Acetabular "Fleck" Sign: Outcomes of Surgical Repair

BACKGROUND

Traumatic, posterior hip dislocations in the pediatric population are typically managed by closed reduction to achieve a concentric hip joint. The presence of an acetabular "fleck" sign, despite concentric reduction, has been shown to signify significant hip pathology. The purpose of this study was to evaluate the outcomes of open labral repair through a surgical hip dislocation (SHD) in a consecutive series of patients with an acetabular "fleck" sign associated with a traumatic hip dislocation/subluxation.

METHODS

A retrospective review of patients between 2008 and 2022 who presented to a single, level 1 pediatric trauma center with a traumatic posterior hip dislocation/subluxation was performed. Patients were included if they had an acetabular "fleck" sign on advanced imaging and underwent open labral repair through SHD. Medical records were reviewed for sex, age, laterality, mechanism of injury (MOI), and associated orthopaedic injuries. The modified Harris hip score (mHHS) was utilized as the primary clinical outcomes measure. Patients were assessed for the presence of heterotopic ossification (HO) and complications, including implant issues, infection, avascular necrosis (AVN), and post-traumatic dysplasia.

RESULTS

Twenty-nine patients (23 male, average age: 13.0±2.7 y; range: 5.2 to 17.3) were identified. Eighteen injuries were sports related, 9 caused by motor vehicle accidents, and 1 pedestrian struck. All patients were found to have an acetabular "fleck" sign on CT (26 patients) or MRI (5 patients). Associated injuries included: femoral head fracture (n=6), pelvic ring injury (n=3), ipsilateral femur fracture (n=2), and ipsilateral PCL avulsion (n=1). At the latest follow-up (2.2±1.4 y), all patients had returned to preinjury activity/sport. Three patients developed asymptomatic, grade 1 HO in the greater trochanter region. There was no incidence of AVN. One patient developed post-traumatic acetabular dysplasia due to early triradiate closure. mHHS scores showed excellent outcomes (n=21, 94.9±7.4, range: 81 to 100.1).

CONCLUSIONS

The acetabular "fleck" sign indicates a consistent pattern of osteochondral avulsion of the posterior/superior labrum. Restoring native hip anatomy and stability is likely to improve outcomes. SHD with open labral repair in these patients produces excellent clinical outcomes, with no reported cases of AVN.

LEVEL OF EVIDENCE

Level IV-therapeutic.

COVID-19 Stay-at-home mandates impacts daily ambulatory bout intensity and duration in elementary school-aged children: A wearable sensor based analysis

INTRODUCTION

SARS COVID-19 pandemic resulted in major changes to how daily life was conducted. Health officials instituted policies to decelerate the spread of the virus, resulting in changes in physical activity patterns of school-aged children. The aim of this study was to utilize a wearable activity monitor to assess ambulatory activity in elementary-school aged children in their home environment during a COVID-19 Stay-at-Home mandate.

METHODS

This institutional review board approved research study was performed between April 3rd - May 1st of 2020 during which health officials issued several stay-at-home (shelter-in-place) orders. Participant recruitment was conducted using a convenience sample of 38 typically developing children. Participants wore a StepWatch Activity Monitor for one week and data were downloaded and analyzed to assess global ambulatory activity measures along with ambulatory bout intensity/duration. For comparison purposes, SAM data collected before the pandemic, of a group of 27 age-matched children from the same region of the United States, was included. Statistical analyses were performed comparing SAM variables between children abiding by a stay-at-home mandate (Stay-at-Home) versus the Historical cohort (alpha=0.05).

RESULTS

Stay-at-Home cohort took on average 3737 fewer daily total steps compared to the Historical cohort (p<0.001). Daily Total Ambulatory Time (TAT), across all days was significantly lower in the Stay-at-Home cohort compared to the Historical cohort (mean difference: 81.9 minutes, p=0.001). The Stay-at-Home cohort spent a significantly higher percentage of TAT in Easy intensity ambulatory activity (mean difference: 2%, p<0.001) and therefore a significantly lower percentage of TAT in Moderate+ intensity (mean difference: 2%, p<0.001).

CONCLUSIONS

The stay-at-home mandates resulted in lower PA levels in elementary school-aged children, beyond global measures to also bout intensity/duration. It appears that in-person school is a major contributor to achieving higher levels of PA and our study provides additional data for policymakers to consider for future decisions.

