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Relapse rates of clubfoot deformity after initial correction range between 19% and 68% regardless of treatment approach. Most studies focus on relapse before age 4. Little research has focused on late clubfoot relapse. The purpose of this study was to compare the gait characteristics of children with late clubfoot relapse (age ≥5 y) following treatment with the Ponseti method only compared with intra-articular and extra-articular surgeries.A retrospective review was conducted of all patients with idiopathic clubfoot ≥5 years old who underwent computerized gait analysis for clubfoot relapse between 2001 and 2021. Joint range of motion, muscle strength, gait kinematics, and kinetics were compared among 3 groups based on prior clubfoot treatment: (1) Ponseti casting, (2) Extra-articular (EA) surgery, and (3) Intra-articular (IA) surgery.Sixty-eight subjects (107 feet) were included (39 bilateral). Thirty-one percent of feet had been treated with Ponseti casting alone; 57% had IA surgery, and 12% had EA surgery. The average age when presenting with late relapse was 8.2 years, 9.0 years and 10.7 years for the Ponseti, and IA and EA groups, respectively. The IA group had greater passive dorsiflexion than the other 2 groups (P0.002), greater inversion weakness than the other 2 groups (P0.0001), greater dorsiflexion during the stance phase of gait compared with the Ponseti group (P=0.001), and lower maximum power production at push-off compared with the other 2 groups (P=0.009).Late relapse can occur after all types of clubfoot correction. Consistent with existing literature, patients who have undergone posteromedial release surgery have significantly greater plantarflexor weakness resulting in poorer plantarflexor moment and power production during gait.Level III, retrospective comparative study.

A threshold drainage area limits fluvial transmission of base-level fall and may be expressed in the form of a waterfall or a series of waterfalls, defined here as a knickzone. Knickzones on the west coast of Kaua‘i, Hawai‘i (USA), exhibit evidence of a threshold drainage area. Eighteen (18) of the 25 knickzones in our study area are located at the coast or a tributary junction, have a drainage area 1 km upstream from the coast or nearest tributary junction and range in drainage area from 1 to 5.5 km2. Both sets of knickzones limit incision relative to canyons without knickzones. Field observations show strong ‘a‘ā flows and dikes always crop out at the lip of knickzones, suggesting these resistant rocks and coarse sediment generated from them act to inhibit knickzone migration. A model incorporating flood records and channel conditions above knickzones shows thresholds of coarse sediment entrainment are never exceeded below 1 km2. Our results demonstrate knickzones on the west coast of Kaua‘i are enduring features explained by resistant lava flows and physical limits in bedrock incision.

The purpose of this study was to determine the differences in billable provider charges between single event multilevel surgery (SEMLS) based on comprehensive gait analysis and a staged surgical approach (SSA) without comprehensive gait analysis for the orthopedic treatment of ambulatory children with cerebral palsy (CP).The charges associated with nine common orthopedic surgical combinations (both unilateral and bilateral, soft tissue or soft tissue plus bony) for children with CP were determined and compared between SEMLS and SSA. The charges included surgical, anesthesia, operating room, recovery room, hospital stay, physical therapy, and, for SEMLS only, comprehensive computerized gait analysis.Total charges to complete each combination was higher for SSA than for SEMLS. The differential ranged from $10,247 to $75,069 with the percentage difference ranging from 20% to 47%. The mean difference was $43,606 (p = 0.0002). The dollar difference (r = 0.98, p 0.0001) and percentage difference (r = 0.79, p = 0.01) were both related to the total charge of the SEMLS surgery.Financial costs are lower for SEMLS vs. SSA for the treatment of multilevel gait issues in children with CP. The cost of gait analysis is much smaller than the cost differential between SEMLS and SSA. Although some patients who have SEMLS may need additional orthopedic surgery with associated costs, this is also possible for SSA. Therefore, due to the many benefits of SEMLS, which also include more informed treatment decision-making as well as reduced time away from school and work (for caregivers), SEMLS guided by gait analysis is recommended over SSA for the treatment of gait disorders in children with CP.

The purpose of our study is to evaluate athletic identity (AI) and mental health measures of youth and young adult athletes during the COVID-19 pandemic. This cross-sectional study recruited athletes aged 11–25 years from universities, high schools, and middle schools in California and New York. Participants were emailed a link to an anonymous, cross-sectional electronic survey. The measure included the athletic identity measurement scale (AIMS), the Patient Health Questionnaire-4 (PHQ-4), and demographic variables. Chi-square, Fisher’s Exact Test, and linear regression were used to examine the relationships between AI, symptoms of anxiety, and symptoms of depression by age, gender, and race. The survey was completed by 653 participants. AI was stratified by tertiary percentiles. The odds of positively scoring for symptoms of anxiety were 60% higher for participants in college compared with high school (OR: 1.60, 95% CI: [1.09, 2.35]). Conversely, the odds of scoring positively for symptoms of depression were 68% higher for participants in high school compared to college (OR: 1.68, 95% CI: [1.09, 2.59]). The odds of scoring positively for symptoms of depression were higher for athletes who scored as high AI, compared to those who scored as moderate (OR: 1.72, 95% CI: [1.11, 2.68]) or low (OR: 1.93, 95% CI: [1.20, 3.12]). The odds of scoring positively for symptoms of anxiety on the PHQ-4 were 3.2 times higher for participants who identified as female (OR: 3.19, 95% CI: [2.31, 4.41]), and the odds of scoring positively for symptoms of depression were 2.4 times higher for participants who identified as female (OR: 2.35, 95% CI: [1.56, 3.54]). Female athletes experienced symptoms of depression and anxiety at significantly higher rates than male athletes during the COVID-19 pandemic. High school students experienced fewer symptoms of anxiety, but greater symptoms of depression as compared to the collegiate group, while college students experienced greater odds of symptoms of anxiety. Athletes in the high AI group were more likely to report symptoms of depression than moderate or low identity groups. Female athletes reported lower AI than male athletes, but still had greater symptoms of anxiety and depression.

