Running Habits and Injury Frequency Following COVID-19 Restrictions in Adolescent Long-Distance Runners.

PURPOSE: A decline in youth running was observed at the start of the COVID-19 pandemic. We investigated whether the resumption of organized running after social distancing restrictions changed running habits or injury frequency in adolescent runners. METHODS: Adolescents (age = 16.1 [2.1] y) who participated in long-distance running activities completed an online survey in the Spring and Fall of 2020. Participants self-reported average weekly running habits and whether they sustained an injury during the Fall 2020 season. Poisson regression models and 1-way analysis of variance compared running habits while Fisher exact test compared differences in frequencies of injuries during Fall 2020 among season statuses (full, delayed, and canceled). RESULTS: All runners, regardless of season status, increased weekly distance during Fall 2020. Only runners with a full Fall 2020 season ran more times per week and more high-intensity runs per week compared with their Spring 2020 running habits. There were no differences in running volume or running-related injury frequency among Fall 2020 season statuses. CONCLUSIONS: There were no significant differences in running-related injury (RRI) frequency among runners, regardless of season status, following the resumption of cross-country. Health care providers may need to prepare for runners to increase running volume and intensity following the resumption of organized team activities.

Clinical phenotype and musculoskeletal characteristics of patients with aggrecan deficiency.

Aggrecan is a proteoglycan within the physeal and articular cartilage. Aggrecan deficiency, due to heterozygous mutations in the ACAN gene, causes dominantly inherited short stature and, in many patients, early-onset osteoarthritis and degenerative disc disease. We aimed to further characterize this phenotypic spectrum with an emphasis on musculoskeletal health. Twenty-two individuals from nine families were enrolled. Histories and examinations focused on joint health, gait analysis, joint specific patient reported outcomes, and imaging studies were performed. All patients had dominantly inherited short stature, with the exception of a de novo mutation. Short stature was worse in adults versus children (median height -3.05 SD vs. -2.25 SD). ACAN mutations were not always associated with bone age advancement (median advancement +1.1 years, range 0 to +2 years). Children had subtle disproportionality and clinically silent joint disease-25% with osteochondritis dissecans (OD). Adults had a high prevalence of joint symptomatology-decline in knee function, disability from spinal complaints, and lower physical activity on outcome measures. Osteoarthritis (OA) and OD was detected in 90% of adults, and orthopedic surgeries were reported in 60%. Aggrecan deficiency leads to short stature with progressive decline in height SD, mild skeletal dysplasia, and increasing prevalence of joint pathology over time. Optimal musculoskeletal health and quality of life can be attained with timely identification of pathology and intervention.

Few young athletes meet newly derived age- and activity-relevant functional recovery targets after ACL reconstruction.

PURPOSE: National registry data have established Knee injury and Osteoarthritis Outcome Score (KOOS) functional recovery target values for adults after anterior cruciate ligament (ACL) reconstruction. However, the specificity of these target values for young athletes after ACL reconstruction is unclear. The purpose of this analysis was to (1) derive age- and activity-relevant KOOS functional recovery target values from uninjured young athlete data and (2) determine clinical measures at the time of RTS clearance associated with meeting the newly-derived functional recovery target values in young athletes following ACLR. METHODS: Two hundred and twenty-two young athletes (56 uninjured controls, 17.2 ± 2.4 years, 73% female; 166 after ACL reconstruction, 16.9 ± 2.2 years, 68% female) were included in this cross-sectional analysis from a larger cohort study. Uninjured control participants completed the KOOS, and functional recovery target values were defined as the lower bound of the 95% confidence interval for KOOS subscales. ACL reconstruction participants completed testing within 4 weeks of return-to-sport clearance, including the KOOS, single-leg hop tests, and isometric quadriceps strength. In ACL reconstruction participants, logistic regression was used to determine predictors of meeting all KOOS functional recovery target values (primary outcome) among demographic/injury, hop, and strength data (α ≤ 0.05). RESULTS: KOOS functional recovery target values for each subscale from uninjured athlete data were: Pain ≥ 94, Symptoms ≥ 92, Activities of Daily Living ≥ 97, Sport ≥ 92, and Quality-of-Life ≥ 92. At the time of return-to-sport clearance, ACL reconstruction participants met the KOOS functional recovery targets in the following proportions: Pain, 63%; Symptoms, 42%; Activities of Daily Living, 80%; Sport, 45%; Quality-of-Life, 24%; overall functional recovery (met all subscale targets), 17%. In ACL reconstruction participants, significant predictors of overall functional recovery (primary outcome) were: younger age, hamstring graft, pediatric ACL reconstruction, quadriceps strength limb-symmetry index > 90%, single-hop limb-symmetry index > 90%, and crossover-hop limb-symmetry index > 90%. CONCLUSIONS: KOOS functional recovery target values derived from uninjured young athletes were higher than those previously reported. Small proportions of young athletes following recent RTS clearance after ACLR met these newly-derived functional recovery target values, and factors associated with meeting functional recovery target values included younger age, hamstring autograft and pediatric ACLR, and having > 90% LSI for quadriceps strength and single-leg hop tests. LEVEL OF EVIDENCE: I.