A 2D video-based assessment is associated with 3D biomechanical contributors to dynamic knee valgus in the coronal plane

Introduction

Adolescent athletes involved in sports that involve cutting and landing maneuvers have an increased risk of anterior cruciate ligament (ACL) tears, highlighting the importance of identifying risky movement patterns such as dynamic knee valgus (DKV). Qualitative movement screenings have explored two-dimensional (2D) scoring criteria for DKV, however, there remains limited data on the validity of these screening tools. Determining a 2D scoring criterion for DKV that closely aligns with three-dimensional (3D) biomechanical measures will allow for the identification of poor knee position in adolescent athletes on a broad scale. The purpose of this study was to establish a 2D scoring criterion that corresponds to 3D biomechanical measures of DKV.

Methods

A total of 41 adolescent female club volleyball athletes performed a three-task movement screen consisting of a single-leg squat (SLS), single-leg drop landing (SLDL), and double-leg vertical jump (DLVJ). A single rater scored 2D videos of each task using four criteria for poor knee position. A motion capture system was used to calculate 3D joint angles, including pelvic obliquity, hip adduction, knee abduction, ankle eversion, and foot progression angle. Receiver operating characteristic curves were created for each 2D scoring criterion to determine cut points for the presence of movement faults, and areas under the curve (AUC) were computed to describe the accuracy of each 2D criterion compared to 3D biomechanical data.

Results

3D measures indicated knee abduction angles between 2.4°-4.6° (SD 4.1°-4.3°) at the time point when the center of the knee joint was most medial during the three tasks. AUCs were between 0.62 and 0.93 across scoring items. The MEDIAL scoring item, defined as the knee joint positioned inside the medial border of the shoe, demonstrated the greatest association to components of DKV, with AUCs ranging from 0.67 to 0.93.

Conclusion

The MEDIAL scoring criterion demonstrated the best performance in distinguishing components of DKV, specifically pelvic obliquity, hip adduction, ankle eversion, and foot progression. Along with the previously published scoring definitions for trunk-specific risk factors, the authors suggest that the MEDIAL criterion may be the most indicative of DKV, given an association with 3D biomechanical risk factors.

Pre-operative gait kinematics and kinetics do not change following surgery in adolescent patients with femoroacetabular impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a condition where the femoral head-neck junction collides with the acetabulum. Open or arthroscopic treatment of FAI aims to increase hip motion while reducing impingement during passive or dynamic movements.

RESEARCH QUESTION

What are the biomechanical characteristics of the hip and pelvis in adolescents and young adults diagnosed with FAI syndrome 1) pre-operatively compared to controls and 2) pre- to post-operatively?

METHODS

43 patients with FAI and 43 controls were included in the study. All patients with FAI had cam deformities and underwent unilateral hip preservation surgery (either open or arthroscopic). Pre- and post-operative imaging, patient-reported outcomes, and gait analysis were performed. Joint angles and internal joint moments were evaluated with an emphasis on the pelvis and hip. A comparative analysis was conducted to evaluate the gait patterns before and after surgical treatment, as well as to compare pre-operative gait patterns to a control group.

RESULTS

43 patients with FAI (28 female, 16.5 ± 1.5 yrs) and 43 controls (28 female, 16.0 ± 1.5 yrs) were included. Pre-operative patients with FAI had decreased stride length and walking speed compared to controls, with no significant change following surgery. There were no differences in sagittal and coronal plane hip and pelvis kinematics comparing pre- to post-operative and pre-operative to controls. Pre-operatively, differences in internal hip rotation angle (pre: 3.3˚, post: 3.9˚, controls: 7.7˚) and hip extensor moment (pre: 0.121, post: 0.090, controls: 0.334 Nm/kg) were observed compared to controls with no significant changes observed following surgery.

SIGNIFICANCE

Compensatory movement strategies in pelvic and hip motion are evident during gait in patients with FAI, particularly in the sagittal and transverse planes. These strategies remained consistent two years post-surgery. While surgery improved radiographic measures and patient-reported outcomes, gait did not elicit biomechanical changes following surgical treatment.

How Much Bullying and Discrimination Are Reported by Sexual and Gender Minorities in Orthopaedics?

BACKGROUND

Discriminatory practices against minority populations are prominent, especially in the workplace. In particular, lesbian, gay, bisexual, transgender, and queer or questioning (LGBTQ+) individuals experience several barriers and stressors more often than individuals who do not identify as LGBTQ+. Mistreatment is common among these individuals in their personal and professional lives. However, representation and perceptions of discrimination and bullying among attendings, residents, medical students, and other professionals who identify as LGBTQ+ and are "out" (openly acknowledging and expressing one's sexual orientation or gender identity) is seldom studied in orthopaedic surgery.