BackgroundSpina bifida, a neurological defect, can result in lower-limb muscle weakness. Altered ambulation and reduced musculoskeletal loading can yield decreased bone strength in individuals with spina bifida, yet individuals who remain ambulatory can exhibit normal bone outcomes.Research questionDuring walking, how do lower-limb joint kinematics, moments, and forces in independently ambulatory children with spina bifida differ from those of children with typical development?MethodsWe retrospectively analyzed data from 16 independently ambulatory children with spina bifida and 16 children with typical development and confirmed that bone strength was similar between the two groups. Plantar flexor muscle strength was measured by manual muscle testing, and 14 of the children with spina bifida wore activity monitors for one week. We estimated joint forces using motion capture data and musculoskeletal simulations. We used Statistical Parametric Mapping t-tests to compare lower-limb joint kinematic and kinetic waveforms between the groups with spina bifida and typical development. Within the group with spina bifida, we examined relationships between plantar flexor muscle strength and peak tibial forces by calculating Spearman correlations.ResultsActivity monitors from the children with spina bifida reported typical daily steps (9656 [SD 3095]). Despite slower walking speeds (p=0.004) and altered lower-body kinematics (pSignificanceHigh-functioning, independently ambulatory children with spina bifida exhibited near-typical bone strength and near-typical step counts and load magnitudes. Our results suggest that maintaining ambulation and muscle strength can promote bone health in this population.HighlightsGait analysis was performed in high-functioning children with spina bifidaOn average, these children had typical knee & ankle moments & forces during walkingWeak plantar flexor muscles were associated with increased tibial forces

Purpose Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP). Methods Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates. Results In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02). Conclusions ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°. Level of evidence III

The purpose of this study is to assess how Charcot-Marie-Tooth disease, a group of inherited peripheral neuropathies that result in distal weakness, affects walking velocity over time in comparison to age-matched controls. Comprehensive gait analysis of 57 children (mean age 12.0, SD 3.7 years) compared to 76 age-matched controls (mean age 10.1, SD 3.4 years) demonstrated slower walking velocity (p0.001) due to both shorter stride length (p0.001) and diminished cadence (p=0.01). There was higher walking velocity (p0.001), stride length (p=0.002) and cadence (p0.001) in patients with dorsiflexor strength ≥3 and higher walking velocity (p=0.001) and cadence (p=0.03) in patients plantar flexor strength ≥4. Analysis of Charcot-Marie-Tooth type 1 and type 2 subgroups showed that walking velocity increased significantly with age in controls (p=0.001) but did not increase in children with either subtype (p0.54). Stride length increased significantly with age in all groups (p0.001) but at a slower rate in type 1 and 2 compared to controls. These differences contributed to increasing deficits in walking velocity and stride length with age in type 1 and 2 in comparison to controls, with deficits appearing earlier in type 2. Since the slower walking velocity in children with Charcot-Marie-Tooth disease is primarily due to short stride length, treatments that enable improved stride length, such as plantar flexor strengthening and bracing, may improve walking velocity and associated gait function.

Parents are frequently cautioned by therapists, teachers, physicians, and online resources about potential negative effects of w-sitting in children (including hip dysplasia), despite lack of evidence. To examine relationships between w-sitting and hip dysplasia, a prospective cohort study was conducted of 104 patients (196 hips), aged 9.9 (standard deviation = 5.7) years, who underwent hip/pelvis radiography at a pediatric tertiary care center. Measures of hip dysplasia were taken from radiographs. Parents/patients completed a questionnaire regarding the patients’ sitting habits. Associations between hip dysplasia and w-sitting were analyzed statistically. About 48/104 parents/patients (46%) reported current or past w-sitting: 11/104 (11%) current, preferred position; 23/104 (22%) current, nonpreferred position, 14/104 (13%) w-sat in past, and 56/104 (54%) never w-sat. There was no difference in measures of hip dysplasia ( P > .12) or hip dysplasia frequency between w-sitters (9%) and non-w-sitters (10%; P = .81), or among w-sitting persistence groups ( P = .26). W-sitting in children is not associated with hip dysplasia.