Does sex affect second ACL injury risk? A systematic review with meta-analysis.

OBJECTIVE: To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport. DESIGN: Systematic review with meta-analysis. DATA SOURCES: Systematic search of five databases conducted in August 2019. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction. RESULTS: Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I2=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I2=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I2=35%). CONCLUSION: Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small. REGISTRATION: PROSPERO (CRD42020148369).

Treatment after ACL injury: Panther Symposium ACL Treatment Consensus Group.

Treatment strategies for ACL injuries continue to evolve. Evidence supporting best practice guidelines to manage ACL injury is largely based on studies with low-level evidence. An international consensus group of experts was convened determine consensus regarding best available evidence on operative versus non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative versus non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organising Committee and Session Chairs. Panel participants reviewed preliminary statements prior to the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty per cent agreement was defined a priori as consensus. A total of 11 of 13 statements on operative versus non-operative treatment of ACL injury reached consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting and pivoting sports, early anatomical ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomical ACL reconstruction is indicated. The consensus statements derived from international leaders in the field may assist clinicians in deciding between operative and non-operative treatment with patients after an ACL injury Level of evidence: Level V.

Treatment after anterior cruciate ligament injury: Panther Symposium ACL Treatment Consensus Group.

Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance toward consensus opinions regarding the best available evidence on operative vs. non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative vs. non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, were convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organizing Committee and Session Chairs for the three working groups. Panel participants reviewed preliminary statements prior to the meeting and provided the initial agreement and comments on the statement via an online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty percent agreement was defined a-priori as consensus. A total of 11 of 13 statements on operative v. non-operative treatment of ACL injury reached the consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting, and pivoting sports, early anatomic ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomic ACL reconstruction is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and non-operative treatments with patients after an ACL injury.Level of evidence V.

Lower patient-reported function at 2 years is associated with elevated knee cartilage T1rho and T2 relaxation times at 5 years in young athletes after ACL reconstruction.

PURPOSE: The purpose was to test the following hypotheses: (1) magnetic resonance imaging (MRI) markers of early knee cartilage degeneration would be present in the involved limb of young athletes after anterior cruciate ligament reconstruction (ACLR) and (2) poor knee function would be associated with MRI markers of cartilage degeneration. METHODS: Twenty-five young athletes after primary, unilateral ACLR (mean age, 16.7 years) were followed to 5-year post-return-to-sport (RTS) clearance, as a part of a larger, prospective cohort study in young athletes post-ACLR. At 2-year post-RTS, patient-reported knee function was evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS). At 5-year post-RTS, qualitative MRI sequences (3 T) and quantitative T1rho and T2 maps segmented into six regions at the femur and tibia were performed for the involved and uninvolved knee cartilages. Relaxation times were compared between knees using Holm-corrected paired t tests. Linear regression was used to examine the association between KOOS scores at 2 years and relaxation times at 5 years. RESULTS: Elevated T1rho and T2 relaxation times were observed in the involved knee at the anterior medial femoral condyle compared to the uninvolved knee (p = 0.006, p = 0.024, respectively). Lower KOOS-Pain, KOOS-Symptoms, KOOS-ADL, and KOOS-Sport scores at 2-year post-RTS were associated with higher T1rho or T2 relaxation times in various regions of the involved knee at 5-year post-RTS (all p < 0.05). CONCLUSIONS: MRI markers of early cartilage degeneration were identified in the medial compartment of the involved knee in young athletes 5-year post-RTS after ACLR. Lower KOOS scores at 2-year post-RTS were associated with elevated knee cartilage T1rho and T2 relaxation times at 5-year post-RTS. Evaluating patient-reported function over time after ACLR appears to provide insight into future degenerative changes in the knee cartilage matrix.

Young athletes after ACL reconstruction with quadriceps strength asymmetry at the time of return-to-sport demonstrate decreased knee function 1 year later.