QUESTIONS/PURPOSES

(1) How often are orthopaedic trainees and professionals who identify as LGBTQ+ out in their workplaces? (2) What proportion of these individuals report experiencing discrimination, bullying, or differential treatment? (3) Is there regional variation in these reported experiences of bullying and discriminatory behaviors by orthopaedic trainees and professionals in the LGBTQ+ community?

METHODS

Individuals registering for Pride Ortho, a community of LGBTQ+ individuals and their allies established in 2021 to provide mentorship, networking, and a sense of community among its members, completed an internet-based survey developed by organization leadership. A total of 156 individuals registering for the Pride Ortho community were eligible to participate in the internet-based survey. In all, 92% (144 of 156) fully completed the survey, 6% (10 of 156) partially completed it, and 1% (2 of 156) did not complete any part of the survey. Most respondents (64% [100 of 156]) identified as being LGBTQ+, with 77 members at the attending level of their careers. More than half of LGBTQ+ members (56% [56 of 100]) identified as cisgender women (individuals who identify as women and who were born female). Demographic information was privately collected and deidentified, and included sex assigned at birth, gender expression or identity (the social constructed role that an individual chooses to inhabit, regardless of that individual's assigned sex at birth), sexual orientation, self-identified race, location, level of training, and orthopaedic subspecialty.

RESULTS

Ninety-four percent (94 of 100) of LGBTQ+ respondents reported being out at their workplace, with nearly one-third of respondents indicating they were only partially out. Most (74% [74 of 100]) respondents reported either "yes" or "maybe" to perceived experiences of bullying, discrimination, or being treated differently. All individuals who partially completed the survey were straight or heterosexual and did not answer or answered "not applicable" to being out in their workplace. These individuals also all answered "no" to experiencing bullying, discrimination, or being treated differently. There was no geographic variation in reported experiences of bullying and discriminatory behaviors by orthopaedic trainees and professionals.

CONCLUSION

Most LGBTQ+ orthopaedic trainees and professionals are out in their workplaces, although they report experiencing discrimination and bullying more than do non-LGBTQ+ individuals. Bullying and discrimination can deter individuals from beginning and completing their training in orthopaedic surgery. We recommend that orthopaedic institutions not only enforce existing antidiscrimination legal mandates but also increase the visibility of LGBTQ+ faculty and residents. This effort should include the implementation of diversity and sensitivity training programs, strengthened by a structured process of monitoring, reporting, and integrating feedback from all members in the workplace to continuously refine policy adherence and identify the root cause of the reported perceptions of bullying and discrimination.

CLINICAL RELEVANCE

To deepen our understanding of the experiences faced by sexual and gender minorities in orthopaedic surgery settings, it is crucial to quantify reports of perceived bullying and discrimination. Addressing these issues is key to creating a more diverse and empathetic workforce within orthopaedic institutions, which in turn can lead to improved patient care and a better work environment. Recognizing and understanding the specific contexts of these experiences is an essential starting point for developing a truly inclusive environment for both trainees and attending physicians.

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.

Concurrent Validity of The Expanded Cutting Alignment Scoring Tool (E-CAST)

Background

The Expanded Cutting Alignment Scoring Tool (E-CAST) has been previously shown to be reliable when assessing lower extremity alignment during a 45-degree sidestep cut, however, the validity of this tool remains unknown. The purpose of this study was to assess the concurrent validity of the E-CAST by comparing visually identified movement errors from two-dimensional (2D) video with three-dimensional (3D) biomechanical variables collected using motion capture.

Study Design

Cross Sectional.

Methods

Sixty female athletes (age 14.1 ± 1.5 years) who regularly participated in cutting/pivoting sports performed a sidestep cut with 2D video and 3D motion capture simultaneously recording. One clinician scored the 2D videos for each limb using the E-CAST criteria. Joint angles and moments captured in 3D were computed for the trunk and knee. Receiver operating characteristic (ROC) curve analyses were performed to determine the accuracy of each E-CAST item and to provide cut-off points for risk factor identification.

Results

ROC analyses identified a cut-off point for all biomechanical variables with sensitivity and specificity ranging from 70-85% and 55-89%, respectively. Across items, the area under the curve ranged from 0.67 to 0.91.