Background This paper updates our 2011 systematic review on the clinical efficacy of three-dimensional instrumented gait analysis (3DGA). Research question What is the current evidence base pertaining to the clinical efficacy of 3DGA? Methods We identified English language articles published from September 2009 to October 2019 reporting primary research that used typical motion analysis laboratory methods to study human walking. Five gait laboratory experts classified articles according to the highest type of efficacy they addressed: type 1 (technical), 2 (diagnostic accuracy), 2b (outcome prediction), 3−4 (diagnostic thinking and treatment), 5 (patient outcome), 6 (societal). Articles classified into type 3−4 and higher were rated for quality using LEGEND. Results Of 2712 articles related to the efficacy of 3DGA, over 99% addressed technical (n = 313), diagnostic (n = 1466), or outcome prediction (n = 927) efficacy. Six type 3−4 studies showed that 3DGA changes treatment plans, increases clinicians’ confidence in their treatment decisions, and increases agreement among clinicians. Two type 5 articles based on a randomized controlled trial demonstrated that patient outcomes improved only when 3DGA data were available and its recommendations were followed. A population-based type 5 study found that the incidence of severe crouch gait dropped from 25% to 4% following practice changes including the addition of 3DGA. The strength of evidence was mainly 3b (lesser quality prospective cohort studies) but also included stronger studies (three level 2 controlled clinical trials). Significance Literature related to the clinical efficacy of 3DGA has grown substantially over the last decade. Thousands of articles contribute to continued improvement of data collection and interpretation, as well as understanding of gait pathology and treatment. A smaller number of studies clearly demonstrate the efficacy of 3DGA in changing and reinforcing treatment decisions, increasing clinicians’ confidence in treatment planning, and increasing agreement among clinicians, as well as the potential to improve patient outcomes.

Background Understanding movement variability is important to guide biomechanical assessment. Variability may change with age, and more repetitions of a movement need to be assessed when variability is high. Research question This study quantified the trial-to-trial (within subject) variability of three tasks commonly assessed during sports biomechanical testing: vertical drop jump, heel touch (single leg squat from step), and single leg hop. We hypothesized that pre-teen athletes would exhibit greater variability than more mature teenage athletes when performing all of these movements. Methods Fifty-five uninjured pediatric athletes ages 7–15 years performed 3 repetitions of vertical drop jump, heel touch, and single leg hop for distance tasks during 3D motion analysis testing. Trial-to-trial variability was assessed using the standard deviation (SD) and range (maximum–minimum) of clinically relevant kinematic and kinetic metrics among the multiple repetitions of each task performed by each participant. Variability was compared between age groups using 2-sided t-tests. Standard error of measurement (SEM) and minimum detectable difference (MDD) were also calculated for each variable of interest. Results For drop jump and heel touch, kinetic variability was similar between groups, but the younger group had greater kinematic variability. However, the older group was much more variable than the younger group during single leg hop landing, particularly in terms of kinetics and sagittal plane kinematics. Overall, kinematic variability had a median within-subject SD of 1−9°, median range of 2–17°, and 95th percentile for range of >15−20° for many of the variables examined. MDD was >10° for many kinematic variables, >0.2 Nm/kg for all frontal plane moments, >0.4 Nm/kg for most sagittal plane moments, and >0.5 W/kg for most energy absorption variables. Significance The high within-subject trial-to-trial variability in performing sports tasks suggests that multiple trials should be analyzed for a more complete and representative evaluation.

To examine associations between neurosegmental and functional level classifications in children with Spina Bifida, and determine which classification best reflects daily walking activity.A prospective correlational study was conducted. Children with Spina Bifida were given ratings for lesion level [X-ray and International Myelodysplasia Study Group (IMSG) level determined by muscle strength] and functional level [Hoffer ambulatory level and Dias functional classification of myelomeningocele (FCM), Functional Mobility Scale (FMS)]. Daily walking activity was measured with a StepWatch monitor. Data were analyzed using Spearman rank correlation.Sixty-one children were included, [56% male, average age 9.8 (SD 2.7) years]. The neurosegmental level classifications, X-ray lesion level and IMSG level showed little to no correlation with each other (The Dias FCM is comprehensive, including elements of neurosegmental level and function, and correlates well with walking activity. We recommend its use for classifying function in patients with Spina Bifida.Implications for rehabilitationFunctional classifications correlate better with daily walking activity than neurosegmental level classifications for patients with Spina Bifida.The Dias FCM includes neurosegmental and functional level elements, correlates well with daily activity, and is recommended for use in classifying Spina Bifida patients.Combined use of the FMS and activity monitoring is recommended for research and clinical assessment.

Objective To assess the relationship between real-world walking activity in children and adolescents with myelomeningocele (MMC) and gross measures of lower extremity strength, range of motion, demographics, and medical history. Design Prospective study. Setting Participants recruited in outpatient clinics; data collected in a hospital-based motion analysis laboratory and in the community. Participants Children and adolescents (N=52) with daily step count data available from a larger study of ambulatory children and adolescents with MMC. Interventions Not applicable. Main Outcome Measure Univariate and multivariate regression was used to assess which participant characteristics and clinical factors were related to average number of steps per day. Results Univariate analysis showed a lower number of steps per day correlated with older age, male sex, higher body mass index, higher lesion level, use of assistive devices for ambulation, history of shunt placement, more television (TV) watched per week, lower hip extension and abduction strength, knee flexion strength, and ankle dorsiflexion and plantarflexion strength, and decreased knee and hip range of motion. Only assistive device usage and hours of TV watched per week remained in the final multivariate model predicting number of steps per day. Conclusions Walking activity in children and adolescents with MMC was best predicted by assistive device use and amount of sedentary activity. Other predictors of walking activity from univariate analysis were related to assistive device use. This information can help tailor rehabilitation efforts and educate patients and families. Interventions targeting early prevention of strength loss and contractures may be important to retain or increase walking activity in children and adolescents with MMC.

