Identifying links between athletic identity and risk factors related to youth sport participation.

Introduction: The development of identity formation occurs during adolescence through experiences, ideals and principle. With greater accessibility to sports, recent trends have shown increased rates of sports specialization over the past decade in youth athletes. Athletic identity measures the strength an individual is tied to the athlete role and can be formed in conjunction to adolescent identity formation. More specialized youth athletes may have stronger ties to their athletic identity during their adolescent identity formation period. Methods: Youth basketball athletes were surveyed on specialization levels and athletic identity via the Athletic Identity Measurement Scale (AIMS), including three submeasures: social identity, exclusivity, and negative affectivity. Results: Participants showed stronger identification to social identity items and the weakest identification with exclusivity items. Athletes reporting more time spent playing their primary sport presented higher scores across all measures of athletic identity, and total athletic identity was stronger in athletes reporting specialization at an earlier age. Exclusivity and negative affectivity tended to increase with specialization level which may primarily be driven by specialized athletes choosing to quit non-primary sports. Discussion: Athletic identity may be worth noting as a psychological indicator of potential risk of injury. The long-term goal of this work is to provide the research and clinical community a greater understanding of a potential psychosocial risk factor as youth athletes continue specializing and spending more time training in a singular sport.

Lower-extremity kinematics and kinetics differ based on drop vertical jump variation: An assessment of methodology for a return-to-play protocol using motion analysis.

BACKGROUND: The drop vertical jump (DVJ) is commonly used in return-to-play evaluations to assess movement quality and risk during a dynamic task. However, across biomechanics literature, a multitude of DVJ variations have been used, influencing the generalizability and potential interpretation of the reported findings. RESEARCH QUESTION: The purpose of this study was to identify differences in lower extremity kinematics and kinetics between DVJ variations that differ based on horizontal jump distance, verbal instructions, and the use of a jump target. METHODS: A single-group repeated measures design was used in a laboratory setting. Twenty participants were tested, and three-dimensional angles and moments of the pelvis, hip, knee, and ankle were computed. Wilcoxon signed rank tests were performed to determine differences between DVJ variations. RESULTS: Reduced knee flexion at initial contact and greater knee extensor moments across the descent phase were observed with increased horizontal jump distance. Additionally, both verbal instructions and a jump target influenced movement strategies at the pelvis, hip, and knee. Ground reaction forces were found to be similar across conditions and jump height following the first landing increased with a target. SIGNIFICANCE: Although subtle, the biomechanical differences observed between task variations emphasize the importance of standardizing motion analysis protocols for research and clinical decision-making. Given the findings of the current study, the authors recommend using the Half Height variation in patients treated for a knee injury as it will likely be the most indicative of movement quality.

Trunk and lower-extremity kinematics differ based on step-down tap variation: An assessment of methodology for a return-to-play protocol using motion analysis.

BACKGROUND: The step-down tap (SDT) is a commonly used task to assess unilateral neuromuscular control and to identify deficient movement patterns of the trunk and lower extremities. However, instruction of the SDT varies greatly in recent reports, which may alter the clinical interpretation of potential movement deficiencies. RESEARCH QUESTION: The purpose of this study was to identify differences in trunk and lower extremity kinematics between variations of a step-down tap that differ based on step direction, fixing the arms or stance foot, and trial collection methods. METHODS: This study followed a single-group repeated measures design in a laboratory setting. Three-dimensional angles of the trunk, hip, and knee of 18 participants were evaluated at 60 degrees of knee flexion and at maximum squat depth during six SDT variations. Wilcoxon signed rank tests were performed to determine the effects of an anterior verse lateral step direction, a fixed arm or stance foot position, and an individual verse continuous trial collection method. RESULTS: Knee flexion, external pelvic rotation, and external trunk rotation were greater in the anterior SDT, while the lateral SDT elicited greater pelvic tilt and hip flexion. Additionally, overall squat depth was greater across participants during the anterior SDT. Few clinically significant differences (≥3°) were observed due to fixing arm or stance foot position, and no differences were identified based on trial collection methods. SIGNIFICANCE: The standardization of task instructions for motion analysis protocols utilized for research purposes and/or clinical decision-making is crucial. Specifically, for the SDT, the authors recommend using the anterior step direction. A fixed arm and stance foot position is not necessary, and trials may be collected individually or continuously based on convenience for a small number of repetitions.

Improvement in balance from diagnosis to return-to-play initiation following a sport-related concussion: BESS scores vs center-of-pressure measures.

