Running Injuries During Adolescence and Childhood

Clinical assessment, treatment, and referral trends for adolescent runners seeking care at an injured runners' clinic

PURPOSE

Over a 10-year time frame, this study aimed to evaluate diagnosis, treatment, and referral trends for adolescent runners seeking care for running-related injuries (RRIs) at a clinic that specializes in running medicine.

METHODS

This study was a retrospective chart review of 392 adolescent runners (2,326 encounters) who sought care for RRIs between the years 2011 and 2021. Descriptive statistics were used to summarize clinical assessments, referrals, assistive devices, and medications prescribed or administered overall and by injury type. Chi-square analyses were used to compare proportions of services rendered across the 10-year time frame.

RESULTS

Patients most frequently received manual evaluations or special tests during clinic visits. Most visits resulted in at least one referral (91%), primarily for physical therapy or gait-training. Assistive devices and medications/supplements were offered at only 18% of patient visits. The majority of assessments (X2 = 69.7, p = 0.002), treatments (X2: 23.6-43.8, p: <  0.001-0.003), and referrals (X2 = 132, p <  0.001) were for shin injuries. Larger proportions of nutrition assessments (X2 = 40.7, p <  0.001), interventions (X2 = 26.8, p = 0.003), and referrals (X2 = 27.5, p = 0.002) were performed in or after the year 2015.

CONCLUSION

Clinic visits for shin injuries required the most clinical resources per episode of care. There were observed shifts in clinical assessment and treatment approaches to include more expanded nutritional and physiologic considerations.

Outpatient Runners Clinic Visit Trends and Injury Characteristics Among 392 Child and Adolescent Patients: A 10-year Chart Review

OBJECTIVE

To evaluate clinic visits and running-related injury (RRI) characteristics among child and adolescent runners seeking care at an outpatient clinic over a 10-year time frame.

DESIGN

Retrospective chart review.

SETTING

Outpatient hospital-affiliated Injured Runners Clinic.

PATIENTS

Children and adolescent runners (6-17 years) with RRIs.

INDEPENDENT VARIABLES

We examined electronic medical records (EMRs) among child and adolescent patients in the hospital database from 2011 to 2021 to obtain RRI characteristics and key demographic factors.

MAIN OUTCOME MEASURES

We assessed volume and frequency of patient visits to the clinic by RRI characteristics. Chi square analyses were used to compare the proportion of clinic visits over time and injury trends by body region and diagnosis.

RESULTS

There were 392 patients (sex: 277 F; mean age: 16.1 ± 1.3 years) and an average of 5 clinic visits per diagnosis (5 ± 4 visits; min: 1 visit, max: 31 visits). Number of visits generally increased over time up to 2016 but declined most drastically during the years of the pandemic (2020-2021; χ 2 = 644, P < 0 .001). Of the 654 new injury diagnoses, 77.68% were attributed to repetitive stress. Bone stress injuries to the tibia were the most common RRI (χ 2 = 1940, P < 0 .001; N = 132; 20.2% of all injuries) and constituted most of the clinic visits (χ 2 = 9271, P < 0 .001; N = 591; 25.4% of all visits).

CONCLUSION

We identified that adolescents with overuse injuries, particularly bone stress injuries to the tibia, constituted most of the visits to the outpatient healthcare setting. Clinicians should emphasize injury prevention efforts in clinical practice to reduce RRI burden.

Which Factors Influence Running Gait in Children and Adolescents? A Narrative Review

In recent years, running has dramatically increased in children and adolescents, creating a need for a better understanding of running gait in this population; however, research on this topic is still limited. During childhood and adolescence multiple factors exist that likely influence and shape a child's running mechanics and contribute to the high variability in running patterns. The aim of this narrative review was to gather together and assess the current evidence on the different factors that influence running gait throughout youth development. Factors were classified as organismic, environmental, or task-related. Age, body mass and composition, and leg length were the most researched factors, and all evidence was in favour of an impact on running gait. Sex, training, and footwear were also extensively researched; however, whereas the findings concerning footwear were all in support of an impact on running gait, those concerning sex and training were inconsistent. The remaining factors were moderately researched with the exception of strength, perceived exertion, and running history for which evidence was particularly limited. Nevertheless, all were in support of an impact on running gait. Running gait is multifactorial and many of the factors discussed are likely interdependent. Caution should therefore be taken when interpreting the effects of different factors in isolation.

