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.

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.

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.

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.

Anterior Cruciate Ligament Rehabilitation for the 10- to 18-Year-Old Adolescent Athlete: Practice Guidelines Based on International Delphi Consensus.

Background: There are 2 treatment options for adolescent athletes with anterior cruciate ligament (ACL) injuries-rehabilitation alone (nonsurgical treatment) or ACL reconstruction plus rehabilitation. However, there is no clear consensus on how to include strength and neuromuscular training during each phase of rehabilitation. Purpose: To develop a practical consensus for adolescent ACL rehabilitation to help provide care to this age group using an international Delphi panel. Study Design: Consensus statement. Methods: A 3-round online international Delphi consensus study was conducted. A mix of open and closed literature-based statements were formulated and sent out to an international panel of 20 ACL rehabilitation experts. Statements were divided into 3 domains as follows: (1) nonsurgical rehabilitation; (2) prehabilitation; and (3) postoperative rehabilitation. Consensus was defined as 70% agreement between panel members. Results: Panel members agreed that rehabilitation should consist of 3 criterion-based phases, with continued injury prevention serving as a fourth phase. They also reached a consensus on rehabilitation being different for 10- to 16-year-olds compared with 17- and 18-year-olds, with a need to distinguish between prepubertal (Tanner stage 1) and mid- to postpubertal (Tanner stages 2-5) athletes. The panel members reached a consensus on the following topics: educational topics during rehabilitation; psychological interventions during rehabilitation; additional consultation of the orthopaedic surgeon; duration of postoperative rehabilitation; exercises during phase 1 of nonsurgical and postoperative rehabilitation; criteria for progression from phase 1 to phase 2; resistance training during phase 2; jumping exercises during phase 2; criteria for progression from phase 2 to phase 3; and criteria for return to sports (RTS). The most notable differences in recommendations for prepubertal compared with mid- to postpubertal athletes were described for resistance training and RTS criteria. Conclusion: Together with available evidence, this international Delphi statement provides a framework based on expert consensus and describes a practice guideline for adolescent ACL rehabilitation, which can be used in day-to-day practice. This is an important step toward reducing practice inconsistencies, improving the quality of rehabilitation after adolescent ACL injuries, and closing the evidence-practice gap while waiting for further studies to provide clarity.

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.

Cadence in youth long-distance runners is predicted by leg length and running speed.

BACKGROUND: Lower cadence has been previously associated with injury in long-distance runners. Variations in cadence may be related to experience, speed, and anthropometric variables. It is unknown what factors, if any, predict cadence in healthy youth long-distance runners. RESEARCH QUESTION: Are demographic, anthropometric and/or biomechanical variables able to predict cadence in healthy youth long-distance runners. METHODS: A cohort of 138 uninjured youth long-distance runners (M = 62, F = 76; Mean ± SD; age = 13.7 ± 2.7; mass = 47.9 ± 13.6 kg; height = 157.9 ± 14.5 cm; running volume = 19.2 ± 20.6 km/wk; running experience: males = 3.5 ± 2.1 yrs, females = 3.3 ± 2.0 yrs) were recruited for the study. Multiple linear regression (MLR) models were developed for total sample and for each sex independently that only included variables that were significantly correlated to self-selected cadence. A variance inflation factor (VIF) assessed multicollinearity of variables. If VIF≥ 5, variable(s) were removed and the MLR analysis was conducted again. RESULTS: For all models, VIF was > 5 between speed and normalized stride length, therefore we removed normalized stride length from all models. Only leg length and speed were significantly correlated (p < .001) with cadence in the regression models for total sample (R2 = 51.9 %) and females (R2 = 48.2 %). The regression model for all participants was Cadence = -1.251 *Leg Length + 3.665 *Speed + 254.858. The regression model for females was Cadence = -1.190 *Leg Length + 3.705 *Speed + 249.688. For males, leg length, cadence, and running experience were significantly predictive (p < .001) of cadence in the model (R2 = 54.7 %). The regression model for males was Cadence = -1.268 *Leg Length + 3.471 *Speed - 1.087 *Running Experience + 261.378. SIGNIFICANCE: Approximately 50 % of the variance in cadence was explained by the individual's leg length and running speed. Shorter leg lengths and faster running speeds were associated with higher cadence. For males, fewer years of running experience was associated with a higher cadence.