Background : Out-toeing is common in children with cerebral palsy (CP), contributing to lever arm dysfunction and functional limitations. It is important to determine the cause(s) of out-toeing prior to treatment, whether surgical or non-surgical. Research Questions : What are the contributors to out-toeing in children with CP and do they differ between children with bilateral and unilateral involvement? Methods : The causes of out-toeing gait were determined retrospectively, with the use of computerized gait analysis, in 261 children with cerebral palsy (344 sides). The prevalence of various causes was calculated separately for children with bilateral and unilateral involvement, and compared statistically between groups using Fisher’s Exact analysis. Results : The most common cause of out-toeing was pes valgus in bilaterally involved subjects (71%) and pelvic external rotation (64%) in unilaterally involved subjects. Over half of the cases of out-toeing were due to multiple causes: 62% of the unilateral group and 53% of the bilateral group. In limbs with multiple causes of out-toeing in the bilateral group, pes valgus was one of the causes in 91% of limbs (146/161), and was most commonly combined with hip external rotation (27%), pelvic external rotation (22%), or external tibial torsion (20%). For the unilateral group with multiple causes of out-toeing, pelvic external rotation was one of the causes in 83% of limbs (20/24) and hip external rotation in 63% (15/24). Both were present (with or without additional causes) in 46% (11/24) of such limbs. Significance : The causes of out-toeing are multifactorial in over half of affected limbs of children with cerebral palsy. They also differ for children with bilateral and unilateral involvement. These findings should be carefully considered prior to non-surgical or surgical treatment of out-toeing gait in these patients, to allow all sites of pathology to be addressed, and to optimize outcomes.

A 52-year-old, ASA class II patient was scheduled for anterior cervical discectomy and fusion at the C3 - C4 level. During the surgery when the surgeon was placing retractors the patient developed an instant onset of asystole. This case review will discuss potential reasons for asystole during cervical spinal surgery, as well as anatomical considerations when confronted with asystole during surgical dissection and retraction. Many complications resulting from asystole have poor prognosis. This case study will review what was done in a timely manner to recognize and treat this life-threatening event.

The aim of this study was to identify the accuracy of the McMurray test in the adolescent and pediatric population.Retrospective case series.Tertiary care, institutional.Inclusion criteria included patients who presented with unilateral knee pain and were seen by pediatric sports medicine physicians. Patients were excluded if their knee pain was related to any underlying conditions. Three hundred patient charts were reviewed, and 183 patients (age range: 8-18 years, mean: 14 years; 74 male) met the inclusion criteria.Symptoms at initial visit (knee pain).Presence of a meniscal tear using the McMurray test.Eighty-four percent (160/191) of patients had a McMurray test documented as performed by the physician, and 17% (27/160) elucidated a positive response. Of 26 patients who had a positive McMurray and underwent magnetic resonance imaging (MRI), 16 (62%) showed a meniscal tear on their MRI. However, of the 87 patients who had a negative McMurray and still underwent MRI, 25 (29%) had a positive meniscal tear. The sensitivity, specificity, positive predictive value, and negative predictive value were 39%, 86%, 62%, and 71%, respectively.In a pediatric and adolescent population, the McMurray test was negative for 61% (23/38) of meniscal tears identified on MRI.Although the test can be a useful tool as a part of a thorough evaluation, combining it with mechanical symptoms, patient history and imaging may be more helpful to diagnose a meniscus tear.

Purpose Dynamic limb valgus, particularly high knee abduction moments, is a known risk factor for anterior cruciate ligament (ACL) injury and may result from poor static anatomic limb alignment, faulty biomechanics, or a combination of both. The purpose of this study was to assess the influence of static lower extremity anatomic alignment and dynamic kinematic/kinetic measures on knee abduction moments during sidestep cutting in adolescent athletes with recent ACL reconstruction. Methods This retrospective study included 50 adolescents with recent unilateral ACL reconstruction (18/50 female, mean age = 15.8 yr, 7.6 months postsurgery). Frontal plane hip-to-ankle imaging was used to measure mechanical axis deviation and tibial-femoral angle. Three-dimensional motion capture provided lower extremity kinematics and kinetics during quiet standing and during the loading phase (initial contact to peak knee flexion) of an anticipated 45° sidestep cut. Imaging, static motion capture, and dynamic motion capture measures were investigated as potential predictors of average dynamic knee abduction moment using correlation and backward stepwise linear regression. Results Dynamic knee abduction moment was best predicted by a combination of younger age and dynamic measures: trunk lean toward the planting limb, knee abduction and external rotation, and ankle inversion. Although static measures were correlated with dynamic knee abduction moment in univariate analysis, no static/anatomic variables entered the model once the dynamic measures were included. Conclusion Knee abduction moments during sidestep cutting were related to dynamic factors reflecting frontal and transverse plane motion. Static (anatomic) lower limb alignment did not influence knee abduction moments once these dynamic factors were considered. Knee abduction moments and ACL injury risk are therefore not dictated by anatomic alignment and can be altered through neuromuscular/biomechanical training.

