremity kinematics, frontal- and sagittal-plane kinetics, vGRF, and EMG of the shank musculature were collected while participants performed 10 DVJs., Main Outcome Measure(s):   Means and 90% confidence intervals were calculated for all measures from 100 milliseconds before to 200 milliseconds after force-plate contact., Results:   Patients with CAI had greater inversion from 107 to 200 milliseconds postcontact (difference = 4.01° ± 2.55°), smaller plantar-flexion kinematics from 11 to 71 milliseconds postcontact (difference = 5.33° ± 2.02°), greater ankle sagittal-plane kinetics from 11 to 77 milliseconds postcontact (difference = 0.17 ± 0.09 Nm/kg) and from 107 to 200 milliseconds postcontact (difference = 0.23 ± 0.03 Nm/kg), and smaller knee sagittal-plane kinematics from 95 to 200 milliseconds postcontact (difference = 8.23° ± 0.97°) than control participants after landing. The patients with CAI had greater vGRF from 94 to 98 milliseconds postcontact (difference = 0.83 ± 0.03 N/kg) and peroneal activity from 17 to 128 milliseconds postcontact (difference = 10.56 ± 4.52 N/kg) than the control participants., Conclusions:   Patients with CAI presented with differences in their landing strategies that may be related to continued instability. Kinematic and kinetic changes after ground contact and greater vGRF may be related to a faulty landing strategy. The DVJ task should be considered for rehabilitation protocols in these individuals.

Context:   The fourth edition of the Preparticipation Physical Evaluation recommends functional testing for the musculoskeletal portion of the examination; however, normative data across sex and grade level are limited. Establishing normative data can provide clinicians reference points with which to compare their patients, potentially aiding in the development of future injury-risk assessments and injury-mitigation programs., Objective:   To establish normative functional performance and limb-symmetry data for high school-aged male and female athletes in the United States., Design:   Cross-sectional study., Setting:   Athletic training facilities and gymnasiums across the United States., Patients or Other Participants:   A total of 3951 male and female athletes who participated on high school-sponsored basketball, football, lacrosse, or soccer teams enrolled in this nationwide study., Main Outcome Measure(s):   Functional performance testing consisted of 3 evaluations. Ankle-joint range of motion, balance, and lower extremity muscular power and landing control were assessed via the weight-bearing ankle-dorsiflexion-lunge, single-legged anterior-reach, and anterior single-legged hop-for-distance (SLHOP) tests, respectively. We used 2-way analyses of variance and χ 2 analyses to examine the effects of sex and grade level on ankle-dorsiflexion-lunge, single-legged anterior-reach, and SLHOP test performance and symmetry., Results:   The SLHOP performance differed between sexes (males = 187.8% ± 33.1% of limb length, females = 157.5% ± 27.8% of limb length; t = 30.3, P < .001). A Cohen d value of 0.97 indicated a large effect of sex on SLHOP performance. We observed differences for SLHOP and ankle-dorsiflexion-lunge performance among grade levels, but these differences were not clinically meaningful., Conclusions:   We demonstrated differences in normative data for lower extremity functional performance during preparticipation physical evaluations across sex and grade levels. The results of this study will allow clinicians to compare sex- and grade-specific functional performances and implement approaches for preventing musculoskeletal injuries in high school-aged athletes.

Context: Musculoskeletal injury-prediction methods vary and may have limitations that affect the accuracy of results and clinical meaningfulness., Background: Research examining injury risk factors is meaningful, but attempting to extrapolate injury risk from studies that do not prospectively assess injury occurrence may limit clinical applications. Injury incidence is a vital outcome measure, which allows for the appropriate interpretation of injury-prediction analyses; a lack of injury-incidence data may decrease the accuracy and increase the uncertainty of injury-risk estimates. Extrapolating results that predict an injury risk factor to predicting actual injuries may lead to inappropriate clinical decision-making models., Conclusions: Improved understanding of the limitations of injury-prediction methods, specifically those that do not prospectively assess injuries, will allow clinicians to better assess the clinical meaningfulness of the results.