PURPOSE: Quadriceps femoris (QF) strength deficits at return-to-sport (RTS) after ACL reconstruction (ACLR) contribute to decreased knee function at the same time point. However, the impact of QF strength at RTS on longitudinal function has not been examined. The purpose of this study was to test the hypothesis that young athletes after ACLR with QF strength asymmetry at RTS would demonstrate decreased knee-related function and lower proportions of functional recovery at 1 year post-RTS compared to young athletes following ACLR with nearly symmetric QF strength at RTS. METHODS: Participants included 76 young athletes (74% female; mean age at RTS = 17.3 years) after primary, unilateral ACLR, cleared to RTS, and followed for 1 year after RTS. At the time of RTS, QF strength was quantified on an isokinetic dynamometer and a Limb Symmetry Index (LSI) was calculated [(involved/uninvolved) × 100%]. The cohort was subdivided into two groups based on RTS QF LSI: high quadriceps (HQ; LSI ≥ 90%; n = 36) and low quadriceps (LQ; LSI < 85%; n = 36). The cohort was followed for 1 year post-RTS, and knee-related function was assessed using the International Knee Documentation Committee subjective form (IKDC), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and LSI of single-leg hop tests. Functional recovery at 1 year post-RTS was defined as KOOS scores above literature-reported cut-offs. RESULTS: While the HQ group demonstrated higher symmetry on all 1 year post-RTS hop tests, only the triple-hop test (p = 0.020) was found to be statistically different. Similarly, while the HQ group scored higher on all 1 year post-RTS self-reported knee function measures, only differences on the KOOS-Sport/Rec score (p = 0.039) and IKDC score (p = 0.011) were statistically different. Additionally, the HQ group demonstrated higher proportions of functional recovery at 1 year post-RTS than the LQ group on the KOOS-Symptoms (HQ: 88.9%, LQ: 69.4%; p = 0.040) and KOOS-Sport/Rec (HQ: 91.7%, LQ: 69.4%; p = 0.017). CONCLUSIONS: Young athletes after ACLR with QF strength asymmetry at RTS demonstrated decreased knee-related function and lower proportions of functional recovery at 1 year post-RTS. However, group differences did not exceed reported minimal clinically important difference values. Further study is warranted to understand factors that contribute to longitudinal knee function after ACLR. Clinicians should focus on restoring symmetric QF strength at RTS after ACLR, which may promote higher longitudinal knee function. LEVEL OF EVIDENCE: Level II, Prospective cohort study.

Real-time optimized biofeedback utilizing sport techniques (ROBUST): a study protocol for a randomized controlled trial.

BACKGROUND: Anterior cruciate ligament (ACL) injuries in female athletes lead to a variety of short- and long-term physical, financial, and psychosocial ramifications. While dedicated injury prevention training programs have shown promise, ACL injury rates remain high as implementation has not become widespread. Conventional prevention programs use a combination of resistance, plyometric, balance and agility training to improve high-risk biomechanics and reduce the risk of injury. While many of these programs focus on reducing knee abduction load and posture during dynamic activity, targeting hip extensor strength and utilization may be more efficacious, as it is theorized to be an underlying mechanism of injury in adolescent female athletes. Biofeedback training may complement traditional preventive training, but has not been widely studied in connection with ACL injuries. We hypothesize that biofeedback may be needed to maximize the effectiveness of neuromuscular prophylactic interventions, and that hip-focused biofeedback will improve lower extremity biomechanics to a larger extent than knee-focused biofeedback during dynamic sport-specific tasks and long-term movement strategies. METHODS: This is an assessor-blind, randomized control trial of 150 adolescent competitive female (9-19 years) soccer players. Each participant receives 3x/week neuromuscular preventive training and 1x/week biofeedback, the mode depending on their randomization to one of 3 biofeedback groups (hip-focused, knee-focused, sham). The primary aim is to assess the impact of biofeedback training on knee abduction moments (the primary biomechanical predictor of future ACL injury) during double-leg landings, single-leg landings, and unplanned cutting. Testing will occur immediately before the training intervention, immediately after the training intervention, and 6 months after the training intervention to assess the long-term retention of modified biomechanics. Secondary aims will assess performance changes, including hip and core strength, power, and agility, and the extent to which maturation effects biofeedback efficacy. DISCUSSION: The results of the Real-time Optimized Biofeedback Utilizing Sport Techniques (ROBUST) trial will help complement current preventive training and may lead to clinician-friendly methods of biofeedback to incorporate into widespread training practices. TRIAL REGISTRATION: Date of publication in ClinicalTrials.gov: 20/04/2016. ClinicalTrials.gov Identifier: NCT02754700 .