BACKGROUND Previous study has shown that children with cerebral palsy (CP) functioning at Gross Motor Function Classification System (GMFCS) levels III and IV do not benefit from distal rectus femoris transfer (DRFT) due to lack of improvement in stance knee extension. The fate of knees in such subjects who do not undergo DRFT is unknown. The purpose of this study was to compare knee kinematic outcomes in patients with CP and stiff knee gait who underwent single-event multilevel surgery with and without DRFT. METHODS Preoperative and postoperative gait analysis data were retrospectively reviewed for ambulatory (GMFCS levels I to IV) patients with CP with crouch and stiff knee gait whom underwent single-event multilevel surgery, including hamstring lengthening either with DRFT (N=34) or without DRFT (N=40). Statistical analyses included t tests and χ tests, and multiple regression analysis was performed to adjust for covariates. Data were stratified by GMFCS level groups I/II and III/IV. RESULTS Improved maximum knee extension in stance was seen for both the DRFT (P=0.0002) and no DRFT groups (P≤0.0006) at GMFCS levels I/II, and the no DRFT group at GMFCS levels III/IV (P=0.02). Excessive stance knee flexion persisted for those at GMFCS level III/IV after DRFT. Maximum knee flexion in swing was maintained after DRFT, but significantly decreased in the no DRFT group (P

To determine prevalence, incidence and risk factors for foot pressure ulcers in ambulatory children with spina bifida.Retrospective cohort study of 72 ambulatory children (age range 0-23.9 years) with spina bifida treated at a pediatric tertiary care facility. Data on foot pressure ulcers were recorded and analyzed to determine prevalence, incidence and predictive factors.Foot pressure ulcers occurred in 50/143 limbs (35%) over 10.5 ± 3.5 years. Average incidence was 0.10 foot pressure ulcer incidents per person-year, and prevalence in years with complete follow-up was 8.8%. Prevalence was related to age [higher for ages 11-15 (17%), than ages 0-10 (5%) and 16+ years (7%),Foot pressure ulcers occur in nearly 1 out of 10 ambulatory children with spina bifida, most often in pre-teens or young teen-agers with foot deformities, who use braces. This information can help direct skin care education and prevention to those most vulnerable.Implications for RehabilitationFoot pressure ulcers occur in children and adolescents with spina bifida, most commonly in those aged 11-15 years, with foot deformities and who use braces.Ulcer development was unrelated to stiffness of foot deformity, body mass index, lesion or functional level, or presence of comorbidities such as Arnold-Chiari malformation, syringomyelia or shunted hydrocephalus.Skin care education and preventative measures should be provided to all patients, but with particular emphasis for those with these risk factors.

This study investigated asymmetry between lower extremities during the landing and takeoff phases of a vertical drop jump (VDJ) in adolescent athletes following anterior cruciate ligament reconstruction (ACLR) and examined if performance was affected by reducing jump height. Thirty-three athletes who underwent ACLR and were referred for 3D biomechanical assessment before returning to play (mean age 15.9, SD 1.3 years, 16/33 female, mean time since surgery 7.4, SD 1.2 months) completed the VDJ while kinematics and kinetics were collected using motion capture. Lower extremity symmetry was compared between phases using paired t-tests. Jump height was calculated to measure performance. Asymmetries in ankle inversion, ankle adduction, knee adduction, hip adduction, hip adduction moment, and hip rotation moment were observed in both phases. Asymmetry was also observed in both phases for sagittal moments and power integrals at the knee and ankle and total power integral, with the magnitude of asymmetry being smaller during takeoff for power absorption/generation. Jump height was related to power generation integrals during takeoff but not to the asymmetry of power generation. Since asymmetries are translated from landing through takeoff, rehabilitation should address both phases to decrease injury risk and maximize performance after return to play.

Background: Dynamic limb valgus and stiff landing are two known risk factors for anterior cruciate ligament (ACL) injury. These biomechanical risk factors can be evaluated through motion analysis testing. Hypothesis/Purpose: The purpose of this study was to compare risk scores for dynamic limb valgus and stiff landing between limbs with recent ACL reconstruction and uninjured (contralateral and control) limbs. Methods: Sports motion analysis data were reviewed for 177 pediatric patients after recent primary ACL reconstruction (ACLR) and 63 uninjured control subjects ages 8-17 years. 3D motion analysis data were collected while subjects performed the following sports-related tasks: heel touch from 6” or 9” step (depending if height >155 cm), drop jump from 41 cm height, lateral shuffle, forward-backwards deceleration, single leg hop, and 45° cutting. Each limb was scored for components of dynamic limb valgus (hip stability, pelvis stability, trunk stability) and stiff landing (shock absorption, hip strategy) based on the kinematic and kinetic measures in Table 1. Each scoring category was rated for each applicable task as adequate (2), borderline (1), or inadequate (0) based on values from the literature and laboratory norms. Percentage scores by scoring category were compared among reconstructed, contralateral, and control limbs using chi-square tests and ANOVA. Results: For the overall risk factors, stiff landing was worse in controls compared with both the reconstructed and contralateral limbs of patients (pConclusion: Post-operative ACLR patients demonstrated better biomechanics than controls on both the reconstructed and contralateral limbs in terms of avoiding stiff landing, particularly through better shock absorption. This may reflect training in proper biomechanics during physical therapy and rehabilitation. ACLR limbs were worse than control limbs only in trunk stability, which can be corrected with targeted training and awareness. Motion analysis is useful for identifying risky movement patterns so biomechanics can be corrected prior to return to play. [Table: see text][Figure: see text]