Performance on a Motor Control Test in an Asymptomatic Adolescent Population.

BACKGROUND: Low back pain is a condition present during both adulthood and adolescence. Adolescents with low back pain may benefit from treatment focused on improving abdominal muscle performance and motor control. The supine double leg lowering test (SDLLT) may be a reliable measure to assess core stability in adults, but adolescent performance on the SDLLT has not yet been established in the literature. PURPOSE: To examine performance on the SDLLT in healthy adolescents ages 13 to 18 years and describe influences of gender, age, body mass index, and participation in sport. STUDY DESIGN: Cross-Sectional Study. METHODS: Four licensed physical therapists administered the SDLLT with a Stabilizer pressure biofeedback cuff and inclinometer in 90 adolescents without low back pain (females = 41, males = 49) from three schools in a mid-western metropolitan area. Descriptive statistics, independent sample t-tests, two-way analysis of variance, and Pearson correlation coefficients were utilized to analyze the data. RESULTS: Average SDLLT score was 72.36 +/- 12.54 degrees. A significant difference between SDLLT score was present between genders with males performing better than females. No interactions between performance and involvement in sport were demonstrated. CONCLUSIONS: Female and male adolescents appear to perform differently on the SDLLT with a stabilizer and appear to perform worse than scores recorded for adults. The SDLLT may be used to measure motor control in adolescents, but clinicians should utilize age-appropriate data for clinical decision making. LEVELS OF EVIDENCE: Level 2c.

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.

Return-to-sport quadriceps strength symmetry impacts 5-year cartilage integrity after anterior cruciate ligament reconstruction: A preliminary analysis.

Quadriceps femoris strength asymmetry at the time of return to sports participation after anterior cruciate ligament (ACL) reconstruction contributes to worse function and asymmetric landing patterns, but the impact on longitudinal outcomes is not known. This study determined if young athletes after ACL reconstruction with quadriceps femoris strength asymmetry at a return to sports clearance would demonstrate markers of knee cartilage degeneration 5 years later compared to those with symmetric quadriceps femoris strength at return to sports. Participants (n = 27) were enrolled at the time of medical clearance for sports participation (baseline testing) and followed for 5 years. At baseline, quadriceps femoris strength was measured bilaterally and a limb symmetry index was used to divide the cohort into two groups: return to sport clearance with high quadriceps femoris strength (RTS-HQ; limb symmetry index ≥ 90%) and return to sport clearance with low quadriceps femoris strength (RTS-LQ; limb symmetry index < 85%). At 5 years post-baseline, quantitative magnetic resonance imaging (T2 relaxation times (ms): involved knee medial/lateral femoral condyle and tibial plateau) data were collected. Group differences were evaluated with independent samples t tests. At 5 years post-return to sports, the RTS-LQ strength group (n = 14) demonstrated elevated T2 relaxation times at the anterior region of the lateral femoral condyle compared to the RTS-HQ strength group (n = 13). Clinical Significance: Just over 50% of this cohort was cleared for sports participation with involved limb quadriceps femoris strength deficits that may contribute to early markers of knee cartilage degeneration within the subsequent 5 years.

Confidence, ability to meet return to sport criteria, and second ACL injury risk associations after ACL-reconstruction.