OBJECTIVE: Accurate assessment of balance recovery throughout treatment of a sport-related concussion is imperative. This study examined differences in balance from diagnosis to return-to-play initiation in adolescent patients post-concussion. Second, this study investigated the extent to which the Balance Error Scoring System (BESS) correlated with center-of-pressure (COP) measures. METHODS: Forty participants performed the BESS while standing on a force platform such that COP data were obtained simultaneously. Spatial and velocity COP-based measures were computed for the double-stance conditions. RESULTS: BESS scores and COP-based measures indicated improved balance performance between visits. Specifically, 62.5/65.0% of participants exhibited improved firm/foam BESS final scores, respectively, and 56.4-71.8% exhibited improved COP-based measures. However, once normative ranges were referenced to identify maintained performance, the percentage of participants who substantially improved differed from initial findings (BESS: 2.5/7.5%, COP: 48.7-69.2%). Additionally, positive correlations between balance measures were primarily found at diagnosis (r=0.33-0.53), while only three correlations were maintained at return-to-play initiation (r=0.34-0.39). CONCLUSIONS: BESS scores successfully identified poor balance performance at diagnosis when symptoms were most pronounced, but failed to accurately depict performance once balance impairment, indicated by COP-based measures, became less apparent. Further work is needed to implement more advanced balance assessments into clinical environments.

Plantar Pressures Following Surgical Release in Children With Clubfoot: Comparison of Posterior Release, Posteromedial Release, and Nonoperative Correction.

BACKGROUND: Functional deficits observed at long-term follow-up in surgically released clubfeet have led to the adoption of a nonoperative approach. Gait results reported at age 5 years found ankle motion was limited in clubfeet treated by posteromedial release (PMR), compared with those that required posterior release (PR) or remained nonoperative. The purpose of this study was to assess plantar pressures in clubfeet that required surgical correction by 5 years of age. METHODS: Pedobarograph data were collected at age 5 years on patients with clubfeet that underwent surgical correction due to residual deformity or recurrence. Plantar pressures were assessed by subdividing the foot into the medial/lateral hindfoot, midfoot, and forefoot regions. Variables included maximum force, contact area%, contact time% (CT%), the hindfoot-forefoot angle, and displacement of the center of pressure line. Surgical feet were divided into those that underwent an isolated PR versus PMR. A group of 72 clubfeet that remained nonoperative were matched by initial severity and used for comparison. RESULTS: Pedobarograph data from 53 patients (72 clubfeet; 25 PR and 47 PMR) showed minimal differences between the PR and PMR feet. Compared with the nonoperative group, both surgical groups had increased CT% in the medial hindfoot and medial midfoot regions. An increase in lateral hindfoot CT% was observed in the PMR group. In addition, CT% in the first metatarsal region in the PMR group was reduced compared with the nonoperative group. Lateralization is present across both surgical groups in the center of pressure line and hindfoot-forefoot angle. CONCLUSION: While there were minimal differences between surgical groups, patients who underwent PR exhibited pressure variables that were more comparable to the nonoperative group while the PMR group had greater deviations. LEVEL OF EVIDENCE: Level II-therapeutic.

Functional Outcomes Following Treatment for Clubfoot: Ten-Year Follow-up.

BACKGROUND: The purpose of this study was to assess function, at the age of 10 years, of children initially treated nonoperatively for clubfoot with either the Ponseti or French physiotherapy program and to compare outcomes in feet that had undergone only nonoperative treatment with those that required subsequent surgery. METHODS: Gait analysis, isokinetic ankle strength, parent-reported outcomes, and daily step activity data were collected when patients who had been treated for idiopathic clubfoot reached the age of 10 years. Patients who had undergone only nonoperative treatment were compared with those who subsequently underwent extra-articular surgery or intra-articular surgery (posterior release or posteromedial release). The clubfoot groups were compared with age-matched controls. RESULTS: Of 263 treated clubfeet in 175 patients, 148 had only been treated nonoperatively, 29 underwent extra-articular surgery, and 86 underwent intra-articular surgery (posterior release in 42 and posteromedial release in 44). Significant abnormalities were found in ankle kinetics and isokinetic ankle strength in the feet treated with intra-articular surgery compared with the nonoperatively treated feet (p < 0.017). Compared with controls (n = 40 feet), all groups showed reduced ankle plantar flexion during gait, resulting in a deficit of 9% to 14% for dynamic range of motion, 13% to 20% for ankle moment, and 13% to 23% for power (p < 0.013). Within the intra-articular group, feet that underwent posteromedial release had decreased plantar flexion strength (15%; p = 0.008), dorsiflexion strength (6%; p = 0.048), and parent-reported global function scores (p = 0.032) compared with the posterior release group. The patients with clubfoot took 10% fewer steps (p = 0.015) and had 11% less total ambulatory time (p = 0.001) than the controls. CONCLUSIONS: Examination of patients when they had reached the age of 10 years showed better ankle power and isokinetic strength for clubfeet treated without surgery compared with those that underwent intra-articular surgery for residual deformity or recurrence. Compared with controls, both nonoperatively and surgically treated clubfeet had significant limitations in ankle plantar flexion resulting in decreased range of motion, moment, and power. Gastrocnemius-soleus complex strength was decreased after both nonoperative and surgical treatment of clubfeet. Although activity was diminished in the clubfoot population, no differences in function were perceived by the patients' parents. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Plantar Pressures After Nonoperative Treatment for Clubfoot: Intermediate Follow-up at Age 5 Years.

