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Purpose: Pandemic-induced lockdowns disrupted sport training and competition. We aimed to identify the impact on the mental health of high-level athletes and clarify whether the effects differ for team-based and individual athletes. Methods: This cross-sectional survey, stratified by sex and sport type, collected demographic data and mental health measurements from 274 Brazilian high-performance athletes (142 from team sports and 132 from individual sports) involved with the Brazilian Olympic Committee program for the Tokyo Olympics 2021. Depression, disturbed sleep, and anxiety were assessed by the 9-Item Patient Health Questionnaire, 7-Item Insomnia Severity Index, and 7-Item Generalized Anxiety Disorder scale respectively. Responses were analyzed dichotomously according to published threshold values, characterizing the relative frequency distribution of prevalence (PCRS) or non-prevalence of clinically relevant symptoms (NPCRS). Results: Out of all participants, 47 [17.1%], Z(274) = 15.38, p =.001, 32 [11.7%], Z(274) = 17.94, p =.001, and 49 [17.9%], Z(274) = 15.04, p =.001 had PCRS of anxiety, insomnia, and depression, respectively. There were no significant differences in the PCRS among genders. Compared with individual sport athletes, team sport athletes were more likely to report PCRS of insomnia (12 [37.5%] vs 20 [62.5%], Z(274) = −2.00, p =.046), and depression (18 [36.7%] vs 31 [63.3%], Z(274) = −2.63, p =.009) but not for anxiety. Conclusion: Athletes reported high levels of mental health problems during the lockdown. Team sport athletes reported worse symptoms of insomnia and depression than individual sport athletes, possibly due to the impact of unaccustomed social isolation and lack of social team activity. Therefore, it becomes relevant to consider psychological support to team sport athletes who for some reason, such as a pandemic, enduring crisis even injury rehabilitation needs to be isolated. [ABSTRACT FROM AUTHOR]

Background: Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated. Objective: To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains. Design: Systematic review. Data Sources: Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar. Eligibility Criteria for Selecting Studies: Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series. Results: 9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain. Conclusion: 233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures. Prospero Registration: CRD42020156763. [ABSTRACT FROM AUTHOR]

Background: Patellar tendinopathy (PT) is common and debilitating for jumping athletes. Intriguingly, despite its high prevalence and many research studies, a causal explanation for PT presence remains elusive. Objective: Our objective was to investigate whether landing biomechanics among jumping athletes are associated with PT and can predict onset. Methods: We conducted a systematic review with evidence gap map and meta-analysis. We searched three databases from inception to May 2021 for observational studies or trials evaluating landing biomechanics in jumping athletes with PT (JPTs). We assessed quality with a modified Downs and Black checklist, risk of bias with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, and evidence levels with van Tulder's criteria and provided an evidence gap map. Results: One prospective cohort (moderate quality), one cross-sectional cohort (moderate quality), and 14 case–control (four high-, seven moderate-, and three low-quality) studies, including 104 JPTs, 14 with previous PT, 45 with asymptomatic patellar tendon abnormality (PTA), and 190 controls were retained. All studies had a high risk of bias. Meta-analysis showed an association between lower ankle dorsiflexion and the presence of tendinopathy during drop and spike landings, and JPTs had reduced knee joint power and work during volleyball approach or drop landings (moderate evidence). Limited evidence suggested that JPTs had lower patellar tendon loads during drop landings. Strong or moderate evidence showed no relation between PT and sagittal plane peak knee and hip angles or range of motion; hip, knee, or ankle angles at initial contact (IC); knee angular velocities, peak trunk kinematics, or trunk angles at IC; sagittal plane hip, knee, or ankle moments; and peak vertical ground reaction force (vGRF) and vGRF impulse. Identified gaps were that no study simultaneously investigated athletes with previous PT, current PT, and PTA, and studies of joint angular velocities at IC, ankle and hip angular velocities after touchdown, leg stiffness, loading rate of forces, and muscle activation are lacking. Conclusion: Despite the voluminous literature, large number of participants, multitude of investigated parameters, and consistent research focus on landing biomechanics, only a few associations can be identified, such as reduced ankle dorsiflexion–plantarflexion range. Further, the quality of the existing literature is inadequate to draw strong conclusions, with only four high-quality papers being found. We were unable to determine biomechanical factors that predicted PT onset, as longitudinal/prospective studies enabling causal inference are absent. The identified gaps indicate useful areas in which to explore causal relationships to inform intervention development. Therefore, high-quality prospective studies are essential to definitively determine whether landing biomechanics play a part in the development, recurrence, or management of PT and represent a potential therapeutic or preventive target alongside non-biomechanical factors. [ABSTRACT FROM AUTHOR]