Conclusion

The E-CAST performed with acceptable to outstanding area under the curve values for all variables except static knee valgus.

Level of evidence

3b.

Potential limitations of measuring ambulatory activity of part-time wheelchair users: a comparative study of two research grade activity monitors

Objective.Research grade activity monitors such as the StepWatch Activity Monitor (SAM) and Actigraph have been shown to be highly accurate for the assessment of ambulatory activity, but some individuals function in the community using a combination of both walking and wheelchair activity. The purpose of this study was to assess the accuracy of the SAM and Actigraph at not detecting ambulatory activity, during wheelchair activities at two intensity levels.Approach.Two independent cohorts were tested while simultaneously wearing a SAM and Actigraph on the ankle. Group 1 consisted of twelve adults performing a six-minute push test (6MPT). Group 2 were eighteen members of an adolescent wheelchair basketball team tested during a scrimmage/practice and regional tournament. Visual observation was used to confirm the number of ambulatory steps taken during testing was zero.Main results.The average number of 'steps' detected during a 6MPT was 19 ± 25 (range: 0-85) with the Actigraph. No 'steps' were detected using the SAM in Group 1. In Group 2, the average 'step' count during basketball practice was 1421 ± 750 (range: 612-2798) using the Actigraph and 1363 ± 1238 (range: 84-3462) using the SAM, and correlated with playing time, despite the leg/ankle being strapped down. Similar findings were observed during the wheelchair basketball regional tournament.Significance.Caution should be heeded when utilizing these activity monitors in individuals with disabilities who participate in wheelchair sports. Additional written activity logs should be used to exclude periods of time during which high acceleration wheelchair sporting activity occurs, or study participants should be fully educated in removing the activity monitors during non-ambulatory wheelchair sports.

Orthopaedic Manifestations of Thanatophoric Dwarfism: A Case Report

CASE

We report the rare case of a 3-year-old male patient with thanatophoric dwarfism, a fatal skeletal dysplasia that arises from an autosomal dominant mutation in the fibroblast growth factor receptor 3 gene. The role of the orthopaedic surgeon in the in the management of this disease is discussed.

CONCLUSION

We advocate for the close monitoring of disease progression by the orthopaedic surgery team and offer a potential surgical intervention that may help prevent cardiorespiratory demise.

No Difference in Two-Dimensional Kinematic Assessment of a 45-Degree Sidestep Cut Compared to Qualitative Assessment

Background and Purpose

The Expanded Cutting Alignment Scoring Tool (E-CAST) is a two-dimensional qualitative scoring system that has demonstrated moderate inter-rater and good intra-rater reliability for the assessment of trunk and lower extremity alignment during a 45-degree sidestep cut. The primary purpose of this study was to examine the reliability of the quantitative version of the E-CAST among physical therapists and to compare the reliability of the quantitative E-CAST to the original qualitative E-CAST. The hypothesis was that the quantitative version of the E-CAST would demonstrate greater inter-rater and intra-rater reliability compared to the qualitative E-CAST.

Study Design

Observational cohort, repeated measures reliability study.

Methods

Twenty-five healthy female athletes (age 13.8±1.4 years) performed three sidestep cuts with two-dimensional video capturing frontal and sagittal views. Two physical therapist raters independently scored a single trial using both views on two separate occasions. Based on the E-CAST criteria, select kinematic measurements were extracted using a motion analysis phone application. Intraclass correlation coefficients and 95% confident intervals were calculated for the total score, and kappa coefficients were calculated per kinematic variable. Correlations were converted to z-scores and compared to the six original criteria for significance (α<0.05).

Results

Cumulative intra- and inter-rater reliability were both good (ICC=0.821, 95% CI 0.687-0.898 and ICC=0.752, 95% CI 0.565-0.859). Cumulative intra-rater kappa coefficients ranged from moderate to almost perfect, and cumulative inter-rater kappa coefficients ranged from slight to good. No significant differences were observed between the quantitative and qualitative criteria for either inter- or intra-rater reliability (Z_obs(intra)= -0.38, p=0.352 and Z_obs(inter)= -0.30, p=0.382).

Conclusion

The quantitative E-CAST is a reliable tool to assess trunk and lower extremity alignment during a 45-degree sidestep cut. No significant differences were observed in reliability of the quantitative versus qualitative assessment.

Level of evidence

3b.

