Search

BACKGROUD: The control of hip and ankle joint movement is important for patients with dynamic knee valgus (DKV), but few studies have used non-elastic taping (NET) to adjust alignment of the hip and ankle joints during overhead squat (OHS) simultaneously in patients with DKV. OBJECTIVE: We investigated changes in lower extremity joint kinematics and dynamic balance after the application of NET to the hip and ankle joints during OHS. METHODS: A total of 30 DKV patients participated in this study. We determined the kinematics of the hip, knee, and ankle joints, and scores on the lower quarter Y-balance test (YBT-LQ) during OHS under three conditions (non-taping, NET on hip and ankle, and sham taping). RESULTS: Hip internal rotation, knee valgus, and the ankle dorsiflexion angle were significantly lower with NET than with non- or sham taping. The hip flexion angle and scores on the YBT-LQ were significantly greater with NET than with non- or sham taping. CONCLUSIONS: The application of NET while performing a OHS is a useful method for correcting lower extremity alignment in patients with DKV, however, application of NET on the ankle should be considered. [ABSTRACT FROM AUTHOR]

BACKGROUND: Many studies have reported that exercise increases physical flexibility; however, no study has verified whether patients perceive an increase in physical flexibility after exercise. OBJECTIVE: This study investigates the correlations between increased duration of exercise and the self-rated flexibility (SRF) and those between the SRF and quantitative flexibility. Variations in the SRF between males and females were also investigated. METHODS: The SRF of the hip (S-Hip) and ankle (S-Ankle) were rated by participants who completed a questionnaire. The range of motion of the hip (M-Hip) and ankle (M-Ankle) were measured using the straight leg raise test and dorsiflexion, respectively. RESULTS: No significant correlation between exercise duration and S-Hip and S-Ankle were identified. S-Hip and S-Ankle (p < 0.001) and S-Hip and M-Hip (p < 0.001) were significantly correlated, though S-Ankle and M-Ankle were not (p = 0.660). The exercise duration, S-Hip, and S-Ankle were not significantly different between males and females. CONCLUSIONS: Given the significant correlation between hip flexibility and SRF and no gender effect, SRF may serve as a useful clinical indicator. [ABSTRACT FROM AUTHOR]

BACKGROUND: Various interventions have been recommended to increase ankle dorsiflexion range of motion (DFROM); however, few studies have investigated the long-term effects of applying gastrocnemius stretching with talus-stabilizing taping (GSTST). OBJECTIVE: To compare the effects of gastrocnemius stretching (GS) and GSTST on DFROM and balance in subjects with limited DFROM. METHODS: Twenty-six subjects with limited DFROM were randomly allocated to either the GS group (n = 13) or GSTST group (n = 13) for 6 weeks. Maximum DFROM before heel-off during gait, passive DFROM, posterior talar glide, flexibility of the gastrocnemius, and the lower-quarter Y-balance test (YBT-LQ) were assessed pre-intervention and post-intervention. Two-way repeated-measures analysis of variance was used to compare the changes in variables. RESULTS: The GSTST group had greater maximum DFROM before heel-off, passive DFROM, and posterior talar glide than the GS group. Gastrocnemius flexibility and YBT-LQ scores increased significantly post-intervention in both groups; however, there was no significant difference between the groups. CONCLUSIONS: GSTST is recommend for improving ankle DFROM and balance in subjects with limited DFROM. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reactive performance is an important component of rhythmic gymnastics. So far, it is unclear whether additional plyometric training in female gymnasts shows an increase in performance. OBJECTIVE: The aim of the study was to examine the effect of additional plyometric training in rhythmic gymnastics on the reactive jumping performance and strength of the lower leg muscles. METHODS: Fifteen rhythmic gymnasts (age: 12.3 ± 2.6 years, height: 1.47 ± 0.12 m, body weight: 37.3 ± 9.3 kg, BMI: 16.7 ± 2.1 kg*m - 2 ; competition level: national and international championships, Tanner stages I–III) participated in the study. The athletes were assigned to an experimental (EG) and a control group (CG). The EG performed plyometric exercises three times per week in addition to the regular training. Before and after six weeks of training the reactive jump performance, the work of dorsi flexors and plantar flexors performed during isokinetic plantarflexion, as well as the performance in two sport-specific tests were measured. RESULTS: In contrast to the CG, in the EG the jump height (pre: 24.8; post: 27.25 cm; p < 0.05) and the reactive-strength-index (pre: 1.01; post: 1.19; p < 0.01) increased significantly. The EG achieved significant improvements in the counter movement jump test (pre: 