Lifestyle interventions involving exercise training offset the adverse effects of androgen deprivation therapy in men with prostate cancer. Yet provision of integrated exercise pathways in cancer care is sparse. This study assessed the feasibility and acceptability of an embedded supervised exercise training intervention into standard prostate cancer care in a single-arm, multicentre prospective cohort study. Feasibility included recruitment, retention, adherence, fidelity and safety. Acceptability of behaviourally informed healthcare and exercise professional training was assessed qualitatively. Despite the imposition of lockdown for the COVID-19 pandemic, referral rates into and adherence to, the intervention was high. Of the 45 men eligible for participation, 79% (n = 36) received the intervention and 47% (n = 21) completed the intervention before a government mandated national lockdown was enforced in the United Kingdom. Patients completed a mean of 27 min of aerobic exercise per session (SD = 3.48), at 77% heart rate maximum (92% of target dose), and 3 sets of 10 reps of 3 resistance exercises twice weekly for 12 weeks, without serious adverse event. The intervention was delivered by 26 healthcare professionals and 16 exercise trainers with moderate to high fidelity, and the intervention was deemed highly acceptable to patients. The impact of societal changes due to the pandemic on the delivery of this face-to-face intervention remain uncertain but positive impacts of embedding exercise provision into prostate cancer care warrant long-term investigation. [ABSTRACT FROM AUTHOR]

Background: Neuromuscular deficits are common following knee injuries and may contribute to early-onset post-traumatic osteoarthritis, likely mediated through quadriceps dysfunction. Objective: To identify how peri-articular neuromuscular function changes over time after knee injury and surgery. Design: Systematic review with meta-analyses. Data Sources: PubMed, Web of Science, Embase, Scopus, CENTRAL (Trials). Eligibility Criteria for Selecting Studies: Moderate and high-quality studies comparing neuromuscular function of muscles crossing the knee joint between a knee-injured population (ligamentous, meniscal, osteochondral lesions) and healthy controls. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and other torque related outcomes. Results: A total of 46 studies of anterior cruciate ligament (ACL) and five of meniscal injury were included. For ACL injury, strength and voluntary activation deficits were evident (moderate to strong evidence). Cortical excitability was not affected at < 6 months (moderate evidence) but decreased at 24+ months (moderate evidence). Spinal-reflex excitability did not change at < 6 months (moderate evidence) but increased at 24+ months (strong evidence). We also found deficits in torque variability, rate of torque development, and electromechanical delay (very limited to moderate evidence). For meniscus injury, strength deficits were evident only in the short-term. No studies reported gastrocnemius, soleus or popliteus muscle outcomes for either injury. No studies were found for other ligamentous or chondral injuries. Conclusions: Neuromuscular deficits persist for years post-injury/surgery, though the majority of evidence is from ACL injured populations. Muscle strength deficits are accompanied by neural alterations and changes in control and timing of muscle force, but more studies are needed to fill the evidence gaps we have identified. Better characterisation and therapeutic strategies addressing these deficits could improve rehabilitation outcomes, and potentially prevent PTOA. Trial Registration Number: PROSPERO CRD42019141850. [ABSTRACT FROM AUTHOR]