Normative dataset selection affects gait profile scores of children with cerebral palsy

INTRODUCTION

The Gait Profile Score (GPS) requires a comparative dataset, to identify altered mechanics in persons with a gait abnormality. This gait index has been shown to be useful for identifying gait pathology prior to the assessment of treatment outcomes. Though studies have shown differences in kinematic normative datasets between different testing sites, there is limited information available on the changes in GPS score based on normative dataset selection. The aim of this study was to quantify the influence of normative reference data from two institutions, on the GPS and Gait Variable Scores (GVS), calculated on the same group of patients with Cerebral Palsy.

METHODS

Seventy patients (Avg. age: 12.1 ± 2.9) diagnosed with CP underwent gait analysis during walking at a self-selected speed at Scottish Rite for Children (SRC). GPS and GVS scores were determined using normative kinematic data at a self-selected speed from, 83 typically developing children ages 4-17 from Gillette, and the same age range of children from SRC's normative dataset. Average normalized speed was compared between institutions. Signed rank tests were performed on the GPS and GVS scores using each institution's dataset. Spearman's correlations between scores using SRC and Gillette were determined within GMFCS level.

RESULTS

Normalized speed was comparable between each institution's datasets. Within each GMFCS level, significant differences when using SRC vs. Gillette were found in most scores (p < 0.05). Scores were moderately to strongly correlated within each GMFCS level (range ρ = 0.448-0.998).

CONCLUSIONS

Significant statistical differences were found in GPS and GVS scores but were within the range of previously reported variation across multiple sites. Caution and consideration may need to be taken when reporting GPS and GVS scores that are calculated utilizing different normative datasets as these scores may not be equivalent.

Targeted Muscle Reinnervation for Limb Amputation to Avoid Neuroma and Phantom Limb Pain in Patients Treated at a Pediatric Hospital

Amputees frequently experience chronic neuroma-related residual limb and phantom limb pain (PLP). Targeted muscle reinnervation (TMR) transfers transected nerves to nearby motor nerves to promote healing and prevent neuroma formation and PLP. The purpose of this study was to report outcomes of TMR in a series of children and young adults treated at a pediatric hospital.

Methods

Patients undergoing major limb amputation with TMR were included with minimum one year follow-up and completed questionnaires. Primary clinical outcomes included incidence of symptomatic neuromas, PLP, residual limb pain, narcotic use, and neuromodulator use. A follow-up phone survey was conducted assessing five pediatric Patient Reported Outcomes Measurement Information System (PROMIS) metrics adapted to assess residual limb and PLP.

Results

Nine patients (seven male and two female patients, avg. age = 16.83 ± 7.16 years) were eligible. Average time between surgery and phone follow-up was 21.3 ± 9.8 months. Average PROMIS Pediatric t-scores for measures of pain behavior, interference, quality-affective, and quality-sensory for both PLP and residual limb pain were nearly 1 standard deviation lower than the United States general pediatric population. One patient developed a symptomatic neuroma 1 year after surgery.

Conclusions

Compared with an adult patient sample reported by Valerio et al, our TMR patients at Nationwide Children's Hospital (NCH) showed similar PLP PROMIS t-scores in pain behavior (50.1 versus 43.9) and pain interference (40.7 versus 45.6). Both pediatric and adult populations had similar residual limb pain including PROMIS pain behavior (36.7 adult versus 38.6 pediatric) and pain interference (40.7 adult versus 42.7 pediatric). TMR at the time of amputation is feasible, safe, and should be considered in the pediatric population.

Age-, Sex-, and Graft-Specific Reference Values From 783 Adolescent Patients at 5 to 7 Months After ACL Reconstruction: IKDC, Pedi-IKDC, KOOS, ACL-RSI, Single-Leg Hop, and Thigh Strength