Acute effects of footwear on running impact loading in the preschool years

The aim of this study was to assess acute effects of footwear conditions (barefoot, minimalist and standard running shoes) on running impact loading in the preschool years. Fourty-eight habitually shod preschool children (26 males and 22 females) were divided into four age groups (3-, 4-, 5- and 6-year-old). Children performed a simple running game in three different conditions. Three-dimensional biomechanical analysis was carried out during overground running. Statistical parametric mapping was performed on the vertical ground reaction force profiles during the stance phase and one-way repeated measures ANOVA on the vertical instantaneous loading rate. Three-year-old children displayed significantly lower vertical ground reaction force values in the barefoot condition compared to minimalist (3-7% stance) and standard running shoes (7-11% stance). There were also differences in vertical instantaneous loading rate, where 3-year-olds had lower loading when barefoot than in minimalist (p = 0.010, d = 1.19) or running shoes (p = 0.045, d = 0.98), despite no differences in the footstrike pattern (mostly rearfoot-midfoot strike). No differences were found for the older children. Running in minimalist shoes did not imitate barefoot running in 3-year-old children. On the contrary, increased loading was observed in minimalist shoes in early running developmental stages.

A Comparison of Factors Associated with Running-Related Injuries between Adult and Adolescent Runners

Background

There are multiple personal and environmental factors that influence the risk of developing running-related injuries (RRIs). However, it is unclear how these key clinical factors differ between adult and adolescent runners.

Purpose

The purpose of this study was to compare anthropometric, training, and self-reported outcomes among adult and adolescent runners with and without lower extremity musculoskeletal RRIs.

Study Design

Cross-sectional study.

Methods

Questionnaire responses and clinical assessment data were extracted from 38 adult runners (F: 25, M: 13; median age: 23 [range 18-36]) and 91 adolescent runners (F: 56, M: 35; median age: 15 [range 14-16]) who underwent a physical injury prevention evaluation at a hospital-affiliated sports injury prevention center between 2013 and 2021. Participants were sub-grouped into those with (adults: 25; adolescents: 38) and those without (adults: 13; adolescents: 53) a history of self-reported RRIs based on questionnaire responses. Multivariate analyses of covariance (MANCOVA) covarying for gender were conducted to compare outcomes across groups.

Results

Adult runners had lower Functional Movement Screen™ (FMS™) scores (mean differences [MD]: -1.4, p=0.01), were more likely to report intentional weight-loss to improve athletic performance (% difference: 33.0%; p:<.001), and more frequently included resistance training into their training routines (% difference: 21.0%, p=0.01) compared to adolescents. Those with a history of RRIs were more likely to report intentional weight-loss compared to uninjured runners (% difference: 21.3; p=0.02) and had shorter single leg bridge durations than those without RRIs (RRI: 57.9±30, uninjured: 72.0±44, p=0.01).

Conclusion

The findings indicate that addressing aspects of biomechanics identified by the FMS™ and behaviors of weight loss as an effort to improve performance may represent targets for the prevention of RRIs for adult and adolescent runners, given the association with history of RRIs.

Level of Evidence

3.

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.

Running-related injuries in middle school cross-country runners: Prevalence and characteristics of common injuries

BACKGROUND

Understanding the prevalence and factors associated with running-related injuries in middle school runners may guide injury prevention.

OBJECTIVE

To determine the prevalence of running-related injuries and describe factors related to a history of injury.

DESIGN

Retrospective cross-sectional study.

SETTING

Survey distributed online to middle school runners.

METHODS

Participants completed a web-based survey regarding prior running-related injuries, training, sleep, diet, and sport participation.

MAIN OUTCOME MEASUREMENTS

Prevalence and characteristics differentiating girls and boys with and without running-related injury history adjusted for age.

PARTICIPANTS

Youth runners (total: 2113, average age,  13.2 years; boys: n = 1255, girls: n = 858).