Background: Sports-related groin pain (SRGP) is a common entity in rotational sports such as football, rugby and hockey, accounting for 12-18 % of injuries each year, with high recurrence rates and often prolonged time away from sport. Objective: This systematic review synthesises movement and muscle function findings to better understand deficits and guide rehabilitation. Study Selection: Prospective and retrospective cross-sectional studies investigating muscle strength, flexibility, cross-sectional area, electromyographic activation onset and magnitude in patients with SRGP were included. Search Methods: Four databases (MEDLINE, Web of Knowledge, EBSCOhost and EMBASE) were searched in June 2014. Studies were critiqued using a modified version of the Downs and Black Quality Index, and a meta-analysis was performed. Results: Seventeen studies (14 high quality, 3 low quality; 8 prospective and 9 retrospective) were identified. Prospective findings: moderate evidence indicated decreased hip abduction flexibility as a risk factor for SRGP. Limited or very limited evidence suggested that decreased hip adduction strength during isokinetic testing at ~119°/s was a risk factor for SRGP, but no associations were found at ~30°/s or ~210°/s, or with peak torque angle. Decreased hip abductor strength in angular velocity in ~30°/s but not in ~119°/s and ~210°/s was found as a risk factor for SRGP. No relationships were found with hip internal or external rotation range of movement, nor isokinetic knee extension strength. Decreased isokinetic knee flexion strength also was a potential risk factor for SRGP, at a speed ~60°/s. Retrospective findings: there was strong evidence of decreased hip adductor muscle strength during a squeeze test at 45°, and decreased total hip external rotation range of movement (sum of both legs) being associated with SRGP. There was strong evidence of no relationship to abductor muscle strength nor unilateral hip internal and external rotation range of movement. Moderate evidence suggested that increased abduction flexibility and no change in total hip internal rotation range of movement (sum of both legs) were retrospectively associated with SRGP. Limited or very limited evidence (significant findings only) indicated decreased hip adductor muscle strength during 0° and 30° squeeze tests and during an eccentric hip adduction test, but a decrease in the isometric adductors-to-abductors strength ratio at speed 120°/s; decreased abductors-to-adductors activation ratio in the early phase in the moving leg as well as in all three phases in the weight-bearing leg during standing hip flexion; and increased hip flexors strength during isokinetic and decrease in transversus abdominis muscle resting thickness associated with SRGP. Conclusions: There were a number of significant movement and muscle function associations observed in athletes both prior to and following the onset of SRGP. The strength of findings was hampered by the lack of consistent terminology and diagnostic criteria, with there being clear guides for future research. Nonetheless, these findings should be considered in rehabilitation and prevention planning. [ABSTRACT FROM AUTHOR]

Background: Patellofemoral pain (PFP) is highly prevalent within both sporting and recreationally active populations. Multiple treatment approaches have been advocated for the management of PFP, attempting to address both intrinsic and extrinsic factors thought to contribute to the development and persistence of pain. A number of predictors of treatment success have been proposed, and evaluated, for directing intervention choice. Objective: Our aim was to systematically review the literature that identifies outcome predictors of specific conservative interventions in the management of PFP, including quality of the current evidence, to guide clinical practice and future studies investigating outcome predictors within this population. Data Sources: The AMED, CINAHL, EMBASE, MEDLINE and Web of Science databases were searched from inception to April 2013. Study Selection: Randomized controlled trials (RCTs) and cohort studies. Study Appraisal and Synthesis Methods: Following initial searching, all potential papers were assessed by two independent reviewers for inclusion using a checklist developed from the inclusion criteria. Cited, and citing, references were also searched in Google Scholar, but unpublished work was not sought. Methodological quality was assessed using a previously designed quality assessment scale. Definitions for levels of evidence were guided by recommendations made by van Tulder et al. Results: Fifteen low-quality (LQ) cohort studies were included. No RCTs were found. This systematic review identified the evaluation of 205 conservative management outcome predictor variables. Of this large number of variables that have been assessed, 19 (9 %) were found to significantly predict a successful outcome. Where two or more outcome predictors and success determinants were consistent between studies, data were pooled. Within these studies, the low number of participants per output variable, and absence of controls, is likely to compromise the validity of the predictor's accuracy. Very limited evidence identified higher functional index questionnaire scores (mean 0.82, 95 % confidence interval [CI] 0.18-1.46), greater forefoot valgus (mean 0.67, 95 % CI 0.05-1.28) and greater rearfoot eversion magnitude peak (mean −0.93, 95 % CI −1.84 to −0.01) to significantly predict improved outcomes with orthoses interventions. Shorter symptom duration ( p = 0.019), lower frequency of pain ( p = 0.012), younger age, faster vastus medialis oblique reflex response time ( p = 0.026), negative patella apprehension, absence of chondromalacia patella, tibial tubercle deviation of <14.6 mm and greater total quadriceps cross-sectional area on magnetic resonance imaging ( p = 0.01), and reduced eccentric average quadriceps peak torque ( p = 0.015) significantly predicted exercise intervention success following multivariate statistical analysis. Limited evidence identified increased Q-angle (mean 0.38, 95 % CI 0.05-0.72) and very limited evidence identified greater usual pain (mean 0.43, 95 % CI 0.01-0.85) to predict taping intervention success. Conclusions: This systematic review provides a comprehensive summary of current derivation level studies identifying indicators of prediction for conservative PFP management. The overall strength of evidence was low. With appropriate caution, clinicians should consider taping for those with greater usual pain, orthoses for older individuals and exercise for younger individuals, and orthoses intervention for patients with greater forefoot valgus and rearfoot eversion magnitude peak. RCTs with evaluation of outcome prediction as a primary aim are clearly warranted to provide clinicians with robust evidence and facilitate evidence-informed, tailored intervention to this heterogeneous patient population. [ABSTRACT FROM AUTHOR]