Context: Individuals with chronic ankle instability (CAI) present with decreased modulation of the Hoffmann reflex (H-reflex) from a simple to a more challenging task. The neural alteration is associated with impaired postural control, but the relationship has not been investigated in individuals with CAI., Objective: To determine differences in H-reflex modulation and postural control between individuals with or without CAI and to identify if they are correlated in individuals with CAI., Design: Descriptive laboratory study., Setting: Laboratory., Patients or Other Participants: A total of 15 volunteers with CAI (9 males, 6 females; age = 22.6 ± 5.8 years, height = 174.7 ± 8.1 cm, mass = 74.9 ± 12.8 kg) and 15 healthy sex-matched volunteers serving as controls (9 males, 6 females; age = 23.8 ± 5.8 years, height = 171.9 ± 9.9 cm, mass = 68.9 ± 15.5 kg) participated., Intervention(s): Maximum H-reflex (H max ) and motor wave (M max ) from the soleus and fibularis longus were recorded while participants lay prone and then stood in unipedal stance. We assessed postural tasks of unipedal stance with participants' eyes closed for 10 seconds using a forceplate., Main Outcome Measure(s): We normalized H max to M max to obtain H max  : M max ratios for the 2 positions. For each muscle, H-reflex modulation was quantified using the percentage change scores in H max  : M max ratios calculated from prone position to unipedal stance. Center-of-pressure data were used to compute 4 time-to-boundary variables. Separate independent-samples t tests were performed to determine group differences. Pearson product moment correlation coefficients were calculated between the modulation and balance measures in the CAI group., Results: The CAI group presented less H-reflex modulation in the soleus (t 26 = -3.77, P = .001) and fibularis longus (t 25 = -2.59, P = .02). The mean of the time-to-boundary minima in the anteroposterior direction was lower in the CAI group (t 28 = -2.06, P = .048). We observed a correlation (r = 0.578, P = .049) between the fibular longus modulation and mean of time-to-boundary minima in the anteroposterior direction., Conclusions: The strong relationship indicated that, as H-reflex amplitude in unipedal stance was less down modulated, unipedal postural control was more impaired. Given the deficits in H-reflex modulation and postural control in the CAI group, the relationship may provide insights into the neurophysiologic mechanism of postural instability.

Context: The intrinsic foot muscles maintain the medial longitudinal arch and aid in force distribution and postural control during gait. Impaired intrinsic foot-muscle function has been linked to various foot conditions. Several rehabilitative exercises have been proposed to improve it; however, literature that identifies which individual muscles are activated during specific intrinsic foot-muscle exercises is lacking., Objective: To describe changes in activation of the intrinsic plantar foot muscles after 4 exercises as measured with T2 magnetic resonance imaging (MRI)., Design: Descriptive laboratory study., Setting: Research laboratory., Patients or Other Participants: Eight healthy National Collegiate Athletic Association Division I collegiate cross-country and track athletes (5 men and 3 women: age = 20 ± 0.93 years, height = 180.98 ± 10.84 cm, mass = 70.91 ± 7.82 kg)., Intervention(s): Participants underwent T2 MRI before and after each exercise. They completed 1 set of 40 repetitions of each exercise (short-foot exercise, toes spread out, first-toe extension, second- to fifth-toes extension)., Main Outcome Measure(s): Percentage increases in muscle activation of the abductor hallucis, flexor digitorum brevis, abductor digiti minimi, quadratus plantae, flexor digiti minimi, adductor hallucis oblique, flexor hallucis brevis, and interossei and lumbricals (analyzed together) after each exercise were assessed using T2 MRI., Results: All muscles showed increased activation after all exercises. The mean percentage increase in activation ranged from 16.7% to 34.9% for the short-foot exercise, 17.3% to 35.2% for toes spread out, 13.1% to 18.1% for first-toe extension, and 8.9% to 22.5% for second- to fifth-toes extension. All increases in activation had associated 95% confidence intervals that did not cross zero., Conclusions: Each of the 4 exercises was associated with increased activation in all of the plantar intrinsic foot muscles evaluated. These results may have clinical implications for the prescription of specific exercises to target individual intrinsic foot muscles.