Running Biomechanics and Clinical Features Among Adolescent Athletes With Lower Leg Chronic Exertional Compartment Syndrome.

OBJECTIVE: To compare clinical measures between patients with chronic exertional compartment syndrome (CECS) and healthy controls and evaluate running biomechanics, physical measurements, and exertional intracompartmental (ICP) changes in adolescent athletes with lower leg CECS. DESIGN: Cross-sectional case-control study. SETTING: Large tertiary care hospital and affiliated injury prevention center. PARTICIPANTS: Forty-nine adolescents with CECS (39 F, 10 M; age: 16.9 ± 0.8 years; body mass index (BMI): 23.1 ± 2.9 kg/m 2 ; symptom duration: 8 ± 12 months) were compared with 49 healthy controls (39 F, 10 M; age: 6.9 ± 0.8 years; BMI: 20.4 ± 3.7 kg/m 2 ). INTERVENTIONS: All participants underwent gait analyses on a force plate treadmill and clinical lower extremity strength and range of motion testing. Patients with chronic exertional compartment syndrome underwent Stryker monitor ICP testing. MAIN OUTCOME MEASURES: Symptoms, menstrual history, and ICP pressures of the patients with CECS using descriptive statistics. Mann-Whitney U and χ 2 analyses were used to compare CECS with healthy patients for demographics, clinical measures, and gait biomechanics continuous and categorical outcomes, respectively. For patients with CECS, multiple linear regressions analyses were used to assess associations between gait biomechanics, lower extremity strength and range of motion, and with ICP measures. RESULTS: The CECS group demonstrated higher mass-normalized peak ground reaction force measures (xBW) compared with controls (0.21 ± 0.05 xBW ( P < 0.001) and were more likely to have impact peak at initial contact ( P = 0.04). Menstrual dysfunction was independently associated with higher postexertion ICP (ß = 14.6; P = 0.02). CONCLUSIONS: The CECS group demonstrated increased total force magnitude and vertical impact transient peaks. In women with CECS, menstrual dysfunction was independently associated with increased postexertion ICP. These biomechanical and physiological attributes may play a role in the development of CECS.

Transference of outdoor gait-training to treadmill running biomechanics and strength measures: A randomized controlled trial.

Outdoor gait-training has been successful in improving pain and reducing contact time during outdoor running for runners with exercise-related lower leg pain (ERLLP). However, it is unclear if these adaptations translate to gold standard treadmill running and clinical strength assessments. The study purpose was to assess the influence of a 4-week outdoor gait-training intervention with home exercises (FBHE) on treadmill running biomechanics and lower extremity strength compared to home exercises alone (HE) among runners with ERLLP. Seventeen runners with ERLLP were randomly allocated to FBHE and HE groups (FBHE: 3 M, 6F, 23 ± 4 years, 22.0 ± 4.6 kg/m2; HE: 3 M, 5F, 25 ± 5 years, 24.0 ± 4.0 kg/m2). Both groups completed eight sessions of home exercises over 4 weeks. The FBHE group received gait-training through wearable sensors to reduce contact time. Treadmill running gait and clinical strength assessments were conducted at baseline and 4-weeks. Multivariate repeated measures analyses of variance were used to assess the influence of group and timepoint for all outcomes. The FBHE group demonstrated significantly decreased contact time at 4-weeks compared to baseline and the HE group (Mean Difference [MD] range: -42 ms - -39 ms; p-range: <0.001-0.02). The FBHE group had significantly increased cadence (MD: +21 steps/min; p = 0.003) and decreased loading impulse (MD: -51, p < 0.001) during treadmill running at 4-weeks compared to the HE group. Strength did not significantly differ adjusting for multiple comparisons (p > 0.007). The outdoor FBHE intervention transferred to favorable changes in treadmill running biomechanics. Clinicians treating runners with ERLLP patients should implement data-driven outdoor gait-training to maximize patient benefits across running locations.