Purpose: Pressure algometry (PA) may provide an objective and standardised tool in assessing palpation pain over the tibia. The purpose of this study was to analyse the intra-rater repeatability of PA and to determine whether tibial tenderness in healthy runners differ from runners with medial tibial stress syndrome (MTSS). Methods: Pressure algometry was performed on 20 asymptomatic runners (40 legs) and 9 MTSS patients (14 symptomatic legs) at standardised locations along the medial border of the tibia. Intra-rater reliability was assessed in 10 randomly selected asymptomatic runners through repeated measurements 2 weeks later. Results: Intra-rater reliability was moderate to excellent (ICC 0.53-0.90) in asymptomatic runners. Pain pressure threshold (PPT) was significantly reduced at 2/9-5/9 of the distance from the medial malleolus to the medial tibial condyle ( p = 0.002-0.022). There was evidence of a statistically significant association between both height and weight, and PPT from the 3/9 ( r = 0.416, p = 0.008) to 7/9 ( r = 0.334, p = 0.035) and 3/9 ( r = 0.448, p = 0.004) to 6/9 ( r = 0.337, p = 0.034) area, respectively. In both MTSS patients and healthy runners, there was evidence of lower PPT in females compared to males ( p = 0.0001-0.049) and a negative association between age and PPT ( p = 0.001-0.033). MTSS patients had significantly lower PPT at the 3/9 site ( p = 0.048) compared to asymptomatic runners. Conclusion: Pain pressure threshold algometry can be incorporated into MTSS clinical assessment to objectively assess pain and monitor progress. The presence of reduced medial tibial PPT in asymptomatic runners suggests that clinicians may not need to await resolution of medial tibia tenderness before allowing return to sport in MTSS patients. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Background: Distance running continues to experience increased participation in the Western world, although it is associated with high injury rates. Barefoot running has been increasingly proposed as a means to prevent overuse injury due to various biomechanical differences, including reduced joint loading rates and altered kinematics and muscle activity patterns compared to shod running. Objective: The aim of this review was to systematically evaluate biomechanical differences between running barefoot and shod, including the quality of available evidence, in order to provide guidance on the phenomenon of barefoot running to the running and sports medicine communities. Data sources: A comprehensive search of MEDLINE, Web of Knowledge and EMBASE from inception to January 2013 was performed. Study selection: Trials evaluating injury-free recreational or competitive adults who participate in long-distance running (≥5 km), where a comparison of barefoot and shod running lower-limb kinetics, kinematics and/or electromyography were included. Studies examining sprinting and studies of single-subject design were excluded. Study appraisal and synthesis methods: Following initial searching, two reviewers identified a shortlist of relevant studies based on title and abstract, with the full text of these studies being tested against the inclusion criteria. References of included studies were examined and citation tracking was performed in Web of Knowledge. Two independent reviewers evaluated the methodological quality of each included study using a modified version of the Downs and Black quality index. Results of the quality assessment were used to identify high- and low-quality studies, data pooling was completed where possible and levels of evidence were determined based on the van Tulder criteria. Results: Eighteen studies were identified, all of low methodological quality. Effect size (ES) calculation was possible for 12 studies. Pooled results indicate moderate evidence that barefoot running is associated with reduced peak ground reaction force (GRF), increased foot and ankle plantarflexion and increased knee flexion at ground contact compared with running in a neutral shoe. Limited evidence indicates barefoot running is associated with reduced impact GRF, reduced peak knee flexion and varus joint moments, and a higher stride frequency compared to a neutral shoe. Very limited to limited evidence also indicates power absorption at the knee is decreased while being increased at the ankle whilst barefoot running. Additionally, the effects of barefoot running on loading rate appear dependent on strike pattern adopted, with a forefoot strike pattern found to reduce loading rate, whilst a rearfoot strike pattern increases loading rate when running barefoot compared to shod. Limitations: Key methodological weaknesses that must be addressed in future research were identified. Of particular note were absence of investigator blinding, infrequent intervention randomisation, small sample sizes and lack of evaluation following habituation. Two studies could not be retrieved because of publication in a non-English-language journal. Of particular note is that the validity of the body of work is compromised by the lack of evaluation after habituation, or re-training, of previously shod rearfoot-striking runners to barefoot forefoot-striking running styles. Conclusions: There has been a great deal of publicity for barefoot running, and many claims made about its effects and risks. Despite a large amount of biomechanical data available for meta-analysis, clear guidance for clinical practice is limited because of the low methodological quality of the associated studies. Preliminary biomechanical differences identified suggest barefoot running may be associated with positive biomechanical changes in regards to injury prevention, although this may be dependent on strike pattern adopted. Further research employing more robust methodology, which addresses weaknesses highlighted in this review, is needed to confirm current preliminary evidence. Additionally, prospective research would have higher validity were the biomechanical effects of habituating to barefoot running fully examined alongside an evaluation of prevention of repetitive use injury. [ABSTRACT FROM AUTHOR]