RESULTS

Running-related injuries were more prevalent in girls (56% vs. 50%, p = .01). Ankle sprain was the most common injury (girls: 22.5%, boys: 21.6%), followed by patellofemoral pain (20.4% vs. 7.8%) and shin splints (13.6% vs. 5.9%); both were more prevalent in girls (p < .001). Boys more frequently reported plantar fasciitis (5.6% vs. 3.3%, p = .01), iliotibial band syndrome (4.1% vs. 1.4%, p = .001) and Osgood-Schlatter disease (3.8% vs. 1.2%, p = .001). Runners with history of running-related injuries were older, ran greater average weekly mileage, ran faster, had fewer average hours of sleep on weekends, skipped more meals, missed breakfast, and consumed less milk (all p < .05). Girls with history of running-related injuries reported higher dietary restraint scores, later age of menarche, more menstrual cycle disturbances, and higher likelihood of following vegetarian diets and an eating disorder diagnosis (all p < .05). Runners with no history of running-related injuries were more likely to have participated in ≥2 years of soccer or basketball (p < .001).

CONCLUSIONS

Most middle school runners reported a history of running-related injuries and certain injuries differing by gender. Modifiable factors with the greatest association with running-related injuries included training volume, dietary restraint, skipping meals, and less sleep. Sport sampling, including participation in ball sports, may reduce running-related injury risk in this population.

Evaluation of COVID-19 Restrictions on Distance Runners' Training Habits Using Wearable Trackers

The COVID-19 pandemic caused widespread disruption to many individuals' lifestyles. Social distancing restrictions implemented during this global pandemic may bring potential impact on physical activity habits of the general population. However, running is one of the most popular forms of physical activity worldwide and one in which it could be maintained even during most COVID-19 restrictions. We aimed to determine the impact of COVID-19 restrictions on runners' training habits through analyzing the training records obtained from their GPS enabled wearable trackers. Retrospective and prospective data were collected from an online database (https://wetrac.ucalgary.ca). Runners' training habits, including frequency, intensity and duration of training, weekly mileage and running locations were analyzed and compared 9 months before and after the start of COVID-19 restrictions in March 2020. We found that runners ran 3 km per week more (p = 0.05, Cohen's d = 0.12) after the start of COVID-19 restrictions, and added 0.3 training sessions per week (p = 0.03, Cohen's d = 0.14). Moreover, runners ran an additional 0.4 sessions outdoors (p < 0.01, Cohen's d = 0.21) but there was no significant change in the intensity or duration of training sessions. Our findings suggested that runners adopted slightly different training regimen as a result of COVID-19 restrictions. Our results described the collective changes, irrespective of differences in response measures adopted by various countries or cities during the COVID-19 pandemic.

Adolescent Running Biomechanics - Implications for Injury Prevention and Rehabilitation

Global participation in running continues to increase, especially amongst adolescents. Consequently, the number of running-related injuries (RRI) in adolescents is rising. Emerging evidence now suggests that overuse type injuries involving growing bone (e.g., bone stress injuries) and soft tissues (e.g., tendinopathies) predominate in adolescents that participate in running-related sports. Associations between running biomechanics and overuse injuries have been widely studied in adults, however, relatively little research has comparatively targeted running biomechanics in adolescents. Moreover, available literature on injury prevention and rehabilitation for adolescent runners is limited, and there is a tendency to generalize adult literature to adolescent populations despite pertinent considerations regarding growth-related changes unique to these athletes. This perspective article provides commentary and expert opinion surrounding the state of knowledge and future directions for research in adolescent running biomechanics, injury prevention and supplemental training.

Youth Distance Running and Lower Extremity Injury: A Systematic Review

Distance running is a popular youth sport. This systematic review identified and examined the effects of youth distance running and lower extremity musculoskeletal injury. Scientific databases were searched from database inception to May 2020. Two hundred and fifty-eight full texts were screened, with nine articles retained for data extraction. Seven of the studies were case reports or case series. Two case reports involved an apophyseal hip fracture. No correlation was found between running mileage or gender and sustaining an injury. Middle school runners reported fewer injuries than high school runners. Cross country accounted for less than 10% of injuries in youth under 15 compared to other track activities. The main finding was a paucity of research. Available literature suggests youth can participate in distance running with minimal adverse effects. One exception may be increased vulnerability to growth plate injury. Additional research is needed, especially in those under 10, as literature in this population is nonexistent.