Youth Athletes With Sever's Disease Exhibit Altered Achilles Tendon Ultrasound Characteristics: A Retrospective Case-Control Study.

OBJECTIVES: Calcaneal apophysitis (Sever's disease) is an overuse condition caused by repetitive traction stress to the calcaneal apophysis. Whether Achilles tendon morphology is altered in this young patient population remains unknown. Therefore, we aimed to identify differences in Achilles tendon morphology between youth athletes diagnosed with calcaneal apophysitis and healthy controls. METHODS: This retrospective chart review included 46 patients (n = 23 Sever's disease, 15F/8M, 12.4 ± 2.3 years old) and (n = 23 healthy controls, 13F/10M, 15.9 ± 1.5 years old) who sought care in a Children's Hospital Sports Medicine/Orthopedics Department between 2012 and 2022. We measured ultrasound-derived degree of tendon thickening, Achilles tendon thickness (cm), and cross-sectional area (CSA [cm2]). Separate multivariate analyses of covariance (MANCOVAs) were used to compare degree of thickening, mass-normalized Achilles tendon thickness, and CSA between participant groups, covarying for age. Cohen's d effect sizes were used to assess the magnitude of mean differences and standard error (MDSE) between groups. RESULTS: Young athletes with Sever's disease had a significantly greater degree of tendon thickening with a large effect compared with healthy controls (MDSE: 0.07 [0.01] mm P < .001, d = 1.39). Achilles tendon thickness and CSA did not statistically differ between groups; however, the magnitude of between-group differences for these measures (MDSE: 0.18 [0.05] cm, MDSE: 0.27 [0.07] cm2, respectively) were moderate. CONCLUSIONS: Our findings demonstrate previously unrecognized differences in Achilles tendon morphology between young athletes with clinically diagnosed Sever's disease and healthy controls. Our study supports incorporating diagnostic ultrasound as part of a comprehensive examination to ensure appropriate diagnosis and clinical management for adolescents with heel pain.

Relationship Between Running Biomechanics and Core Temperature Across a Competitive Road Race.

BACKGROUND: Outdoor races introduce environmental stressors to runners, and core temperature changes may influence runners' movement patterns. This study assessed changes and determined relationships between sensor-derived running biomechanics and core temperature among runners across an 11.27-km road race. HYPOTHESIS: Core temperatures would increase significantly across the race, related to changes in spatiotemporal biomechanical measures. STUDY DESIGN: Cross-sectional cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Twenty runners (9 female, 11 male; age, 48 ± 12 years; height, 169.7 ± 9.1 cm; mass, 71.3 ± 13.4 kg) enrolled in the 2022 Falmouth Road Race were recruited. Participants used lightweight technologies (ingestible thermistors and wearable sensors) to monitor core temperature and running biomechanics throughout the race. Timestamps were used to align sensor-derived measures for 7 race segments. Observations were labeled as core temperatures generally within normal limits (<38°C) or at elevated core temperatures (≥38°C). Multivariate repeated measures analyses of variance were used to assess changes in sensor-derived measures across the race, with Bonferroni post hoc comparisons for significant findings. Pearson's r correlations were used to assess the relationship between running biomechanics and core temperature measures. RESULTS: Eighteen participants developed hyperthermic core temperatures (39.0°C ± 0.5°C); core temperatures increased significantly across the race (P < 0.01). Kinetic measures obtained from the accelerometers, including shock, impact, and braking g, all significantly increased across the race (P < 0.01); other sensor-derived biomechanical measures did not change significantly. Core temperatures were weakly associated with biomechanics (|r range|, 0.02-0.16). CONCLUSION: Core temperatures and kinetics increased significantly across a race, yet these outcomes were not strongly correlated. The observed kinetic changes may have been attributed to fatigue-related influences over the race. CLINICAL RELEVANCE: Clinicians may not expect changes in biomechanical movement patterns to signal thermal responses during outdoor running in a singular event.

Biomechanical changes identified during a marathon race among high-school aged runners.