OBJECTIVE: To describe age-, sex-, and graft source-specific reference values for patient-reported, physical function, and strength outcome measures in adolescents at 5 to 7 months after anterior cruciate ligament reconstruction. DESIGN: Cross-sectional study. METHODS: Data were collected at 3 universities and 2 children's hospitals. The participants completed at least one of the International Knee Documentation Committee (IKDC) Subjective Evaluation Form, Pediatric IKDC (Pedi-IKDC), Knee Injury and Osteoarthritis Outcomes Score (KOOS), and Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale. Participants also completed single-leg hop tests and/or isokinetic quadriceps and hamstrings strength assessments (at 60°/s). Reference values were summarized using descriptive statistics and stratified for age, sex, and graft source. RESULTS: Reference values were reported for common patient-reported outcomes and measures of physical function and strength from 783 participants (56% females, age = 16. 4 ± 2.0 years) who were in early adolescence (12-14 years, N = 183, 52% females), middle adolescence (15-17 years, N = 456, 58% females), or late adolescence (18-20 years, N = 144, 55% females). Three hundred seventy-nine participants (48.4%) received a bone-patellar tendon-bone autograft, 292 participants (37.3%) received hamstring tendon autograft, and 112 participants (14.3%) received autograft or allograft from an alternative source. CONCLUSION: Reference values for common patient-reported outcomes and measures of physical function and strength differed depending on a patient's age, sex, and graft source. Using patient-specific reference values, in addition to previously described age-appropriate cutoff values, may help clinicians monitor and progress patients through rehabilitation and return to physical activity after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 2023;53(4):1-8. Epub: 23 January 2023. doi:10.2519/jospt.2023.11389.

Functional Implications of Flat-Topped Talus Following Treatment of Idiopathic Clubfoot Deformity

BACKGROUND

Though flatness of the talar dome (TD) is a potential consequence of operative and nonoperative clubfoot management, the functional impact of this deformity is not well understood. This study analyzes the relationship between TD morphology and ankle function at skeletal maturity in patients treated for idiopathic clubfoot during infancy.

METHODS

33 skeletally mature patients (average age 17.9 years) with 48 idiopathic clubfeet were identified. Weightbearing radiographs, gait analysis, and patient-reported outcomes using the Pediatric Orthopaedic Data Collection Instrument (PODCI) were obtained. Radius of curvature (ROC) of the TD and tibial plafond were measured along with other parameters of talar and calcaneal morphology. All measurements were correlated to PODCI scores and gait analysis data.

RESULTS

Patients demonstrated marked variability in ROC of the TD (mean 30.8 mm, SD 13.6 mm), TD radius to talar length (R/L) ratio (mean 0.56, SD 0.28), opening angle of the TD (alpha angle) (mean 89.6°, SD 28.4°), and tibiotalar incongruity index (mean 0.18, SD 0.16). Increased tibiotalar incongruity index correlated with decreased maximum plantar flexion (r = ‒0.325, P = .02). A less acute alpha angle of the talar dome correlated with increased maximum ankle power generation (r = 0.321, P = .03) as did increased length of the talar neck (r = 0.358, P = .013). Increased tibiotalar incongruity index correlated negatively with PODCI global function domain scores (r = ‒0.490, P = .04; r = ‒0.381, P = .03, respectively), whereas length of the talar body correlated with higher global function scores (r = 0.376, P = .03) and lower pain scores (r = 0.350, P = .046).

CONCLUSION

At skeletal maturity, flattening of the talar dome and tibiotalar incongruity on plain radiographs correlate modestly with gait changes, whereas tibiotalar incongruity and length of the talar body, not flatness of the talar dome, correlate with decreased patient-reported outcome scores.

LEVEL OF EVIDENCE

Level III, prognostic.

Advancing biomechanics laboratories capabilities: A proposed framework for in-house technology development

BACKGROUND

Technological advancements have generated more opportunities to develop/distribute custom data analysis codes (e.g., automated events, biomechanical models, etc.). Industry standards for the code development process is regularly modeled to ensure product quality and usability. Procedural project management improves efficiency of the code development process by monitoring project planning, duration, analysis, success, and maintenance. The purpose of this study was to outline in the form of guidance to research labs, a framework that standardizes the development, management, testing, and documentation of various types of data analysis codes, utilized in the motion analysis laboratory setting.

METHODS

This brief report outlines the workflow, briefly highlights its success a year after implementation, and provides a framework that can be adopted across laboratories of different sizes and those involved in multi-center collaborative studies. Specifically, the workflow outlined is initiated when a requestor has identified the need for a custom data analysis code. The workflow is complete and the code is released once the results of testing performed by a non-affiliated user, verifies that the code project workflow was followed appropriately, confirms a standard operating procedure has been finalized, and ensures the requestor and additional end-users are satisfied with the final product.

FINDINGS

Guidance documents and optimization of workflows are imperative for motion analysis laboratories managing numerous coding projects.

INTERPRETATION

Implementation of the proposed framework is an effective approach to reduce workload, by minimizing redundancies, maximizing on the research team's expertise and promotes collaborative input which in turn allows for feedback along the process.