This study tested the hypotheses that participants with high knee-related confidence at the time of return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction (ACLR) would have a greater likelihood of meeting RTS criteria and would have a higher likelihood of second ACL injury. Participants completed RTS testing when cleared to RTS. Success was defined as an IKDC score more than or equal to 90 and all limb symmetry index (LSI) scores more than or equal to 90%. Confidence groups were created based on response to the KOOS Quality of Life subscale. Incidence of second ACL injury was tracked for 24 months after RTS. Associations among confidence, success in meeting RTS criteria, and second ACL injury were evaluated. At RTS, 37.7% were classified with high knee-related confidence, 26.4% met RTS criteria and 22.0% sustained a second ACL injury post-RTS. A higher proportion of confident participants met all RTS criteria (p = 0.001). Confident participants were over two times more likely to suffer a second ACL injury (odds ratio [OR] = 2.40; 95% confidence interval [CI]:1.21-5.20) (p = 0.02) and participants who were both confident and met all RTS criteria were 10 times more likely to suffer a second ACL injury (OR = 9.6; 95% CI:1.1, 84.2) (p = 0.02) than those who passed all RTS criteria but lacked knee-related confidence. Clinical significance: Confident, young athletes at the time of RTS after ACLR are more likely to meet all RTS criteria and more likely to sustain a second ACL injury after RTS. Future work must consider how the inclusion of additional factors into RTS criteria may better identify those at high risk for poor outcome after ACLR.

Passing return-to-sport criteria and landing biomechanics in young athletes following anterior cruciate ligament reconstruction.

We sought to evaluate the sagittal plane knee joint loading patterns during a double-leg landing task among young athletes who passed or failed return-to-sport (RTS) criteria following anterior cruciate ligament reconstruction reconstruction (ACLR), and in uninjured athletes. Participants completed quadriceps strength testing, a hop test battery, and the International Knee Documentation Committee subjective form following medical RTS clearance. ACLR participants "passed" RTS criteria (RTS-PASS) if they met ≥90 limb symmetry (%) or score on all measures and were categorized as "failing" (RTS-FAIL) if not. All participants completed three-dimensional motion analysis testing. Sagittal plane kinematic and kinetic variables were calculated during a double-leg drop vertical jump task. Mean limb values and limb symmetry indices (LSI; %) were calculated and compared using a one-way analysis of variance (ANOVA) (for LSI) and mixed between-within ANOVA (for group × limb differences). A total of 205 participants were included, with 39 in the RTS-PASS group, 109 in the RTS-FAIL group, and 57 control groups (CTRLs). The RTS-FAIL group demonstrated lower symmetry values for peak vertical ground reaction force, peak internal knee extension moment, and peak knee flexion angle. Group × limb interactions were observed for peak vertical ground reaction force and peak internal knee extension moment. Involved limb values were reduced in the RTS-PASS and RTS-FAIL groups compared to CTRLs, while the RTS-PASS groups had lower uninvolved limb values compared to the RTS-FAIL and CTRLs. Clinical Significance: Young athletes who pass RTS criteria after ACLR land symmetrically during a double-leg task, but symmetry was achieved by reducing loading on both limbs.

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.

The influence of maturation and sex on pelvis and hip kinematics in youth distance runners.

OBJECTIVES: This study aimed to investigate differences in stance phase pelvic and hip running kinematics based on maturation and sex among healthy youth distance runners. DESIGN: Cross-Sectional. METHODS: 133 uninjured youth distance runners (M = 60, F = 73; age = 13.5 ±â€¯2.7 years) underwent a three-dimensional running analysis on a treadmill at a self-selected speed (2.8 ±â€¯0.6 m·s-1). Participants were stratified as pre-pubertal, mid-pubertal, or post-pubertal according to the modified Pubertal Maturational Observation Scale. Stance phase pelvis and hip range of motion (RoM) and peak joint positions were extracted. Two-way ANCOVAs (sex, maturation; covariate of running velocity) were used with Bonferroni-Holm method to control for multiple comparisons with a target alpha level of 0.05. RESULTS: A two-way interaction between sex and maturation was detected (p = 0.009) for frontal plane pelvic obliquity RoM. Post-hoc analysis identified a maturation main effect only among females (p˂0.008). Pelvic obliquity RoM was significantly greater among post-pubertal (p = 0.001) compared to pre-pubertal females. Significant main effects of sex (p = 0.02), and maturation (p = 0.01) were found for hip adduction RoM. Post-hoc analysis indicated a significant increase in hip adduction RoM from pre-pubertal to post-pubertal female runners (p = 0.001). A significant main effect of sex was found for peak hip adduction angle (p = 0.001) with female runners exhibiting greater maximum peak hip adduction compared to males. CONCLUSIONS: Maturation influences pelvic and hip kinematics greater in female than male runners. Sex differences became more pronounced during later stages of puberty. These differences may correspond to an increased risk for running-related injuries in female runners compared to male runners.

Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort.

BACKGROUND: Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease. PURPOSE: To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest. RESULTS: As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases. CONCLUSION: The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms.

Return-to-Sport Criteria After Anterior Cruciate Ligament Reconstruction Fail to Identify the Risk of Second Anterior Cruciate Ligament Injury.

BACKGROUND: The incidence of second anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) is high in young, active populations. Failure to successfully meet return-to-sport (RTS) criteria may identify adult athletes at risk of future injury; however, these studies have yet to assess skeletally mature adolescent athletes. OBJECTIVE: To determine if failure to meet RTS criteria would identify adolescent and young adult athletes at risk for future ACL injury after ACLR and RTS. The tested hypothesis was that the risk of a second ACL injury after RTS would be lower in participants who met all RTS criteria compared with those who failed to meet all criteria before RTS. DESIGN: Prospective case-cohort (prognosis) study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 159 individuals (age = 17.2 ± 2.6 years, males = 47, females = 112). MAIN OUTCOME MEASURE(S): Participants completed an RTS assessment (quadriceps strength, functional hop tests) and the International Knee Documentation Committee patient survey (0 to 100 scale) after ACLR and were then tracked for occurrence of a second ACL tear. Athletes were classified into groups that passed all 6 RTS tests at a criterion level of 90% (or 90 of 100) limb symmetry and were compared with those who failed to meet all criteria. Crude odds ratios and 95% CIs were calculated to determine if passing all 6 RTS measures resulted in a reduced risk of second ACL injury in the first 24 months after RTS. RESULTS: Thirty-five (22%) of the participants sustained a second ACL injury. At the time of RTS, 26% achieved ≥90 on all tests, and the remaining athletes scored less than 90 on at least 1 of the 6 assessments. The second ACL injury incidence did not differ between those who passed all RTS criteria (28.6%) and those who failed at least 1 criterion (19.7%, P = .23). Subgroup analysis by graft type also indicated no differences between groups (P > .05). CONCLUSIONS: Current RTS criteria at a 90% threshold did not identify active skeletally mature adolescent and young adult athletes at high risk for second ACL injury.

Identification and Predictors of Age-Relevant and Activity-Relevant Hop Test Targets in Young Athletes After Anterior Cruciate Ligament Reconstruction.