Youth running consensus statement: minimising risk of injury and illness in youth runners

Despite the worldwide popularity of running as a sport for children, relatively little is known about its impact on injury and illness. Available studies have focused on adolescent athletes, but these findings may not be applicable to preadolescent and pubescent athletes. To date, there are no evidence or consensus-based guidelines identifying risk factors for injury and illness in youth runners, and current recommendations regarding suitable running distances for youth runners at different ages are opinion based. The International Committee Consensus Work Group convened to evaluate the current science, identify knowledge gaps, categorise risk factors for injury/illness and provide recommendations regarding training, nutrition and participation for youth runners.

Internal and External Workload in Youth Basketball Players Who Are Symptomatic and Asymptomatic for Patellar Tendinopathy

OBJECTIVE

To examine the differences in external and internal workload in players with and without patellar tendinopathy.

DESIGN

Nested case-control study.

METHODS

Workload was monitored in 152 players (aged 13-18 years) for a 1-week period, including all practices, games, and conditioning sessions. Players were prescreened into patellar tendinopathy cases and controls without patellar tendinopathy, using the previously validated Oslo Sports Trauma Research Center-patellar tendinopathy questionnaire. Simple linear regression analysis, with adjustment for clustering by team and Bonferroni correction, was used to examine mean differences in measures of external workload (cumulative jump counts and sessions completed) and internal workload (session rating of perceived exertion in arbitrary units) between cases and controls.

RESULTS

A total of 144 players (19 cases, 125 controls) met the inclusion criteria for final analysis. No significant differences were found between players with patellar tendinopathy and those without patellar tendinopathy in the 3 outcomes: jump count (mean difference, 45 jumps; 98.3% confidence interval [CI]: -41, 130; P = .177), basketball sessions completed (mean difference, 0.9; 98.3% CI: -0.3, 2.2; P = .067), and session rating of perceived exertion (mean difference, 346 arbitrary units; 98.3% CI: -459, 1151; P = .260).

CONCLUSION

In the current study, a significant difference in workload was not detected between youth basketball players with patellar tendinopathy and players without patellar tendinopathy. Efforts toward identifying players at early stages of patellar tendinopathy and applying relevant interventions are warranted. J Orthop Sports Phys Ther 2020;50(7):402-408. Epub 6 Sep 2019. doi:10.2519/jospt.2020.9094.

Age-related participation and performance trends of children and adolescents in ultramarathon running

Participation and performance trends as well as the performance differences among sexes in ultra-endurance running have been well described in the adult population; however, less information on such trends existed in youth ultramarathoners. The aim of the present study was to investigate the age-related participation and performance trends of children and adolescent ultramarathoner runners. Data on runners, younger than 19 years of age, competing from 1960 to 2018 in distance-limited ultramarathons of 50 km, 100 km, 50 miles and 100 miles, were analysed. During this period, the number of ultramarathon participation increased, most notably among boys, most runners originated from Europe, and the 50- and 100-km race distances were the most popular. Overall, male runners were faster than female runners, except in the case of European and Oceanian origin, where girls were faster over the 50-km race. The fastest male runners originated from Africa and the fastest girls from Oceania, and the average running speed has largely decreased for both sexes over calendar years. In summary, this study was the first to report details on participation and performance trends in youth ultramarathoners competing in distance-limited ultramarathons.

Radiographic analysis of lower limb alignment in professional football players

INTRODUCTION

To radiographically analyze lower limb alignment in adult asymptomatic professional football players and to correlate these values to clinical measurements.

MATERIALS AND METHODS

Twenty-four asymptomatic players [24.2 (3.6) years] were enrolled. Standard bilateral lower limb anteroposterior weight-bearing radiographs were acquired and clinical measurement of intercondylar/intermalleolar (ICD/IMD) distance was performed. Coronal plane mechanical alignment was assessed by five angles: leg mechanical axis (LMA), lateral proximal femoral angle (LPFA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA). Their values were compared to the reference values for adult population. An inter-individual comparison between right/left and dominant/non-dominant leg was added. The sum of bilateral LMA was correlated against ICD/IMD and against ICD/IMD adjusted for body height.