BACKGROUND: Despite the increasing popularity of endurance running competitions among adolescent runners, there is currently limited information regarding expected biomechanical changes across the duration of a long-distance running event, and the relationship between young runners' biomechanics and running performance. Wearable technology offers an ecological means to continuously assess runners' biomechanical data during outdoor running competitions. RESEARCH QUESTION: Do adolescent athletes adopt changes in sensor-derived biomechanics throughout a marathon race, and are there relationships between race performance and biomechanical features among young marathoners? METHODS: Fourteen high-school aged runners (9 M, 5 F; age: 16 ± 1 years, height: 170.8 ± 7.5 cm; mass: 63.6 ± 9.4 kg) wore lace-mounted sensors to record step-by-step biomechanics during a marathon race. Official race segment completion times were extracted across 5 race segments (5-K, 15-K, Half Marathon [21.1-K], 35-K, Marathon [42.2-K]). Within-participant repeated measures of covariance (pace) were conducted to assess changes in biomechanics across the race, with Bonferroni post-hoc comparisons. Pearson's r correlations were performed to assess the relationship between race finish times and biomechanics. RESULTS: Pace was significantly slower (p-range: 0.002-0.005), contact times significantly longer, and stride lengths significantly shorter in the final segment compared to middle segments (p-range: 0.003-0.004). The rate of shock accumulation was significantly higher in the final race segment compared to the first three segments (p-range: 0.001-0.002). Moderate relationships existed between finish times and pace (r = -0.63), stride length (r = -0.62), and contact time (r = 0.51). SIGNIFICANCE: Adolescent runners altered their gait patterns in the final marathon segment compared to earlier segments. Spatiotemporal measures were moderately correlated with race finish times, suggesting a link between faster run pace, increased stride lengths, and reduced contact time for improved running performance during an endurance race.

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.

Adolescent and young adult hip and knee strength profiles relate to running gait biomechanics.

OBJECTIVES: Compare and assess relationships between strength and running biomechanics among healthy adolescents and young adult males and females. DESIGN: Retrospective cohort. SETTING: Clinic. PARTICIPANTS: 802 healthy participants (570 F, 232 M; 16.6 ± 2.3 years). MAIN OUTCOME MEASURES: Mass-normalized knee flexor and extensor strength, hip adductor and abductor strength, hamstrings-to-quadriceps (H:Q), and abductor-to-adductor (Abd:Add) ratios were obtained using hand-held dynamometry. Mass-normalized peak vertical ground reaction force (vGRF), %stance, cadence, and stride length were obtained using an instrumented treadmill. Multivariate analyses of variance were used to compare strength and biomechanics across ages and sexes. Linear regressions were used to assess the relationships between strength and biomechanics, accounting for speed, age, and sex. Independent t-tests were used to compare strength between strength ratio profiles. RESULTS: Strength and running biomechanics significantly differed between sexes (p-range: <0.001-0.05) and age groups (p-range: <0.001-0.02). Strength and strength ratios were significantly associated with increased cadence (p-range:0.001-0.04) and stride lengths (p-range:0.004-0.03), and decreased vGRF (p < 0.001). Lower H:Q ratios had significantly lower strength measures (p < 0.001). Higher Abd:Add ratios had significantly increased abductor strength (p < 0.001). CONCLUSIONS: Strength and running biomechanics differed by sexes and ages. Hip and knee strength and strength ratios were related to select spatiotemporal and kinetic biomechanical features.

Ankle Sprain History Does Not Significantly Alter Single- and Dual-Task Spatiotemporal Gait Mechanics.