INTRODUCTION: Worldwide, a nonoperative approach in the treatment of idiopathic clubfoot has been taken in an attempt to reduce the incidence of surgical outcomes. Although both the Ponseti casting (Ponseti) and the French physiotherapy (PT) methods have shown gait and pedobarograph differences at age 2 years, improved gait results have been reported by age 5 years. The purpose of this study was to assess plantar pressures in feet treated with the Ponseti versus the PT methods at this intermediate stage. METHODS: Clubfoot patients treated nonoperatively (Ponseti or PT) underwent pedobarograph data collection at age 5 years. The foot was subdivided into the medial/lateral hindfoot, midfoot, and forefoot regions. Variables included Peak Pressure, Maximum Force, Contact Area%, Contact Time%, Pressure Time Integral, the hindfoot-forefoot angle, and displacement of the center of pressure (COP) line. Twenty controls were used for comparison. RESULTS: Pedobarograph data from 164 patients (238 feet; 122 Ponseti and 116 PT) showed no significant differences between the Ponseti and the PT feet, except the PT feet had a significantly less medial movement of the COP than the Ponseti feet (P=0.0379). Compared with controls, both groups had decreased plantar pressures in the hindfoot and first metatarsal regions, whereas the midfoot and lateral forefoot experienced significant increases compared with controls. This lateralization was also reflected in the hindfoot-forefoot angle and the COP. CONCLUSIONS: Feet that remain nonoperative and avoid surgical intervention are considered a good clinical result. However, pedobarograph results indicate mild residual deformity in these feet despite clinically successful outcomes. LEVEL OF EVIDENCE: Level II-therapeutic.

A Longitudinal Review of Gait Following Treatment for Idiopathic Clubfoot: Gait Analysis at 2 and 5 Years of Age.

BACKGROUND: Initial correction following nonoperative (NonOp) treatment for idiopathic clubfoot has been reported in 95% of feet by age 2; however, by age 4, approximately one third of feet undergo surgery due to relapse. The purpose of this study was to assess the longitudinal effect of growth and surgical (Sx) intervention on gait following NonOp and Sx treatment for clubfoot. METHODS: Children with idiopathic clubfoot were seen for gait analysis at 2 and 5 years of age. Kinematic data were collected at both visits, and kinetic data were collected at age 5 years. Group comparisons were made between feet treated with the Ponseti casting technique (Ponseti) and the French physical therapy method (PT) and between feet treated nonoperatively and surgically. Comparisons were made between feet treated with a limited release or tendon transfer (fair) and those treated with a full posteromedial release (poor). The α was set to 0.05 for all statistical analyses. RESULTS: Gait data from 181 children with 276 idiopathic clubfeet were collected at both age 2 and 5 years. Each foot was initially treated with either the Ponseti (n=132) or PT (n=144) method but by the 5-year visit, 30 Ponseti and 61 PT feet required surgery. Gait outcomes showed limitations primarily in the Sx clubfeet. Normal ankle motion was only present in 17% of Ponseti and 21% of PT feet by age 5 following Sx management. Sx PT feet showed persistent intoeing at age 2 and 5. Within the Sx group, feet initially treated with PT had a clinically significant reduction in ankle power compared with those treated initially by the Ponseti method. Feet treated with posteromedial releases had significantly less ankle power than those treated with limited surgery or that remained NonOp at 5 years. CONCLUSIONS: This longitudinal study shows subtle changes between 2 and 5 years, and continues to support a NonOp approach in the treatment of clubfoot. LEVEL OF EVIDENCE: Level II-therapeutic.