RESULTS

Football players presented with ICD/IMD of 46.5 (19.8) mm. Two, out of five, lower leg coronal angles showed significant differences (p < 0.001) compared to reference data from literature: LMA 5.8 (3.0)º vs.1.2 (2.2)º and MPTA 83.5 (2.6)º vs. 87.2 (1.5)º. No significant differences between left/right leg and dominant/non-dominant leg were established. Summed up bilateral LMA showed a high correlation to IMD/ICD (r = 0.8395; R² = 0.7048), and even higher to ICD/IMD adjusted for body height (r = 0.8543; R² = 0.7298).

CONCLUSIONS

This study was radiographically confirming increased varus of elite football players toward general population. Apex of the varus deformity was located in the proximal tibia. Clinical measurement of ICD/IMD adjusted for body height highly correlated with the radiographic values of coronal alignment; therefore, it may be used in population studies.

Too much too early? An analysis of worldwide childhood ultramarathon participation and attrition in adulthood

BACKGROUND

Physical inactivity is associated with chronic disease and premature death, but excessive exercise can also lead to injury. Ultramarathon running is popular among adults but has not been assessed in children. To analyze ultramarathon participation in children and to determine if they continue running ultramarathons into adulthood provide some evidence of associated health risks.

METHODS

Race results databases were used to identify ultramarathon finishers under the age of 19 between 1960-2017. Participation trends across calendar years, age groups and different race distances were analyzed and continued participation into adulthood examined.

RESULTS

A total of 7775 finishes by 5418 individual children were recorded worldwide with an increase in ultramarathon finishers over time (P<0.0001), with the greatest number among older age groups (>16 years) and the 50 and 100 km race distances. Less than 25% of childhood ultramarathon runners continued running ultramarathons into adulthood and approximately 12% continued beyond 20 years.

CONCLUSIONS

Childhood participants has been growing exponentially over the last 20 years. While few of those children continue to complete ultramarathons into adulthood, the finding that some have continued well into adulthood suggests there is no obligate serious adverse physical impairment resulting from childhood ultramarathon participation.

Injury and Illness Depicted in Running-Related Films

The perception that children and adolescents have of injury and illness may be influenced by their depiction in sport-related films. The objective of this study was to determine the depiction of injury and illness in a select number of running-related films. A sample of 31 running-related films were analyzed, with a total of 77 injuries/illnesses depicted. The most common injuries/illnesses depicted were categorized as exertional heat exhaustion/stroke (26%), lower leg muscle cramps/not heat related (12%), ankle sprain (9%), knee ligamentous/meniscus injury (6%), exercise-associated collapse/not heat related (6%), and blister of the toe/foot (6%). Overall, 48/67 (64%) of the injuries/illnesses were considered severe emergencies (injury/illness requiring prompt intervention and immediate discontinuation of sport participation). The disposition of 46% of severe emergencies was the immediate continuation of training/competition. Pediatric health care providers, coaching staff, and parents should stress the importance of injury/illness recognition/disclosure and realistic expectations for rehabilitation to pediatric runners.

Youth Distance Running: Strategies for Training and Injury Reduction

Running is a popular sport for children in the United States. However, review of available literature on health effects and safety recommendations for youth running has not been previously conducted. Unique factors for injury include periods of growth during puberty and potential for growth plate injury. Youth runners may benefit from activities that incorporate high-impact loading and multidirectional movement for optimal bone maturation, exercises to strengthen tendons and muscles, and strategies aimed at improving running biomechanics to reduce risk of injury. In addition, addressing lifestyle factors, including nutrition and sleep is essential for a runner's general health. Similar to other sports, sports specialization should not be encouraged in youth runners. Reducing running-related injury in growing children and assessing readiness for running should be based on a combination of physical, emotional, psychological, social, and cognitive factors. Youth runners require individualized training and competition to safely participate in the sport.