27.0 cm; post: 31.5 cm; p < 0.01) and in the sport specific double rope jump test (jumps per minute, pre: 18.0; post: 23.0; p < 0.01). Furthermore, a significant increase in work performed during plantarflexion was found in the EG for the right leg (pre: 24.9 J; post: 29.7 J; p < 0.01) and a tendency to increase for the left leg (pre: 26.4 J; post: 37.7 J; p = 0.05). CONCLUSION: Both reactive strength and dynamic force can be efficiently increased by plyometric training. It may be recommended to include plyometric exercises in the training regime of rhythmic gymnasts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p < 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p < 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p < 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Local vibration (LV) used as part of the warm-up can stimulate a specific body part and muscle group, potentially increasing muscle flexibility and performance. However, the effect of its combination with static stretching (SS) has not been thoroughly examined. OBJECTIVE: To elucidate the acute effectiveness of combining LV and SS (V + S) on the ROM of ankle dorsiflexion, squat jump, counter-movement jump (CMJ) and the dynamic postural stability index (DPSI). METHODS: Fifteen healthy men who were regularly involved in recreational sports participated in this study. Static Stretching, V + S, and non-stretching condition (control) were assigned randomly and the intervention period for each condition was five minutes. RESULTS: The dorsiflexion improved significantly in SS and V + S compared to the control. The CMJ height decreased significantly following SS compared to V + S and control. CONCLUSIONS: This study suggests that V + S improves ankle dorsiflexion ROM without compromising jump performance. Local vibration device could be an effective element in warming up but further research is warranted. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sit-to-stand test is very often used as measure of lower limb strength in elderly adults. However, the recent findings indicate that performance in this test is also influenced by other factors. OBJECTIVE: To investigate the association between anthropometric, lower limb strength, and balance variables with the 5-repetition sit-to-stand test (5RSTST) in elderly women. METHODS: Forty physically active elderly women ⩾ 60 years underwent the 5RSTST and anthropometric, balance, and lower limb strength assessment. Anthropometric measurements included height and weight. Balance was quantified in the bipedal upright stance on the basis of the centre of pressure sway in the anteroposterior (CoP AP) and mediolateral (CoP ML) direction. Bilateral concentric strength of the ankle plantarflexors and dorsiflexors, knee flexors and extensors, and hip extensors was measured. RESULTS: The time to complete the 5RSTST was significantly but mildly associated with height (r = 0.356, p = 0.024), ankle dorsiflexor strength (r = - 0.413, p = 0.017), knee flexor strength (r = - 0377, p = 0.030), knee extensor strength (r = - 0.411, p = 0.017), hip flexor strength (r = - 0.359, p = 0.040) on dominant limb, and balance in both directions (AP, r = 0.651, p < 0.001; ML, r = 0.647, p < 0.001). Balance control in AP direction and knee extensor strength on dominant limb were the only factors that contributed independently to 5RSTST, accounting for 55% of the variance. Balance control in AP direction alone explained 41% of the variance in 5RSTST. CONCLUSIONS: Balance control in AP seems to be the most important factor explaining the 5RSTST performance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tissue flossing is a new method aiming to improving range of motion (ROM), pain, and enhancing injury prevention. Tissue flossing involves passive twisting and active movement with the muscle or joint tightly wrapped with a floss band. However, evidence is lacking regarding the effects of flossing. OBJECTIVE: To compare the effects of flossing and static stretching (SS) on gastrocnemius (GC) function. METHODS: Twenty healthy young men received three interventions (Flossing, SS, Rest). The experimental intervention involved flossing using a floss band (Sanctband COMPRE Floss™ Blueberry), and the control intervention involved SS for 5 minutes. The following outcomes were measured before (pre) and after (post) each intervention: dorsiflexion ROM, passive moment, fascicle length, muscle hardness, maximal isometric voluntary plantar flexion contraction, rate of force development (RFD), and muscle activity. RESULTS: The pre-post changes in RFD 0-50 and RFD 0-100 ms were significantly higher with Flossing compared to SS. The pre-post changes in dorsiflexion ROM was significantly higher with Flossing compared to Rest. CONCLUSIONS: Flossing on GC improved RFD 0-50 and RFD 0-100 ms with an increase in dorsiflexion ROM unlike SS. Research is warranted whether flossing before exercise may be more beneficial than SS for injury prevention and physical performance enhancement. [ABSTRACT FROM AUTHOR]