CONTEXT: Single- and dual-task walking gait assessments have been used to identify persistent movement and cognitive dysfunction among athletes with concussions. However, it is unclear whether previous ankle sprain injuries confound these outcomes during baseline testing. The purpose of this study was to determine the effects of (1) ankle sprain history and (2) time since prior ankle sprain injury on single- and dual-task spatiotemporal gait outcomes and cognitive measures. DESIGN: Cross-sectional study. METHODS: We assessed 60 college Division-I athletes (31 with ankle sprain history; 13 females and 18 males, 19.3 [0.8] y; 29 with no ankle sprain history, 14 females and 15 males, 19.7 [0.9] y) who completed injury history forms and underwent concussion baseline testing. Athletes completed single- and dual-task gait assessments by walking back and forth along an 8-m walkway for 40 seconds. Athletes wore a smartphone with an associated mobile application on their lumbar spine to record spatiotemporal gait parameters and dual-task cognitive performance. Separate multivariate analyses of variance were used to assess the effects of ankle sprain injury history on spatiotemporal measures, gait variability, and cognitive performance. We performed a multivariate regression subanalysis on athletes who reported time since injury (n = 23) to assess temporal effects on gait and cognitive performance. RESULTS: Athletes with and without a history of ankle sprains had comparable spatiotemporal and gait variability outcomes during single- (P = .42; P = .13) and dual-task (P = .75; P = .55) conditions. Additionally, ankle sprain injury history did not significantly influence cognitive performance (P = .35). Finally, time since ankle sprain did not significantly affect single- (P = .75) and dual-task gait (P = .69), nor cognitive performance (P = .19). CONCLUSIONS: Ankle sprain injury history did not significantly alter spatiotemporal gait outcomes nor cognitive performance during this common clinical assessment. Future studies may consider including athletes with ankle sprain injury history during concussion assessments.

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.

Running gait adaptations among adolescent runners with soft tissue impairments following lateral ankle sprains.

BACKGROUND: Lateral ankle sprains (LAS) frequently lead to residual soft tissue impairments, often attributed to biomechanical dysfunction during movement. OBJECTIVE: To compare running biomechanics between adolescent runners with soft tissue pathologies following LAS (injured) and healthy runners (control) and between limbs. DESIGN: Retrospective cohort study. SETTING: Hospital-affiliated sports injury prevention center. PARTICIPANTS: Twenty-five adolescent runners with a history of LAS and current ankle impingement or tendinopathy (23 female, 2 male; age: 15 ± 2 years; body mass index [BMI]: 19.5 ± 2.5 kg/m2 ; symptom duration: 1.1 ± 0.9 years), and 23 healthy controls without any LAS history (19 female, 4 male; age: 15 ± 1 years; BMI: 19.2 ± 2.7 kg/m2 ) were included in this study. INTERVENTIONS: All participants completed a clinical gait assessment in which they ran at a self-selected speed on a force-plate instrumented treadmill, while two video cameras recorded two-dimensional sagittal and coronal views. MAIN OUTCOME MEASURES: Foot rotation, step width, contact time, and cadence were compared between groups and limbs (involved, uninvolved [or "better" for bilateral cases]) using a multivariate analysis of variance (MANOVA). Rearfoot landing and foot strike type were compared between groups and limbs using a chi-square analysis. RESULTS: The injured group had significantly increased step width (F = 4.71, p = .04; mean difference [MD] with SE: 1.5 [0.7] cm) compared to controls. The injured groups' involved limb had longer contact time (F = 4.62, p = .03; MDgroup : 12 [7] ms, MDlimb : 22 [11] ms) with more internal foot rotation (F = 14.60, p < .001; MDgroup : 2.2 [1.2] degrees, MDlimb : 4.2 [1.3] degrees) compared to controls and their contralateral limb. There were no significant differences for cadence (F = 2.43, p = .13; MD: 4 [3] steps/min), foot landing (X2 = 1.28, p = .53), or foot strike (X2 = 1.24, p = .54). CONCLUSIONS: Spatiotemporal and kinematic running adaptations may predispose young runners with initial LAS to secondary soft tissue dysfunction due to loss of stability from ligamentous structures and an overreliance on myotendinous control. Clinicians may consider targeting these maladaptations during gait-training interventions.

Adolescent exercise-related lower leg pain musculotendinous characteristics.