CONTEXT: Performance symmetry between limbs (limb symmetry index [LSI] ≥ 90%) on a battery of single-leg hop tests is recommended to inform return-to-sport (RTS) decisions after anterior cruciate ligament (ACL) reconstruction (ACLR). Achieving current hop test symmetry values has not been associated with future clinical outcomes. The identification of age-relevant and activity-relevant target values to benchmark the hop test performance of young athletes post-ACLR may provide greater specificity and clinical relevance for interpretation of hop test data. OBJECTIVE: To identify single-leg hop test-target values for individual-limb performance and symmetry between limbs for athletes without a history of ACL injury and evaluate the proportion of young athletes post-ACLR who met the newly derived target values at the time of RTS clearance. The secondary objective was to test the hypothesis that better function and strength would be associated with achieving the newly derived hop test target values. DESIGN: Cross-sectional study. SETTING: Pediatric medical center and academic medical center. PATIENTS OR OTHER PARTICIPANTS: A total of 159 young athletes (age = 16.9 ± 2.2 years) at the time of RTS clearance after primary, unilateral ACLR and 47 uninjured control athletes (age = 17.0 ± 2.3 years). MAIN OUTCOME MEASURE(S): All participants completed a single-leg hop test battery (single hop, triple hop, and crossover hop for distance [cm], and 6-m timed hop [seconds]). Raw distance values were normalized by body height, and LSI (%) was calculated for each hop test. Target values were defined as the lower bound of the 95% CI for each hop test, using control group data. Participants with ACLR also completed the Knee injury and Osteoarthritis Outcome Score subscales and a quadriceps femoris strength (newton meters/kilogram) assessment. Logistic regression determined predictors of achieving hop test target values in the ACLR group among injury, function, and strength data (P < .05). RESULTS: In the ACLR group, 79% to 84% of participants met the 90% LSI threshold on each hop test. They achieved the target values for surgical-limb performance in the following proportions (% participants): single hop = 29%, triple hop = 24%, crossover hop = 30%, 6-m timed hop = 18%, all hops= 12%. Also, they met the target values for LSI in the following proportions: single hop = 43%, triple hop = 48%, crossover hop = 50%, 6-m timed hop = 69%, all hops = 25%. The only predictor of achieving all hop test targets for surgical-limb performance was greater surgical-limb quadriceps femoris strength (odds ratio = 4.10, P = .007). We noted a trend toward quadriceps femoris strength LSI ≥ 90% (odds ratio = 2.44, P = .058) as a predictor for meeting all hop test symmetry targets. CONCLUSIONS: At the time of RTS post-ACLR, only a small proportion of young athletes achieved the age-relevant and activity-relevant single-leg hop test targets for surgical-limb performance or symmetry between limbs, even though a majority met the traditionally recommended 90% LSI threshold on hop tests.

Changes in Motivation, Socialization, Wellness and Mental Health in Youth Long-Distance Runners During COVID-19 Social Distancing Restrictions.

Purpose: The COVID-19 pandemic impacted the sporting and exercise activities of millions of youth. Running is an activity that could be maintained while social distancing restrictions were implemented during the pandemic. However, a recent study has indicated that youth runners reported lower running distance, frequency, and intensity during COVID-19. The reason for this reduction and the impact on overall well-being is unknown. Therefore, the purpose of this study was to determine if the social distancing restrictions during the 2020 COVID-19 pandemic influenced running motives, socialization, wellness and mental health in youth long-distance runners. Methods: A customized, open online questionnaire was provided to runners 9-19 years of age who participated in long-distance running activities including team/club cross-country, track and field (distances ≥800 m), road races, or recreational running. Participants responded to questions about demographics, motive for running, and wellness (sleep quality, anxiety, running enjoyment, food consumption quality) 6-months before as well as during social distancing restrictions due to COVID-19. Wilcoxon signed rank tests compared differences for ratio data and Chi-square tests were used to compare proportions before and during COVID-19 social distancing restrictions. Statistical significance was set at p ≤ 0.05. Results: A total of 287 youth long-distance runners (male = 124, female = 162, unspecified = 1; age = 15.3 ± 1.7 years; running experience = 5.0 ± 2.3 years) participated. Compared to their pre-COVID-19 responses, youth long-distance runners reported lower overall motivation to run (p < 0.001) and changes to most motive rankings (p < 0.001 to p = 0.71). The proportion of youth running alone increased during COVID-19 (65.8%) compared to pre-COVID-19 (13.8%, p < 0.001). Youth long-distance runners also reported less running enjoyment (p = 0.001), longer sleep duration (p < 0.001), lower sleep quality (p = 0.05), more anxiety (p = 0.043), and lower food quality consumed (p < 0.001) during COVID-19 social distance restrictions. Conclusion: The COVID-19 social distancing restrictions resulted in significant decreases in motivation and enjoyment of running. The removal of competition and team-based interactions likely had a role in these decreases for this population. Continuing team-based activities (e.g., virtual) during social distancing may help with maintaining motivation of youth long-distance runners. Reduced running occurred concurrently with reduced overall well-being of youth long-distance runners during the COVID-19 pandemic.