Abstract: Background: Arterial stiffness is an independent risk factor for cardiovascular disease. There has been no previous research comparing the acute changes to arterial stiffness following aerobic exercise in different groups of athletes. The aim of this study was to compare the acute effect of aerobic exercise on arterial stiffness in resistance-trained (RT) athletes, endurance-trained (ET) athletes and sedentary controls. Methods: Central and peripheral pulse wave velocity (PWV) were measured before and at 3, 15 and 30 min intervals post-exercise in RT athletes (n = 18), ET athletes (n = 19) and sedentary controls (n = 15). PWV was measured using Doppler flow velocimeters and derived from the ‘foot-to-foot’ transit times. Blood pressure and heart rate recordings preceded all PWV measurements. Results: Resting PWV did not differ significantly between groups. In the endurance and control group, central PWV increased at 3 min post-exercise (from 7.7 ± 2.2 to 10.6 ± 4.2 m/s; P = 0.02 and from 7.4 ± 2.2 to 9.1 ± 3.1 m/s; P = 0.01 respectively), followed by a decline to baseline within 15 min of exercise cessation. Central PWV fell at 30 min post-exercise (P = 0.08) in the resistance group, although this was a non-significant reduction. Peripheral PWV did not change significantly from respective baseline values in any group. Conclusion: The ET and control group exhibited differences in their central arterial response to exercise compared to the RT group, although peripheral arterial response was similar between the groups. Higher intensity and/or prolonged exercise is likely to be required for more pronounced differences. [Copyright &y& Elsevier]