BACKGROUND: Exercise-related lower leg pain (ERLLP) is one of the most common injuries among adolescent runners; however, there is limited information available on lower extremity musculotendinous characteristics in relationship to injury. Ultrasound imaging has previously been used to evaluate musculotendinous structures among adults with chronic lower limb injuries. Similar measurement approaches may be adopted to assess young runners with ERLLP. OBJECTIVE: To compare ultrasound-derived lower extremity musculotendinous thickness, echogenicity, and muscle fiber pennation angles between adolescent runners with and without ERLLP. DESIGN: Cross-sectional design. SETTING: Hospital-affiliated sports injury prevention center. PARTICIPANTS: Twenty-eight adolescent runners with (N = 14) and without ERLLP (N = 14). INTERVENTIONS: Runners' patellar and Achilles tendons, and tibialis anterior, medial gastrocnemius, abductor hallicus, and flexor digitorum brevis muscles were assessed with ultrasound imaging using standardized procedures. MAIN OUTCOME MEASURES: Separate repeated measures multivariate analyses of covariance (covariate: gender) were used to compare groups and limbs for mass-normalized musculotendinous thickness, musculotendinous echogenicity, and extrinsic ankle muscle fiber pennation angles. RESULTS: The adolescent ERLLP group had reduced average muscle size for all structures except the tibialis anterior compared to the uninjured group (mean difference [MD] range: -0.12-0.49 mm/kg; p range: .002-.05), and reduced average medial gastrocnemius pennation angles on their case limb compared to their contralateral limb and the uninjured group (MD range: -3.7-6.4°; p < .001). The ERLLP group additionally had reduced average patellar and Achilles tendon size (MD range: -0.14--0.15 mm/kg; p range: .02-.03), and lower Achilles tendon echogenicity compared to uninjured counterparts (MD: -18; p = .02). CONCLUSIONS: Adolescent runners with ERLLP exhibited morphological musculotendinous changes that may occur either as a result of or as a contributing factor to pain and persistent dysfunction. The findings highlight key targets for rehabilitation for young, injured runners, particularly intrinsic foot muscle strengthening.

Influence of Reduced-Gravity Treadmill Running on Sensor-Derived Biomechanics.

BACKGROUND: Reduced gravity treadmills have become increasingly prevalent in clinical settings. The purpose of this study was to assess the influence of manipulated levels of bodyweight during reduced gravity treadmill running on sensor-derived spatiotemporal, kinematic, and kinetic measures. HYPOTHESES: Reduced gravity conditions would result in significantly altered biomechanical measures compared with 100% gravity conditions, with the most pronounced effects anticipated in the 20% condition. STUDY DESIGN: Cross-sectional clinic-based study. METHODS: A total of 16 runners (8 male [M; age, 28.88 ± 5.69 years; body mass index [BMI], 25.08 ± 3.74 kg/m2], 8 female [F; age, 28.75 ± 5.23 years, BMI, 21.05 ± 3.46 kg/m2]) participated in this study. Participants wore commercially available sensors on their shoelaces and ran in a reduced gravity treadmill at a self-selected pace for 5 minutes each at 100%, 80%, 60%, 40%, and 20% bodyweight in a randomized order. The pace remained constant across all conditions, and rating of perceived exertion (RPE) was obtained following each condition. Step-by-step spatiotemporal, kinematic, and kinetic metrics were extracted to calculate mean outcome measures for each bodyweight condition. Repeated measures analyses of variance were conducted to assess the influence of the different bodyweight reduction levels on RPE and runners' biomechanics. RESULTS: Higher pressure creating lower bodyweight conditions resulted in significantly increased stride length and decreased cadence, contact time, impact g, and RPE, along with a shift toward forefoot strike types compared with higher body weight conditions (P < 0.01). All other outcomes were comparable across conditions. CONCLUSION: Reduced bodyweight running significantly altered spatiotemporal measures and reduced the vertical component of loading. CLINICAL RELEVANCE: Our findings offer objective information on expected biomechanical changes across pressure levels that clinicians should consider when incorporating reduced gravity treadmill running into rehabilitation plans.