BACKGROUND: There have been multiple studies focusing on the relationship between ankle muscle torque and fatigue with different body positions but have found conflicting results. OBJECTIVE: We investigated the effect of body position on maximum voluntary isometric contractions (MVIC) of ankle plantarflexors (PF) and dorsiflexors (DF) in the pre and post-fatigued conditions in healthy adults. METHODS: Twenty-five participants ran on a treadmill until volitional exhaustion by performing the Bruce protocol. The participants then performed three MVICs for both PF and DF before and after volitional exhaustion. RESULTS: Peak torques of PF (p < 0.01) and DF (p <0.01) in the pre-fatigue condition were greater than in the post-fatigue condition regardless of the body position. Peak torques of PF (p < 0.01) and DF (p = 0.03) in the seated position were greater than in the supine position regardless of time. Variances of peak torque differences were not significantly different between the pre and post-fatigue conditions for the seated and supine positions (p = 0.09). CONCLUSIONS: The results of this study suggest that the body position affects ankle PF and DF torques but does not influence the magnitude of PF and DF strength declines elicited by a fatiguing protocol. Therefore, to obtain the most reliable MVIC measurements, the body position during MVICs should be consistent. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exercises that stretch the gastrocnemius (GCM) lead to greater ankle dorsiflexion (DF). GCM stretching combined with talar self-stabilisation has been reported to increase ankle DF range of motion (ROM). However, excessive subtalar and midtarsal pronation during GCM stretching may compensate for reduced ankle DF. Thus, this study examined the combined immediate effect of stretching GCM and stabilising talus and subtalar supination on limited ankle DF. OBJECTIVE: This study aimed to investigate the immediate effect of GCM stretching alone, GCM stretching with talar selfstabilisation and GCM stretching with talar self-stabilisation and subtalar supination on ankle kinematics in subjects with limited ankle DF. METHODS: Fifteen subjects with limited ankle DF were recruited. The subjects performed the three abovementioned methods. RESULTS: GCM stretching with talar self-stabilisation and subtalar supination significantly increased open-chain and closedankle DF ROM compared with GCM stretching alone. Moreover, GCM stretching combined with talar self-stabilisation and subtalar supination significantly increased open-chain ankle DF ROM with knee straight compared with pre-intervention (P < 0.017). CONCLUSIONS: The preferred method to increase ankle DF ROM is GCM stretching combined with talar self-stabilisation and subtalar supination. [ABSTRACT FROM AUTHOR]

BACKGROUND: Effects of whole-body-vibration (WBV) training have been claimed to depend on individual characteristics and vibration frequency; however, there have not been any studies focusing on effects of different WBV frequencies on flexibility, jump performance, and dynamic balance ability in the same group. METHODS: Twenty healthy men participants were randomly assigned to three conditions [0 Hz, 25 Hz, 40 Hz] prior to the study. They stood barefoot on the non-dominant leg and performed WBV of 5 sets × 30 seconds. In pre- and post-WBV in each condition, the participants measured ankle dorsiflexion angle; single leg squat jump (SLSJ) height; and dynamic postural stability index (DPSI), anterior-posterior stability index (APSI), medial-lateral stability index (MLSI), and vertical stability index (VSI). RESULTS: Ankle dorsiflexion angle at 25 and 40 Hz and SLSJ height at 25 Hz significantly increased after WBV (p < 0.01). DPSI and APSI at 25 Hz and 40 Hz significantly decreased, except VSI, which was significant only at 25 Hz (p < 0.05). CONCLUSIONS: The acute effects of exposure to WBV on flexibility, jump performance, and dynamic balance ability differ by the selected vibration frequencies. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is no information about the reliability of a comprehensive way to assess muscle tone that contains the different dimensions that define or could influence it in the ankle plantar flexors. OBJECTIVE: To evaluate the relative and absolute test-retest intra-day and inter-day reliability of a comprehensive protocol for the assessment of muscle tone responsiveness of the ankle plantar flexors. METHODS: Twenty healthy volunteers completed the study. It was performed a methodological study protocol (SPIRITT). Assessments included passive resistive torque-to-ankle dorsiflexion at slow (10 ∘ /s) and fast (180 ∘ /s) velocities, muscle extensibility measured as passive dorsiflexion range of motion, maximum isometric force and surface electromyography. Three measures were taken with a one-hour (intra-day reliability) and a