Background: Movement variability may affect injury assessment and may change as athletes mature. Hypothesis/Purpose: We hypothesized that pre-teen athletes would exhibit greater variability than teenage athletes when performing drop jump, heel touch, and single leg hop motions. Methods: 55 uninjured pediatric athletes were divided into pre-teen (age 7-12 years; n=29; 11 female) and teenage (age 13-15 years; n=26; 13 female) groups of similar size. All participants performed 2-3 repetitions per side of three sports related tasks: drop jump (41 cm), heel touch (single-leg squat from 15 cm or 23 cm step, depending on whether subject height 15° for many sagittal plane variables and >10° for many frontal and transverse plane variables in the younger group. In the singl- leg hop, the older group was much more variable than the younger group in the sagittal plane, particularly at the trunk, pelvis, and ankle (Figure 1.1 right). The younger group was still more variable than the older group at the trunk and pelvis in the transverse plane. Median within-subject variability ranged from 2-9° for SD and 3-17° for range of repeat measurements. Conclusion: There was substantial within-subject variability in performing sports related tasks for pediatric athletes of all ages. Variability was generally lower for older athletes, but was particularly high in the older group for sagittal plane trunk and pelvis motion during single-leg hop landing, which may reflect the need to adjust for less constrained positioning of a larger proximal mass. The high variability in performing sports tasks suggests that multiple trials should be analyzed for a more complete and representative evaluation. Figure 1.1. Variability (range of repeat measurements is shown) generally decreased with age during the drop jump and heel touch (left) but was much higher in the older group in the sagittal plane during single leg hop (right) Table 1.2. Median (5th percentile, 95th percentile) for standard deviation of within-subject measurements for pre-teen and teenage groups Drop Jump Heel Touch Single Leg Hop Age

Background: Previous research has identified deficient dual-task balance control at the time of return to play (RTP) and possible worsening after RTP in older adolescents/young adults with concussion. These findings have not been investigated in younger patients with concussion. Hypothesis/Purpose: We hypothesized that concussed adolescents would have slower walking speed and increased medial-lateral (ML) center of mass (COM) movement, which would normalize by the time of RTP but worsen after resuming activity. Methods: 13 adolescent concussion patients (7 male; age 10-17 years) were prospectively evaluated at their initial visit (IV) (mean 18, range 4-43 days post-concussion), at RTP clearance (mean 46, range 12-173 days post-concussion), and one month later (mean 26, range 20-41 days post-RTP) along with 11 controls (3 male) seen for similarly timed visits. Standing balance was assessed using range and root mean squared (RMS) COM motion in the anterior-posterior (AP) and ML directions during standing on both legs with eyes open while performing quiet standing, dual-task audio Stroop, side-to-side head turns, and side-to-side thumb tracking tasks. Dynamic balance was assessed using walking speed and COM ML range and velocity during walking alone and with side-to-side head turns and verbal fluency (reciting words starting with “F”) dual tasks. Patients were compared against controls using t-tests, and changes over time were evaluated using linear mixed-effects regression. Results: During standing, patients had higher COM ML RMS than controls at IV during head turns and higher COM AP range during thumb tracking. COM ML motion decreased from IV to RTP (head turns range -6.5mm, p=0.058; head turns RMS -16.8mm, p=0.002; thumb range 9.2mm, p=0.012) and increased from RTP to 1 month follow-up (head turns RMS +10.0mm, p=0.040; Stroop RMS +8.4mm, p=0.086). Patients walked slower than controls at IV during all tasks, and COM ML range was higher in patients vs. controls during verbal fluency at IV and RTP. Walking speed increased from IV to RTP during verbal fluency (+7.8cm/s, p=0.044), from RTP to post-RTP in single task walking (+6.1cm/s, p=0.041), and at each successive visit during head turns (+6.0cm/s and +6.5cm/s, pConclusion: Adolescent concussion patients had deficits in static and dynamic balance control at initial presentation. This tended to improve by RTP and only worsened post-RTP for dual-task ML control during standing, suggesting that current conservative treatment protocols are appropriate.

Supplemental material, Questionnaire_-_Supplemental_material for Hip Dysplasia Is Not More Common in W-Sitters by Susan A. Rethlefsen, Nicole M. Mueske, Alexander Nazareth, Oussama Abousamra, Tishya A. L. Wren, Robert M. Kay and Rachel Y. Goldstein in Clinical Pediatrics

Motion analysis offers objective insight into biomechanics, rehabilitation progress and return to sport readiness. This study examined changes in three-dimensional movement patterns during drop jump landing between early and late stages of rehabilitation in adolescent athletes following anterior cruciate ligament reconstruction (ACLR). Twenty-four athletes (58% female; mean age 15.4 years, SD 1.2) with unilateral ACLR underwent motion analysis testing 3-6 months and again 6-10 months post-operatively. Kinematics and kinetics were compared between visits and between limbs using repeated measures ANOVA. The operative side exhibited lower vertical ground reaction force, less energy absorption and lower sagittal external moments at the knee and ankle, and lower peak dorsiflexion angles compared with the non-operative side regardless of visit. Between visits, hip and knee flexion increased bilaterally, as well as hip flexion moments and energy absorption. During early rehabilitation following ACLR, adolescent athletes reduced flexion and loading of the knee and ankle on their operative limb. Motion and loading increased over time, particularly at the hip, but remained reduced at the knee and ankle 6-10 months post-operatively.