Epidemiology of Lateral Ligament Complex Tears of the Ankle in National Collegiate Athletic Association (NCAA) Sports: 2014-15 Through 2018-19.

BACKGROUND: Epidemiological studies of lateral ankle sprains in NCAA sports are important in appraising the burden of this injury and informing prevention efforts. PURPOSE: To describe the epidemiology of lateral ankle sprains in NCAA sports during the 2014-15 through 2018-19 seasons. STUDY DESIGN: Descriptive epidemiology study. METHODS: Injury and exposure information collected within the NCAA Injury Surveillance Program (ISP) were examined. Counts, rates, and proportions of lateral ankle sprains were used to describe injury incidence by sport, event type (practices, competitions), season segment (preseason, regular season, postseason), injury mechanism (player contact, noncontact, and surface contact, injury history (new, recurrent), and time loss (time loss [≥1 day], non-time loss). Injury rate ratios (IRRs) were used to examine differential injury rates, and injury proportion ratios (IPRs) were used to examine differential distributions. RESULTS: A total of 3910 lateral ankle sprains were reported (4.61 per 10,000 athlete exposures) during the study period, and the overall rate was highest in men's basketball (11.82 per 10,000 athlete exposures). The competition-related injury rate was higher than the practice-related rate (IRR, 3.24; 95% CI, 3.04-3.45), and across season segments, the overall rate was highest in preseason (4.99 per 10,000 athlete exposures). Lateral ankle sprains were most often attributed to player-contact mechanisms in men's (43.2%) and women's sports (35.1%), although injuries were more prevalently attributed to player contact in men's than in women's sports (IPR, 1.23; 95% CI, 1.13-1.34). Overall, 49.7% of all lateral ankle sprains were time loss injuries. CONCLUSIONS: The findings of this study are consistent with previous epidemiological investigations of lateral ankle sprains among NCAA athletes. Results offer additional context on differential injury mechanisms between men's and women's sports and on injury risk across the competitive season. Future research may examine the effectiveness of deploying injury prevention programs before the start of a season.

Adolescent Marathon Training: Prospective Evaluation of Musculotendinous Changes During a 6-Month Endurance Running Program.

OBJECTIVES: Assess changes in lower extremity musculotendinous thickness, tissue echogenicity, and muscle pennation angles among adolescent runners enrolled in a 6-month distance running program. METHODS: We conducted prospective evaluations of adolescent runners' lower extremity musculotendinous changes at three timepoints (baseline, 3 months, and 6 months) throughout a progressive marathon training program. Two experienced researchers used an established protocol to obtain short- and long-axis ultrasound images of the medial gastrocnemius, tibialis anterior, flexor digitorum brevis, abductor hallicus, and Achilles and patellar tendons. ImageJ software was used to calculate musculotendinous thickness and echogenicity for all structures, and fiber pennation angles for the ankle extrinsic muscles. Repeated measures within-subject analyses of variance were conducted to assess the effect of endurance training on ultrasound-derived measures. RESULTS: We assessed 11 runners (40.7% of eligible runners; 6F, 5M; age: 16 ± 1 years; running experience: 3 ± 2 years) who remained injury-free and completed all ultrasound evaluation timepoints. Medial gastrocnemius muscle (F2,20  = 3.48, P = .05), tibialis anterior muscle (F2,20  = 7.36, P = .004), and Achilles tendon (F2,20  = 3.58, P = .05) thickness significantly increased over time. Echogenicity measures significantly decreased in all muscles (P-range: <.001-.004), and increased for the patellar tendon (P < .001) during training. Muscle fiber pennation angles significantly increased for ankle extrinsic muscles (P < .001). CONCLUSIONS: Adolescent runners' extrinsic foot and ankle muscles increased in volume and decreased in echogenicity, attributed to favorable distance training adaptations across the 6-month timeframe. We noted tendon thickening without concomitantly increased echogenicity, signaling intrasubstance tendon remodeling in response to escalating distance.