Inclusive community playgrounds benefit typically developing children: An objective analysis of physical activity

Purpose

Limited research is available on the physical activity levels of children while playing on an inclusive playground, specifically designed to accommodate children with physical disabilities. The aims of this study were to objectively measure ambulatory activity and heart rate (HR) of children during unstructured play on an inclusive community playground.

Methods

Typically developing children at least 4 years of age were recruited to play freely upon entering the playground. Participants wore a StepWatch4 Activity Monitor and a Polar V800 Sport Watch. Ambulatory measures included total steps, percentage of recommended steps, total ambulatory time (TAT), bout intensity levels/duration periods. Time spent in HR zones and moderate-to-vigorous physical activity (MVPA) was determined.

Results

95 children (48 males; Avg. age: 7 ± 2 years.) were included in this study. Children played for 31.8 ± 14.7 min., were ambulatory for 25.9 ± 12.0 min., took 1826 ± 824 steps, and accumulated 17 ± 8% of the recommended daily step count. Ambulatory bout intensity was predominantly lower intensity and bout durations varied in length. 99% of the play time was spent at a moderate HR or higher. Significant correlations were found between ambulatory and HR measures (ρ range from 0.23 to 0.99, p < 0.05), and 7-10 yo children spent a significantly higher percentage of TAT at higher intensity ambulation (p < 0.05).

Conclusions

Typically developing children can achieve moderate or higher intensity exercise and HR on an inclusive playground. Both typically developing children and those with disabilities, would benefit from a setting where they can interact and participate in parallel play with their peers.

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.

Disparity in Built Environment and Its Impacts on Youths' Physical Activity Behaviors During COVID-19 Pandemic Restrictions

Objectives

Guided by the social ecological model, this study aimed to examine the relations of built environments (i.e., walking/cycling infrastructure, recreation facilities, neighborhood safety/crime), youth’s transition abilities, and changes of youth’s physical activity (PA) and play behaviors due to COVID-19-based restrictions. Ethnic and socioeconomic status (SES) disparities were also examined on studies variables during the COVID-19 restrictions.

Method

A cross-sectional research design was used to assess an anonymous online survey completed by US parents/guardians. The final sample had 1324 children and adolescents (Mean_age = 9.75; SD = 3.95; 51.3% girls), and 35.5% the families were of upper socioeconomic class (income > $150,000). Parents reported the perceived built environment and neighborhood safety, child’s PA and play behaviors during COVID-19 pandemic shelter-in-place restrictions.

Results

Youths who had access to safe built environment were more active and played more outdoor/indoor (p < .01). It was found playing behavior in yard and neighborhood were significantly increased, but community-based play behavior was significantly reduced during COVID-19 restrictions. The SEM analysis (χ²/df = 236.04/54; CFI = .966) supported indirect and direct effects of neighborhood safety on PA changes during COVID-19 restrictions, and the youth’s ability to respond to COVID-19 restrictions served as a full mediator. Low-SES and Hispanic minority youth reported significantly less safety to walking or playing in their neighborhoods than their middle-/high-SES non-Hispanic peers (p < .001). Regardless of ethnicity, the magnitude of the reduction of MVPA was significantly higher among low-SES groups than that of the high- and middle-SES groups (p < .001).

Conclusions

These findings demonstrate a need to tailor programs and policies to help high-risk groups (e.g., low SES) stay active, healthy, and resilient during and after the COVID-19 pandemic.

Reliability of the Expanded Cutting Alignment Scoring Tool (E-CAST) to Assess Trunk and Limb Alignment During a 45-Degree Side-Step Cut

Background

Current clinical screening tools assessing risky movements during cutting maneuvers do not adequately address sagittal plane foot and ankle evaluations. The Cutting Alignment Scoring Tool (CAST) is reliable in evaluating frontal plane trunk and lower extremity alignment during a 45-degree side-step cut. The Expanded Cutting Alignment Scoring Tool (E-CAST) includes two new sagittal plane variables, knee flexion and ankle plantarflexion angle.

Hypothesis/Purpose

To assess the inter-and intra-rater reliability of the E-CAST to evaluate trunk and lower extremity alignment during a 45-degree side-step cut.

Study Design

Repeated Measures.