one-week (inter-day reliability) rest interval between sessions. Inter-session reliability was examined through typical percentage error (CV TE), percentage of change in the mean and intraclass correlation coefficients (ICC). RESULTS: Passive resistive-torque using isokinetic showed better reliability (CV TE from 7.1% to 18.3% and ICC: 0.64 to 0.94) than variables obtained with electromyography (CV TE : 36.5% to 72.5%; ICC: 0.56 to 0.69) and intra-day reliability showed better results than inter-day reliability. Extensibility test and maximal isometric force showed a very good intra-day and inter-day reliability (ICC from 0.82 to 0.97). CONCLUSION: The comprehensive protocol of muscle tone assessment showed very good reliability. The protocol established provides a reliable tool to assess and characterise muscle status and the effect of therapeutic interventions. [ABSTRACT FROM AUTHOR]

BACKGROUND: There have been conflicting findings regarding the relationship between ankle muscle fatigue and a fatiguing run due to different selections of running protocol. Bruce protocol is strongly established as a maximum graded exercise test for volitional fatigue. OBJECTIVE: To determine if volitional exhaustion utilizing the Bruce protocol would result in localized ankle plantarflexor (PF) and dorsiflexor (DF) fatigue. METHODS: Twenty-three healthy individuals participated. Participants ran on a treadmill until they reached volitional exhaustion during performance of the Bruce protocol. Before and after volitional exhaustion, participants performed 3 maximum voluntary isometric contractions for both PF and DF with electromyography (EMG) assessing activation of the tibialis anterior, peroneus longus, and medial gastrocnemius muscles. RESULTS: Volitional exhaustion resulted in ankle PF fatigue (moment: p < 0.001), ankle DF fatigue (moment: p < 0.001), median frequency (p = 0.021) and mean amplitude (p < 0.001) of the tibialis anterior (TA). CONCLUSIONS: That the general fatigue induced by the Bruce protocol caused ankle PF and DF fatigue. Identifying and understanding the neuromuscular responses to volitional fatigue following running are helpful in not only improving the comfort and enjoyment of physical activities, but also in enhancing training and safety of injuries associated of these activities. [ABSTRACT FROM AUTHOR]

BACKGROUND: The high variability in muscle performance, especially in muscle strength, typical of people with multiple sclerosis (PwMS) implies that in order for strength variations to be clinically interpretable, the extent of variability should be properly quantified. OBJECTIVE: To establish the responsiveness of maximal isokinetic strength measurements obtained from the ankle dorsiflexors of PwMS and of a cohort of matched healthy controls. METHODS: Twenty PwMS and 20 healthy controls participated in this study. All subjects underwent a dedicated familiarization session and then three isokinetic testing sessions (Test 1; 1-day retest; 1-week retest) in which the peak moment (PM) and maximal work (MW) were recorded in the more affected side. RESULTS: PwMS proved significantly weaker than controls ( p < 0.00005). The test-retest consistency of the measurements proved high for both groups (all intraclass correlation coefficients > 0.9). Importantly, the smallest real difference (SRD) scores ranged 11.4–19.8% for PwMS and 9.2–14.4% for controls. CONCLUSIONS: The responsiveness of the strength and work findings in this cohort indicates that isokinetic measurements of dorsiflexion performance in PwMS may effectively be employed for detecting the efficiency of an intervention in spite of the fluctuating nature of this disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: After ankle sprains, therapists may use proprioceptive training programs to manage residual symptoms and reduce the risk for recurrent injuries. However, evidence on program effectiveness is limited. OBJECTIVE: To investigate effectiveness of balance and proprioceptive neuromuscular facilitation (PNF) programs in individuals with sprain. METHODS: Participants were recruited from a rehabilitation center and were randomly allocated to a balance or PNF group. Both groups received 10 training sessions, within a six-week period. Ankle position sense, isokinetic strength and EMG activity were assessed by a blinded investigator at baseline, at the end of training and eight weeks after training. Recurrent injuries were recorded 12 months after training. RESULTS: Twenty participants provided follow-up data. Eight weeks after training, significant (p < 0.017) gains were found in most strength measures for both groups, apart from dorsiflexion strength (p > 0.05). For the balance group, there were no recurrent injuries and for the PNF group the recurrent injury rate was 20%. Eight weeks after training, the balance group significantly (p < 0.017) improved plantar flexion position sense and EMG activity of peroneus longus muscle and the PNF group significantly (p < 0.017) improved EMG activity of tibialis anterior muscle. CONCLUSIONS: For individuals with sprain, balance and PNF programs are recommended for ankle strengthening. They may also be effective in reducing the risk for recurrent injuries. [ABSTRACT FROM AUTHOR]