A cross-sectional comparison of vertebral morphology and lumbar lordosis (LL) in adolescents with and without spondylolysis.To test the hypothesis that in addition to LL, vertebral cross-sectional area (CSA) is also associated with spondylolysis.Recent data indicate that the CSA of the vertebral body is a determinant of LL, which has been shown to be associated with spondylolysis.Using magnetic resonance imaging, we compared the degree of LL from L1 to L5 and the CSA of the lumbar vertebrae in 35 adolescents (16 females and 19 males) with spondylolysis and 86 healthy controls (36 females and 50 males) of similar sex, age, height, and weight.There were no significant differences in age, height, weight, or vertebral height between subjects with and without spondylolysis, regardless of sex. In contrast, LL angle in spondylolysis patients was 57% and 51% greater in girls and boys with spondylolysis; 44.1 ± 10.4° versus 28.1 ± 9.8° and 34.8 ± 5.9° versus 23.0 ± 6.0° for girls and boys, respectively (both P's 0.0001). Additionally, values for vertebral CSA were on average, 8% and 10% smaller in females and males with spondylolysis; 7.6 ± 0.8 cmversus 8.3 ± 1.1 cm and 8.4 ± 1.6 versus 9.3 ± 1.6 for girls and boys, respectively (both P's ≤ 0.039). Multiple linear and logistic regression analyses indicated that the CSA of the vertebral body was negatively associated with LL angle and an independent predictor of the presence of spondylolysis. This was true regardless of whether girls and boys were analyzed together or independently, and whether LL angle was measured from L1 to L5 or S1.We provide evidence that patients with spondylolysis have increased LL and smaller vertebral CSA.4.

Recent observations indicate that the cross-sectional area (CSA) of vertebral bodies is on average 10% smaller in healthy newborn girls than in newborn boys, a striking difference that increases during infancy and puberty and is greatest by the time of sexual and skeletal maturity. The smaller CSA of female vertebrae is associated with greater spinal flexibility and could represent the human adaptation to fetal load in bipedal posture. Unfortunately, it also imparts a mechanical disadvantage that increases stress within the vertebrae for all physical activities. This review summarizes the potential endocrine, genetic, and environmental determinants of vertebral cross-sectional growth and current knowledge of the association between the small female vertebrae and greater risk for a broad array of spinal conditions across the lifespan.

Background: While multiple studies have shown clear benefits of autograft over allograft for anterior cruciate ligament reconstruction (ACLR) in young athletes, disagreement remains regarding the optimal autograft choice. Recovery from ACLR may be influenced by autograft type, which can include iliotibial band (IT), hamstring tendon (HT), quadriceps tendon (QT), or patellar tendon (PT) depending on skeletal maturity and surgeon preference. Hypothesis/Purpose: This study compared knee joint function among pediatric athletes with different types of ACLR autografts. We hypothesized that knee extensor function would recover faster for graft types that did not disrupt the knee extensor mechanism (i.e., IT and HT vs. PT and QT). Methods: This retrospective study examined 138 pediatric athletes (73 female; mean age 15.5, SD 2.2, range 8-21 years) who had undergone sports biomechanical testing in our motion analysis laboratory following recent unilateral ACLR (mean 7.7, range 3-18 months post-surgery). All reconstructions used autografts including 20 IT, 26 HT, 37 QT, and 55 PT. Lower extremity sagittal plane kinematics and kinetics were measured during vertical drop jump landing (41 cm height) and 45° cutting. Maximum knee flexion angles, internal knee extensor moments, and energy absorption during the landing phase (initial contact to peak knee flexion) of each movement were compared among graft types and sides (ACLR vs. contralateral) using linear mixed models with sex, age, and time since surgery as covariates. Results: Knee flexion was significantly lower on the operated vs. contralateral side for HT, QT, and PT during drop jump and for QT and PT during cutting (pConclusion: Young athletes with IT and HT autografts exhibit greater engagement of the knee extensors during dynamic loading than peers with PT or QT autografts in the 18 months following ACLR. This may be due to extensor mechanism donor site morbidity associated with PT and QT grafts. Tables/Figures: [Figure: see text]

A small vertebral cross-sectional area (CSA) imparts a mechanical disadvantage that escalates the risk for vertebral fractures in elderly populations. We examined whether a small vertebral CSA is also associated with a greater degree of vertebral wedging in children. Measurements of vertebral CSA, lumbar lordosis (LL) or thoracic scoliosis angle and vertebral wedging were obtained in 100 healthy adolescents (50 boys and 50 girls) and 25 girls with adolescent idiopathic scoliosis (AIS) using magnetic resonance imaging. Vertebral CSA of the lumbar vertebrae negatively correlated to the degree of posteroanterior vertebral wedging at L5 (r = -0.49; P