Influence of Age on Postconcussive Postural Control Measures and Future Implications for Assessment.

OBJECTIVE: To examine the influence of age, sex, attention-deficit hyperactivity disorder (ADHD) status, previous history of concussion, and days since injury on postconcussion postural control assessment in adolescents who have suffered a concussion. DESIGN: Prospective cohort study. SETTING: Hospital-based outpatient clinic. PARTICIPANTS: Seventy-one participants (42 males; 29 females) with mean age 14.14 ± 2.44. INDEPENDENT VARIABLES: Age, sex, previous concussion history, ADHD status, total and severity of postconcussion symptoms, and days since injury. MAIN OUTCOME MEASURES: Total Balance Error Scoring System score, path length, center-of-pressure (COP) area, sample entropy, and Romberg quotient. RESULTS: Pearson product-moment correlation coefficients were calculated to test for potential associations between the continuous participant characteristics and the postural control variables. Spearman correlation was used to test the association between symptom severity and the postural control variables. Standard multiple regression was used to model the extent to which participant characteristics accounted for the variance in the postural sway variables. Age was significantly associated with all of the postural sway variables except COP area for the eyes open condition and sample entropy in the anterior-posterior direction for the eyes closed condition. Sex, ADHD status, and previous concussion history did not significantly predict postural control scores. CONCLUSIONS: Age significantly influences scores on common postconcussion postural control assessments. CLINICAL RELEVANCE: This study demonstrates that age is a critical factor that needs to be accounted for to improve the clinical appropriateness and utility of current postconcussion postural control assessments.

Booster visits in the management of the acute musculoskeletal injuries: Transforming care to improve outcomes-A perspective review.

The current healthcare delivery system for patients with acute musculoskeletal injury is failing. Current rehabilitation management of acute musculoskeletal injury typically includes physical therapy, focused on management of impairments, with an eventual transition to functional activities and release to prior level of function. At that point, formal physical therapy is often discontinued, despite the knowledge that a high percentage of patients fail to maintain preinjury level of activity and often reduce participation in regular physical activity. Further, for those who attempt to return to prior levels of pivoting and cutting activities, there is a high second injury rate. The long-term human experience is compromised by the current model of care which terminates at the point of transition to activity. This model of care fails to meet the continued needs of these patients and may result in long term deficits and potential disability. Extended care models include intermittent follow up visits after discharge from an acute episode of care and have been efficacious and cost effective in some patient populations with musculoskeletal conditions. Specifically, a type of extended care model, labeled "booster sessions," represents an opportunity to provide structured, intermittent care to assist in a smooth transition back to function, following an acute episode of care and promote a healthier life outcome. This perspective review will discuss the opportunity to transform acute musculoskeletal care to booster visit care model in an attempt to develop a more efficacious and cost-effective system of care which could be generalizable to all musculoskeletal conditions.

The Influence of Strength and Sport Exposure on Psychological Readiness After ACL Reconstruction.

BACKGROUND: Among young athletes returning to sport after anterior cruciate ligament reconstruction (ACLR), the extent to which psychological readiness is influenced by factors beyond the psychological domain is largely unknown. HYPOTHESIS: Young athletes with recent sport exposure and higher quadriceps strength will demonstrate higher psychological readiness within 8 weeks of medical clearance to return to sport (RTS) after ACLR. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 38 young athletes after primary ACLR completed testing within 8 weeks of medical clearance to RTS. All participants completed isometric knee extension strength testing, in addition to the ACL Return to Sport after Injury (ACL-RSI) questionnaire. Athletes who participated in sport between time of medical clearance to RTS and date of study enrollment were categorized as SPORT-YES. Those who had not yet participated in sports were categorized as SPORT-NO. Multiple linear regression analyses were used to determine differences in ACL-RSI scores based on quadriceps strength and sport exposure status, while adjusting for age and sex. RESULTS: Of the 38 participants, 20 (52.6%) were categorized as SPORT-YES. The regression model estimating overall ACL-RSI score (P < 0.01, adjusted R2 = 0.389) included significant independent contributions from age, sex, and sport exposure variables (age: P = 0.01, ß [95% CI] = -2.01 [-3.54, -0.48]; sex (male): P = 0.02, ß [95% CI] = 12.50 [2.36, 22.64]; strength: P = 0.51, ß [95% CI] = -2.47 [-10.07,5.13]; sport exposure: P < 0.01, ß [95% CI] = 12.89 [3.58, 22.19]). CONCLUSION: In partial accordance with our hypothesis, recent sport exposure was significantly associated with higher ACL-RSI scores among young athletes in the weeks after medical clearance to RTS after ACLR, while quadriceps strength was not. CLINICAL RELEVANCE: Future prospective work is needed to determine the existence and direction of causal relationships between exposure to sport environment and psychological readiness among young athletes after ACLR.