Background: Clinicians manage midportion Achilles tendinopathy (AT) using complex clinical reasoning underpinned by a rapidly developing evidence base. Objectives: The objectives of the study were to develop an inclusive, accessible review of the literature in combination with an account of expert therapists' related clinical reasoning to guide clinical practice and future research. Methods: Searches of the electronic databases, PubMed, ISI Web of Science, PEDro, CINAHL, EMBASE, and Google Scholar were conducted for all papers published from inception to November 2011. Reference lists and citing articles were searched for further relevant articles. Inclusion required studies to evaluate the effectiveness of any conservative intervention for midportion AT. Exclusion criteria included in vitro, animal and cadaver studies and tendinopathies in other locations (e.g. patella, supraspinatus). From a total of 3497 identified in the initial search, 47 studies fulfilled the inclusion criteria. Studies were scored according to the PEDro scale, with a score of ≥8/10 considered of excellent quality, 5-7/10 good, and ≤4/ 10 poor. The strength of evidence supporting each treatment modality was then rated as `strong', `moderate', `limited', `conflicting' or `no evidence' according to the number and quality of articles supporting that modality. Additionally, semi-structured interviews were conducted with physiotherapists to explore clinical reasoning related to the use of various interventions with and without an evidence base, and their perceptions of available evidence. Results: Evidence was strong for eccentric loading exercises and extra- corporeal shockwave therapy; moderate for splinting/bracing, active rest, low-level laser therapy and concentric exercises (i.e. inferior to eccentric exercise). In-shoe foot orthoses and therapeutic ultrasound had limited evidence. There was conflicting evidence for topical glycerin trinitrate. Taping techniques and soft-tissue mobilization were not yet examined but featured in case studies and in the interview data. Framework analysis of interview transcripts yielded multiple themes relating to physiotherapists' clinical reasoning and perceptions of the evidence, including the difficulty in causing pain while treating the condition and the need to vary research protocols for specific client groups - such as those with the metabolic syndrome as a likely etiological factor. Physiotherapists were commonly applying the modality with the strongest evidence base, eccentric loading exercises. Barriers to research being translated into practice identified included the lack of consistency of outcome measures, excessive stringency of some authoritative reviews and difficulty in accessing primary research reports. The broad inclusion criteria meant some lower quality studies were included in this review. However, this was deliberate to ensure that all available research evidence for the management of midportion AT, and all studies were evaluated using the PEDro scale to compensate for the lack of stringent inclusion criteria. Conclusion: Graded evidence combined with qualitative analysis of clinical reasoning produced a novel and clinically applicable guide to conservative management of midportion AT. This guide wilt be useful to novice clinicians learning how to manage this treatment-resistant condition and to expert clinicians reviewing their evidence-based practice and developing their clinical reasoning. Important areas requiring future research were identified including the effectiveness of orthoses, the effectiveness of manual therapy, etiological factors, optimal application of loading related to stage of presentation and how to optimize protocols for different types of patients such as the older patient with the metabolic syndrome as opposed to the athletically active. [ABSTRACT FROM AUTHOR]

Open kinetic chain (OKC) knee extensor resistance training has lost favour in rehabilitation of patients with knee ACLD due to concerns that this exercise is harmful to the remaining portion of the ACL and its secondary stabilizers, and will be less effective in improving function. In this randomized, single-blind clinical trial, closed and OKC knee extensor training were compared for their effects on knee laxity and function in patients with ACLD knees. Sixty-four patients with a diagnosis of knee ACLD (49 M, 15 F; mean age=30 years) were measured for knee laxity, using a ligament arthrometer, and function with the Hughston Clinic knee self-assessment questionnaire and maximal effort single leg jump testing. Between the above tests and identical tests carried out 6 weeks later, subjects trained using either open or closed kinetic chain resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week for 6 weeks. The groups exhibited no statistically significant differences (p<0.083) in outcome. These results indicate that knee extensor OKC training, as used in this study, can be safely applied to patients with knee ACL deficiency, and shows no superiority to CKC training. [ABSTRACT FROM AUTHOR]

Open kinetic chain (OKC) knee extensor resistance training has lost favour in ACLR rehabilitation due to concerns that this exercise is harmful to the graft and will be less effective in improving function. In this randomized, single-blind clinical trial OKC and closed kinetic chain (CKC) knee extensor training were compared for their effects on knee laxity and function in the middle period of ACLR rehabilitation. The study subjects were 49 patients recovering from ACLR surgery (37 M, 12 F; mean age=33 years). Tests were carried out at 8 and 14 weeks after ACLR with knee laxity measured using a ligament arthrometer and function with the Hughston Clinic knee self-assessment questionnaire and single leg, maximal effort jump testing (post-test only). Between tests, subjects trained using either OKC or CKC resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week. No statistically significant (one-way ANOVA, p>0.05) differences were found between the treatment groups in knee laxity or leg function. OKC and CKC knee extensor training in the middle period of rehabilitation after ACLR surgery do not differ in their effects on knee laxity or leg function. Exercise dosages are described in this study and further research is required to assess whether the findings in this study are dosage specific. [ABSTRACT FROM AUTHOR]