Intrinsic and extrinsic factors contributing to running-related lower limb injuries among adolescent runners.

The purpose of this study was to assess which combination of intrinsic and extrinsic factors contribute to running-related injury (RRI)among adolescent cross-country, track, and long-distance runners. We conducted a retrospective study at a hospital-affiliated sports injury prevention centre of 130 adolescent runners (F: 62.1%, M: 37.9%; cross-country: 34.1%, track: 56.1%, long-distance running: 9.8%) who underwent an Injury Prevention Evaluation between 2013 and 2021. The evaluation included a questionnaire on personal and training factors, and standardised physical assessments. We used a binomial logistic regression to assess the influence of demographics, lower extremity strength and alignment, training (running volume and intensity, weight training), and dietary factors on RRIs. There were 38 adolescent runners who reported RRIs (ankle sprains: N = 16, shin splints: N = 9, stress fractures: N = 13). Female sex (odds ratio [OR]: 4.58 [1.37, 15.37]; p = 0.01), reduced weekday hours of sleep (OR: 1.75 [1.04, 2.95]; p = 0.04), reduced hip abduction strength (OR: 1.02 [1.00, 1.04]; p = 0.05), and intention to lose weight to improve athletic performance (OR: 4.58 [1.00, 21.28]; p = 0.05) were associated with RRIs. These intrinsic and extrinsic risk factors may represent targets for injury prevention for adolescent runners.

Sensor-based gait training to reduce contact time for runners with exercise-related lower leg pain: a randomised controlled trial.

Objectives: To assess the effects of a 4-week randomised controlled trial comparing an outdoor gait-training programme to reduce contact time in conjunction with home exercises (contact time gait-training feedback with home exercises (FBHE)) to home exercises (HEs) alone for runners with exercise-related lower leg pain on sensor-derived biomechanics and patient-reported outcomes. Design: Randomised controlled trial. Setting: Laboratory and field-based study. Participants: 20 runners with exercise-related lower leg pain were randomly allocated into FBHE (4 male (M), 6 female (F), 23±4 years, 22.0±4.3 kg/m2) or HE groups (3 M, 7 F, 25±5 years, 23.6±3.9 kg/m2). Interventions: Both groups completed eight sessions of HEs over 4 weeks. The FBHE group received vibrotactile feedback through wearable sensors to reduce contact time during outdoor running. Primary and secondary outcome measures: Patient-reported outcome measures (PROMs) and outdoor gait assessments were conducted for both groups at baseline and 4 weeks. PROMs were repeated at 6 weeks, and feedback retention was assessed at 6 weeks for the FBHE group. Repeated measures analyses of variance were used to assess the influence of group and timepoint on primary outcomes. Results: The FBHE group reported increased function and recovery on PROMs beyond the HE group at 6 weeks (p<0.001). There was a significant group by time interaction for Global Rating of Change (p=0.004) and contact time (p=0.002); the FBHE group reported greater subjective improvement and reduced contact time at 4 and 6 weeks compared with the HE group and compared with baseline. The FBHE group had increased cadence (mean difference: 7 steps/min, p=0.01) at 4 weeks during outdoor running compared with baseline. Conclusion: FBHE was more effective than HE alone for runners with exercise-related lower leg pain, manifested with improved PROMs, reduced contact time and increased cadence. Trial registration number: NCT04270565.

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.

Biomechanical running gait assessments across prevalent adolescent musculoskeletal injuries.