Internal consistency and validity of the QuickDASH instrument for upper extremity injuries in older children.

BACKGROUND: The short version of the Disabilities of the Arm, Shoulder and Hand instrument (QuickDASH) has been shown to be a valid, reliable, and responsive measure of upper extremity function in adults. However, the psychometric properties of the QuickDASH for younger patients have not been well established. The purpose of this study was to evaluate the internal consistency and validity of the QuickDASH for use with older children and adolescents. METHODS: The QuickDASH and PedsQL instruments were administered to 149 patients grouped into ages 8 to 12 and 13 to 18 years. RESULTS: Item response analysis showed a low SE of measurement (0.06) and a high coefficient α (0.91), suggesting high internal consistency among items. The QuickDASH was found to be a predictor of PedsQL score for both groups (P<0.01). CONCLUSIONS: The results indicate that the QuickDASH is a consistent and valid instrument for older children and adolescents with upper extremity pathology. LEVEL OF EVIDENCE: III, case series.

Responding to exercise-deficit disorder in youth: integrating wellness care into pediatric physical therapy.

THE PROBLEM: The decline and disinterest in regular physical activity among contemporary youth have created an immediate need to identify and treat these youngsters before they become resistant to our interventions. KEY POINTS: Exercise-deficit disorder is a term used to describe a condition characterized by reduced levels of physical activity that are inconsistent with current public health recommendations. Pediatric physical therapists are in an enviable position to identify and treat exercise-deficit disorder in youth, regardless of body size or physical ability. RECOMMENDATION: If pediatric physical therapists want to become advocates for children's health and wellness, there is a need to address limitations in the physical therapist professional curriculum, educate families on the benefits of wellness programming, and initiate preventive strategies that identify youth who are inactive, promote daily physical activity, and encourage healthy lifestyle choices.

The effect of sex and age on isokinetic hip-abduction torques.

CONTEXT: As high school female athletes demonstrate a rate of noncontact anterior cruciate ligament (ACL) injury 3-6 times higher than their male counterparts, research suggests that sagittal-plane hip strength plays a role in factors associated with ACL injuries. OBJECTIVE: To determine if gender or age affect hip-abductor strength in a functional standing position in young female and male athletes. DESIGN: Prospective cohort design. SETTING: Biomechanical laboratory. PARTICIPANTS: Over a 3-y time period, 852 isokinetic hip-abduction evaluations were conducted on 351 (272 female, 79 male) adolescent soccer and basketball players. INTERVENTION: Before testing, athletes were secured in a standing position, facing the dynamometer head, with a strap secured from the uninvolved side and extending around the waist just above the iliac crest. The dynamometer head was positioned in line with the body in the coronal plane by aligning the axis of rotation of the dynamometer with the center of hip rotation. Subjects performed 5 maximum-effort repetitions at a speed of 120°/s. The peak torque was recorded and normalized to body mass. All test trials were conducted by a single tester to limit potential interrater test error. MAIN OUTCOME MEASURE: Standing isokinetic hip-abduction torque. RESULTS: Hip-abduction torque increased in both males and females with age (P < .001) on both the dominant and nondominant sides. A significant interaction of gender and age was observed (P < .001), which indicated that males experienced greater increases in peak torque relative to body weight than did females as they matured. CONCLUSIONS: Males exhibit a significant increase in normative hip-abduction strength, while females do not. Future study may determine if the absence of similar increased relative hip-abduction strength in adolescent females, as they age, may be related to their increased risk of ACL injury compared with males.

Leveraging the construct of physical literacy to promote physical activity for youth with obesity - A qualitative analysis of physical therapists' perceptions.