BACKGROUND: There continues to be ongoing debates among researchers as to the positive or negative effects of short-term wearing of high heeled shoes (HH) on ankle muscles. OBJECTIVE: To investigate ankle functions among people wearing low-, mid-, and high-heel shoes as well as the effects different heel measurement heights have among the groups. METHODS: Seventy-eight female college students who habitually wore heeled shoes at various heights from 2.71 to 10.15 cm for approximately one academic year (40.10 ± 10.13 weeks) took part in this study. Participants were grouped according to their heel heights: low-, mid- and high-heels. Body composition was measured as well as the isokinetic strength of ankle muscles at three different heights: 0 cm, 5 cm and 10 cm, relating to the distance between the standard foot attachment and the foot supporting plate. The isokinetic strength (in Nm) of the ankle dorsiflexor (DF), plantarflexor (PF), evertor (EV), and invertor (IV) muscle groups was recorded for the dominant and non-dominant sides. The total strength of ankle muscles (TSAM), which is the sum of the peak moment of all 4 muscle groups was calculated for both sides for all groups. RESULTS: The wearing of HH shoes significantly enhanced the isokinetic strength of all ankle muscles when measured at a height of 0 cm, and some ankle muscles (PF and EV) when measured at a height of 5 cm. However, these effects decreased as the measurement height increased for DF, PF, EV and IV (P <0.05) for both sides. Moreover, there were no significant differences between high- and low-heels groups at the measurement height of 10 cm. The TSAM for both sides also showed no significant differences between groups when measuring at 10 cm. CONCLUSIONS:Wearing of HH shoes for one year may contribute to enhancing the isokinetic strength of ankle muscles when wearing flat or mid-heeled shoes. However, the positive effects that were measured in lower height conditions (0 cm and 5 cm) disappeared when measured using higher heights, indicating that wearing HH shoes yields no benefits for building ankle muscle strength. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lower-extremity strength and neuromuscular parameters that are more affected with age and in individuals more prone tofall still needs to be identified in healthy physically active adults. OBJECTIVE: To investigate the ability of joint torque and muscle activity parameters to differentiate between physically active women, young, older non-fallers and older fallers; and their correlation with the number of falls in older women. METHODS:Measures were taken from concentric contractions during isokinetic sagittal plane movements at 90°/s and 120°/s. EMG from the rectus femoris, vastus lateralis, biceps femoris, lateral gastrocnemius and tibialis anterior were recorded. RESULTS: Overall young women were stronger, more powerful and presented lower muscle activation than older women fallers and non-fallers (all p < 0.04). Older women fallers had lower knee flexion and extension peak torque (p < 0.033) and power (p < 0.045), lower ankle dorsiflexion power (p = 0.04) and higher rectus femoris activation (p = 0.033) at 90°/s than older women non-fallers; and all these variables were correlated with the number of falls (r = 0.32-0.49; p < 0.05). CONCLUSIONS: These findings may be useful for a better understanding of biomechanical risk factors for falls and for exercise-based fall prevention programs development. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the reproducibility of measurements derived from a plantar flexion and dorsiflexion isokinetic test protocol. Recreationally active men (n=8) and women (n=18) were seated in 30° of trunk flexion and full knee extension (0° of knee flexion) and performed three concentric and eccentric dorsiflexion and plantar flexion movements at the speeds of 30°/s and 120°/s on two different occasions. Peak torque (PT) and average torque (AT) measurements were obtained and compared across the two sessions. Intra-class correlation coefficient (ICC's) values indicated acceptable reproducibility for the concentric and eccentric PT and AT values of dorsiflexion (range from 0.77–0.93) and plantar flexion (range from 0.78–0.95). The corresponding Standard Error of Measurement (SEM) values indicated a good level of measurement precision. These findings suggest that this isokinetic test protocol involving an extended knee position for isolating PF and DF ankle motions produces reliable measurements. This test protocol offers a viable alternative to traditional test positions used to assess isokinetic strength in the ankle joint. [ABSTRACT FROM AUTHOR]