Study design Cross-sectional. Objective To examine the relationships between spine morphology, spine flexibility, and idiopathic scoliosis. Background Girls have a higher incidence of clinically significant scoliosis than boys, along with smaller vertebrae and greater flexibility. Based on biomechanical modeling, we hypothesized that smaller vertebral width relative to intervertebral disc (IVD) height would be associated with both greater lateral flexibility of the spine and with idiopathic scoliosis. Methods Magnetic resonance imaging was used to measure IVD height, vertebral width, and paraspinous musculature in 22 girls with mild and moderate idiopathic scoliosis and 29 girls without scoliosis ages 9–13 years. Clinical measurement of maximum lateral bending was also performed in the girls without scoliosis. A simple biomechanical model was used to estimate bending angle from the ratio of IVD height to vertebral half-width for L1–L4. The average ratio (Ravg) and calculated total bending angle (αtot) for L1–L4 were compared to the clinical measurements of lateral bending flexibility in the control group. These measures were also compared between the scoliosis and control groups. Results There was a significant positive relationship between clinical flexibility and both Ravg (p = .041) and αtot (p = .042) adjusting for skeletal age, height, body mass index, and paraspinous muscle area as covariates. The ratio was significantly higher (Ravg = 0.45 vs. 0.38, p Conclusion These results suggest that differences in spine morphology and corresponding changes in spine flexibility may be related to idiopathic scoliosis. If these relationships can be corroborated in larger prospective studies, these easily measured morphologic traits may contribute to a better understanding of the etiology of idiopathic scoliosis and an improved ability to predict scoliosis progression. Level of Evidence Level III.

INTRODUCTION Abnormal tibial torsion is a common pediatric problem, and there are many existing measurement methods. The purpose of this study was to compare three methods of measuring tibial torsion for its evaluation: computed tomography, physical examination, and motion capture. MATERIALS AND METHODS Twenty healthy children and 20 children with myelomeningocele underwent measures of tibial torsion bilaterally. Measurements were compared using correlation and Bland-Altman plots of the difference between measurements. RESULTS All three measurements were moderately correlated in controls (r≥0.49, p≤0.002) and in patients (r≥0.51, p≤0.001). In controls, the motion capture measurements were on average 2° more lateral than the clinical measurements whereas motion capture and clinical measurements were 13° and 15° more medial than CT measurements, respectively. Similarly for patients, motion capture measurements were on average 5° more medial than clinical measurements, and motion capture and clinical measurements were 26° and 22° more medial than CT measurements. CONCLUSIONS The approximate 20° difference between the clinical or motion capture measures and the CT measure suggests that clinical evaluation identifies different axes than those defined based on skeletal anatomy. Clinical or motion capture methods may be used in lieu of imaging methods for measuring tibial torsion with the knowledge that these methods provide less lateral measurements than measurements obtained using CT. This article is protected by copyright. All rights reserved.

Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

This study aimed to determine the effect of tibia marker placement on walking kinematics in children with pathological gait. Three-dimensional lower extremity gait data were collected using both a traditional tibia wand (protruding laterally from the distal shank) and a tibia crest marker on 25 children with pathological gait. Kinematic variables during walking and quiet standing were calculated using each marker and the “Plug-in Gait” implementation of the conventional gait model. For walking, average differences in kinematics between tibia markers ranged from 0.1° to 1.9° at the knee and ankle, except in the transverse plane where differences were 6.0° to 7.2°. No significant differences were found during quiet standing, indicating that differences in kinematics derive primarily from dynamic sources, which likely affect the tibia wand more than the tibia crest marker. These results suggest that the tibia crest marker can be used in place of the traditional tibia wand in clinical gait analysis.

BACKGROUND Dynamic limb valgus and poor shock absorption strategies have been implicated in anterior cruciate ligament (ACL) injuries. Additionally, biomechanics during over ground and double leg landing tasks have been shown to differ depending on sex and age/maturation. However, there is limited evidence evaluating the effect of age, body mass index (BMI) and sex on single leg landing strategies. METHODS 51 uninjured athletes (ages 7-15 years, mean 12.2, SD 2.3; 45% female) completed the single leg hop (SLH) for distance task. 3-D motion analysis using a 6 degree-of-freedom model was used to collect lower extremity kinematics and kinetics from initial foot contact to peak knee flexion of landing limb; for each limb the hop with the longest distance and appropriate landing (stuck for >2 seconds) was used for analysis. Using multivariate regression with standardized coefficients, the effects of age, BMI and sex on biomechanical variables of interest were assessed. RESULTS When considering dynamic valgus components, younger age was associated with higher knee valgus (ß=0.251; p=0.038) and hip abduction (ß=0.250; p=0.038) angles, higher BMI was associated with higher knee valgus angles (ß=0.262; p=0.028), and females tended to have higher hip abduction moments (ß=0.301; p=0.003), but a more abducted (ß=0.281; p=0.005) and internally rotated hip position (ß=0.359; p=0.003) along with higher internal rotation hip moments (ß=0.298; p=0.001) and with higher ankle inversion moments (ß=0.304; p=0.003). Although differences were observed, R2 values were low ranging from 0.191 (hip ab/adduction angles) to 0.053 (knee valgus moment). Sagittal plane components of shock absorption were partially explained by age, BMI and sex (R2 values range from 0.685 to 0.013; vertical ground reaction force (vGRF) in multiples of body weight, ankle dorsi/plantarflexion moment, respectively). Younger age was associated with higher vGRF (ß=-0.520; pCONCLUSION/SIGNIFICANCE Biomechanical risk factors for ACL injury during single leg hop landings are influenced by age, BMI and sex. Female sex and higher BMI are associated with dynamic limb valgus while younger age is associated with both dynamic limb valgus and poor shock absorption during single leg hop landings. These are important findings due to the known ACL injury risk in female athletes and the high re-tear rate in pediatric athletes. Identifying these biomechanical risk factors related to demographics and anthropometrics may provide objective direction needed to contribute to effective intervention strategies and eventual injury reduction in these high risk groups.