BACKGROUND: While there is substantial information available regarding expected biomechanical adaptations associated with adult running-related injuries, less is known about adolescent gait profiles that may influence injury development. RESEARCH QUESTIONS: Which biomechanical profiles are associated with prevalent musculoskeletal lower extremity injuries among adolescent runners, and how do these profiles compare across injury types and body regions? METHODS: We conducted a cross-sectional study of 149 injured adolescents (110 F; 39 M) seen at a hospital-affiliated injured runner's clinic between the years 2016-2021. Biomechanical data were obtained from 2-dimensional video analyses and an instrumented treadmill system. Multivariate analyses of variance covarying for gender and body mass index were used to compare continuous biomechanical measures, and Chi-square analyses were used to compare categorical biomechanical variables across injury types and body regions. Spearman's rho correlation analyses were conducted to assess the relationship of significant outcomes. RESULTS: Patients with bony injuries had significantly higher maximum vertical ground reaction forces (bony: 1.87 body weight [BW] vs. soft tissue: 1.79BW, p = 0.05), and a higher proportion of runners with contralateral pelvic drop at midstance (χ2 =5.3, p = 0.02). Maximum vertical ground reaction forces and pelvic drop were significantly yet weakly correlated (ρ = 0.20, p = 0.01). Foot strike patterns differed across injured body regions, with a higher proportion of hip and knee injury patients presenting with forefoot strike patterns (χ2 =22.0, p = 0.01). SIGNIFICANCE: These biomechanical factors may represent risk factors for injuries sustained by young runners. Clinicians may consider assessing these gait adaptations when treating injured adolescent patients.

Clinical usage, application procedures, and perceived effectiveness of cupping therapy among healthcare professionals in the United States: A cross-sectional survey.

BACKGROUND: Despite its growing popularity since the mid-1900s, the application procedures and factors influencing the usage of cupping therapy among healthcare professionals in the United States remains unclear. Therefore, the purpose of this study was to investigate the clinical usage, application procedures, and perceived effectiveness of cupping therapy among healthcare professionals in the United States. MATERIALS AND METHODS: A convenience sample of 158 healthcare professionals (age: 29.36 ± 7.42 years) participated in this cross-sectional study (completion rate = 86.15%; n = 158/195). A custom web-based survey designed to assess respondents' clinical incorporation of cupping therapy, was disseminated through snowball sampling on various social media platforms. Descriptive statistics including means, standard deviations, and frequencies were calculated per survey item. RESULTS: Ninety-one percent of respondents reported working as an athletic trainer in either a secondary school (30%) or collegiate setting (48%). Dry cupping was the most commonly reported type of cupping therapy (99%), and 75% of respondents reported using both static and moving cupping techniques. Significant differences in cup application time and the amount of air extraction were noted between static and moving cupping. Cupping therapy was reported as most effective for treating muscle tightness, myofascial trigger points, and musculoskeletal pain. CONCLUSION: While the usage and application of cupping therapy may vary based on the type and style of cupping as well as the patient's condition, respondents reported cupping therapy to be an effective method for treating various musculoskeletal conditions.

Influence of the COVID-19 pandemic on running behaviors, motives, and running-related injury: A one-year follow-up survey.

The purpose of this study was to compare running behaviors, motives, and injury during the first full year of the pandemic compared to the year prior, and month of eased restrictions. 466 runners responded to this follow-up survey. Paired t-tests were used to compare timepoints. Logistic regressions were used to assess demographic influences on behaviors. During the first full year of the pandemic, runners were more likely to increase their weekly runs (Mean Differences [MD]: 0.29±0.10, p < .001), yet had fewer motives (MD: -0.20±0.06, p = .02) compared to the month of eased restrictions. 18-25-year-olds were most likely to increase running volume (Odds Ratio [OR]: 2.79 [1.06, 7.32], p = .04) during the first full year of the pandemic compared to the year prior. Inexperienced runners reported fewer motives (OR: 3.00-4.41, p = .02-.04), and reduced sustained runs (OR: 2.36 [1.13, 4.96], p = .02) during the first full year of the pandemic compared to the year prior. Inexperienced runners and runners who lost access to preferred locations were at increased injury risk (OR: 1.98-2.63, p: .01-.04) during the first full year of the pandemic compared to the year prior. Our findings highlight pandemic-related changes among the running community that are likely to influence behaviors and injury risk.