Background: Promoting physical activity has been identified as a pillar of obesity treatment and prevention. However, youth with obesity often present with physical, affective, and environmental barriers to physical activity engagement. The construct of physical literacy, which has garnered international attention as a holistic approach to understanding human movement, may improve physical activity promotion strategies for youth with obesity. However, literature has shown that healthcare providers are not engaged with the construct of physical literacy. Methods: This qualitative study utilized a phenomenological approach and interpretivist epistemology. Three phases of data collection included member checks, semi-structured interviews, and a focus group with physical therapists treating youth with orthopedic and sport injuries. Simultaneous data collection and inductive analysis was designed to identify themes reflecting how participants utilized the construct of physical literacy to promote physical activity in a clinical setting. Results: Four overarching themes were identified in our analysis as strategies for promoting activity and physical literacy development: 1) Movement Experience, 2) Individualized Care, 3) Movement Momentum, and 4) External Factors. Conclusion: The findings from this study highlight the usefulness of applying a physical literacy lens within physical activity promotion efforts among youth, which may be particularly important for youth with obesity. A high value was placed on the affective and behavioral determinants of physical activity. By applying a physical literacy lens, healthcare providers treating youth with obesity may be better equipped to address barriers and promote participation in physical activities that are enjoyable and build confidence. The findings from this study provide a foundation for future studies examining how healthcare providers can leverage the construct of physical literacy to improve physical activity outcomes among youth.

Predictions of total work based on measures of muscle strength and hop performance in individuals after ACL reconstruction.

OBJECTIVES: The purpose of this study was to determine the ability to utilize clinical measures of hop performance and thigh muscle strength to predict total limb work, a measure of cumulative single leg power, in young athletes at the time of return to sport after ACLR. We hypothesized that hop test performance and thigh muscle strength would predict total limb work during a maximal effort repeated vertical single-leg jump and that hop test performance would better predict total limb work during a maximal effort repeated vertical single-leg jump than measures of thigh strength. DESIGN: Cross-sectional study. PARTICIPANTS: Analysis on data from 50 individuals after unilateral ACLR (74% women, age 14-23 years) MAIN OUTCOME MEASURES: Performed 10-s repeated vertical single-leg jump test on a force platform where single limb power and resultant total work were calculated. At the same session, participants completed a clinical single leg hop test battery and thigh strength testing. RESULTS: All clinical measures were associated with total work during the repeated vertical single-leg jump test on the involved and uninvolved limbs, respectfully. After controlling for height and weight, quadriceps femoris peak torque at 180°/s was the strongest predictor of total work for both limbs. On the involved limb, performance on the triple hop test for distance also uniquely contributed to the prediction of total work. CONCLUSIONS: Quadriceps femoris muscle strength and distance hop test performance predict total limb work capacity of the involved limb during a single-leg dynamic task. Optimizing both measures after ACLR may positively impact vital components of sports performance.

The Association of Physical Competence With Psychological Response Among Young Athletes at Time of Return to Sport After ACL Reconstruction.

BACKGROUND: The traditional index of return-to-sport (RTS) readiness after anterior cruciate ligament reconstruction (ACLR) is the achievement of physical competence criteria. Emerging research indicates that psychological response and self-perceptions of physical competence may be critical mechanisms for successful RTS among young athletes. HYPOTHESIS: Young athletes with higher actual physical competence (APC) and perceived physical competence (PPC) will demonstrate a more positive psychological response at the time of RTS after ACLR. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 41 young athletes after primary ACLR completed testing within 8 weeks of medical clearance to RTS. APC was measured with isokinetic knee extension strength, single-limb crossover hop for distance, and the Knee injury and Osteoarthritis Outcome Score. PPC was measured with the Athletic Competence subscale of the Self-Perception Profile. Criteria for APC and PPC were based on established age- and activity-relevant cutoff scores. Different constructs of psychological response were assessed with the adapted Sport Motivation Scale, Brief Resilience Scale, and Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) total and subscale scores (Emotions, Confidence, and Risk Appraisal). Multiple linear regression analyses were used to determine differences in measures of psychological response based on achievement of APC and PPC, while adjusting for age and sex. RESULTS: Of the 41 participants, 10 (24.4%) met all criteria for APC and 22 (53.7%) met the PPC criteria. The regression models estimating the ACL-RSI score (P < .001; adjusted R2 = 0.331), ACL-RSI Emotions score (P < .001; adjusted R2 = 0.427), and ACL-RSI Risk Appraisal score (P = .013; adjusted R2 = 0.212) were statistically significant. Although APC was not associated with any measure of psychological response, meeting PPC criteria, younger age, and male sex were found to be associated with a more positive psychological readiness to RTS, but not with motivation or resilience. CONCLUSION: Meeting PPC criteria was associated with higher psychological readiness to RTS among young athletes after ACLR, while meeting APC criteria was not associated with any construct of psychological response.