The Effects of Endurance Sports on Children and Youth

In the United States, youth participation in sports continues to increase yearly. This increase in participation, in conjunction with the trend toward early sports specialization and year round training, has led to a similar increase in athletically developed injuries. These injuries vary in nature and acuity, with the type of injury often related to the athlete's age, sport, and level of training. Endurance athletes are at an elevated risk of injury as they frequently push their body to the limit during their arduous training. Pediatric endurance athletes can be particularly vulnerable, especially to overuse injuries, given their unique and ever-changing physiological state. It is important to understand the specific challenges facing not only the physical, but also the emotional well-being of these pediatric endurance athletes to maximize performance while minimizing injury and potential long-term sequelae.

Diagnostic Accuracy of a Self-report Measure of Patellar Tendinopathy in Youth Basketball

BACKGROUND

To engage clinicians in diagnosing patellar tendinopathy in large surveillance studies is often impracticable. The Oslo Sports Trauma Research Centre-patellar tendinopathy (OSTRC-P) questionnaire, a self-report measure adapted from the OSTRC questionnaire, may provide a viable alternative.

OBJECTIVES

To evaluate the diagnostic accuracy of the OSTRC-P questionnaire in detecting patellar tendinopathy in youth basketball players when compared to clinical evaluation.

METHODS

Following the STAndards for Reporting of Diagnostic accuracy studies guidelines, the researchers recruited 208 youth basketball players (13-18 years of age) for this prospective diagnostic accuracy validation study. Participants completed the OSTRC-P questionnaire (index test) prior to a clinical evaluation (reference standard) by a physical therapist blinded to OSTRC-P questionnaire results. Sensitivity, specificity, predictive value, likelihood ratio, and posttest probability were calculated. Linear regression was used to examine the association between the OSTRC-P questionnaire severity score and the patellar tendinopathy severity rating during a single-leg decline squat.

RESULTS

The final analysis included 169 players. The OSTRC-P questionnaire had a sensitivity of 79% (95% confidence interval [CI]: 65%, 90%), specificity of 98% (95% CI: 94%, 100%), positive predictive value of 95% (95% CI: 83%, 99%), negative predictive value of 92% (95% CI: 86%, 96%), positive likelihood ratio of 48 (95% CI: 12, 191), and negative likelihood ratio of 0.21 (95% CI: 0.12, 0.37). The posttest probabilities were 95% and 8%, given positive and negative results, respectively. A positive association was found between OSTRC-P questionnaire severity score and single-leg decline squat rating (β = 0.08; 95% CI: 0.03, 0.12; P = .001).

CONCLUSION

The OSTRC-P questionnaire is an acceptable alternative to clinical evaluation for self-reporting patellar tendinopathy and grading its severity in settings involving youth basketball players.

LEVEL OF EVIDENCE

Diagnosis, level 1b. J Orthop Sports Phys Ther 2018;48(10):758-766. Epub 27 Apr 2018. doi:10.2519/jospt.2018.8088.

Single-Leg Squat Performance in Active Adolescents Aged 8-17 Years

Agresta, CE, Church, C, Henley, J, Duer, T, and O'Brien, K. Single-leg squat performance in active adolescents aged 8-17 years. J Strength Cond Res 31(5): 1187-1191, 2017-More than 30 million U.S. adolescents participate in sport and exercise. Lower extremity injury from sport participation accounts for up to 89% of injuries each year. The single-leg squat (SLS) is a simple clinical tool that assesses lower extremity mechanics often associated with injury risk. To date, there is limited information regarding SLS performance in healthy children. Such information could be useful when assessing youth athletes to determine if mechanics demonstrated are different than is to be expected and puts them at the risk for injury. Furthermore, maturity status is thought to influence motor performance. Currently, there is no information regarding the influence of maturity status on SLS performance in adolescents. The purpose of our study was to determine SLS performance in relation to age and maturity level in adolescents. Forty-five children aged 8-17 years were videotaped performing a series of 10 squats using a standardized protocol. Standing height, seated height, and leg length measures were collected. Investigators scored the SLS test using specific scoring criteria. Adolescents were categorized into 3 maturity levels using a peak height velocity calculation. Multiple linear regression analyses and analysis of variance were used to analyze the data. Chronological age was a significant predictor of SLS performance with younger children having poorer SLS scores. Coaches and trainers should consider the chronological age of the youth athlete when assessing SLS performance. Furthermore, tailored training programs by age may help to address faulty areas, like single-leg stability, and improve overall functional performance.