Methods

Participants included 25 healthy females (13.8 ± 1.4 years) regularly participating in cutting or pivoting sports. Participants were recorded performing a side-step cut in frontal and sagittal planes. One trial was randomly selected for analysis. Two physical therapists independently scored each video using the E-CAST on two separate occasions, with randomization and a two-week wash-out between rounds. Observed movement variables were awarded a score of "1", with higher scores representing poorer technique. Intraclass correlation coefficients (ICC) and 95% confident intervals (95% CI) were calculated for the total score, and a kappa coefficient (k) was calculated for each variable.

Results

The cumulative intra-rater reliability was good (ICC=0.78, 95% CI 0.59-0.96) and the cumulative inter-rater reliability was moderate (ICC=0.71, 95% CI 0.50-0.91). Intra-rater kappa coefficients ranged from moderate to excellent for all variables (k= 0.50-0.84) and inter-rater kappa coefficients ranged from slight to excellent for all variables (k=0.20-0.90).

Conclusion

The addition of two sagittal plane variables resulted in lower inter-rater ICC compared to the CAST (ICC= 0.81, 95% CI 0.64-0.91). The E-CAST is a reliable tool to evaluate trunk and LE alignment during a 45-degree side-step cut, with good intra-rater and moderate inter-rater reliability.

Level of Evidence

Level 2, Diagnosis.

The impact of the coronavirus disease 2019 pandemic on physical activity in U.S. children

BACKGROUND

Daily moderate-to-vigorous physical activity (MVPA) is vital to the physical, mental, and social well-being of children. Early restrictions during the coronavirus disease 2019 (COVID-19) pandemic included the closure of schools and physical activity (PA) amenities across the US. This study aimed to examine the impact of the pandemic on the PA and play behavior of U.S. children and to provide evidence-based recommendations to improve their PA.

METHODS

A cross-sectional, online, parent-reported survey was conducted of children aged 3-18 years between April and June 2020 to assess light PA and MVPA using a modified Godin Leisure-Time Exercise Questionnaire. Additional items included family/child socioeconomic demographics, child adaptability to the pandemic, and community access. The survey was shared through social media and snowball sampling distribution.

RESULTS

Analysis of 1310 surveys indicated child PA scores declined significantly during the pandemic (from 56.6 to 44.6, max 119, p < 0.001). Specifically, MVPA score decreased (from 46.7 to 34.7, max 98, p < 0.001) while light PA remained the same. Age-based changes were seen in the quantity, variety, and intensity of PA, with the lowest pandemic-related impact seen in preschoolers and the highest in high schoolers (-4.7 vs. -17.2, p < 0.001). Community-based peer PA decreased across all age groups.

CONCLUSION

This study shows decreased PA levels in U.S. children, according to parent reporting, during the COVID-19 pandemic. Recommendations for community leaders, educators, and parents to improve PA in children are provided. With continued spread of COVID-19, these results and recommendations may be imperative to the physical well-being of U.S. children.

The relationship of coronal trunk motion on the hip abductor moment impulse in pre-operative hip pathology patients during walking

BACKGROUND

Compensatory mechanisms for hip pain, pathology, and weakness include excessive trunk lean towards the stance limb, counteracting pelvic drop to maintain stability during single leg stance. Trunk lean shifts the center of mass towards the hip joint center to decrease the moment arm and reduce hip abductor demand. The purpose of this study was to evaluate whether adolescent patients with symptomatic hip pain demonstrate excessive trunk lean and the effect on the hip abductor moment impulse.

METHODS

Self-selected speed walking data collected through an approved study were reviewed on pre-operative patients clinically diagnosed with a hip deformity. Instrumented motion analysis was performed to analyze trunk kinematics and the hip abductor moment impulse.

FINDINGS

There was a weak, but significant correlation between hip abductor moment impulse and trunk lean. Patients diagnosed with Acetabular Dysplasia demonstrated an increased trunk lean and a decreased hip abductor moment impulse (r = - 0.311, p = 0.001). Of those who presented with excessive trunk lean, 62% of these patients had a normal hip abductor moment impulse. There was no correlation between hip abductor moment impulse and hip abductor strength.

INTERPRETATION

Excessive trunk lean was not seen uniformly across adolescent patients with symptomatic hip deformities, despite pain being reported in 80% of patients. Furthermore, a majority of those that presented with excessive trunk lean did not present with a reduced moment, suggesting that although the amount of lean was greater than normal, it was not enough to significantly reduce the demand on the hip musculature.

Validation of Accelerometry Data to Identify Movement Patterns During Agility Testing

Purpose: The purpose of this study was to develop an algorithm for the detection and timing of foot contact/off timing for each lateral repetition and assess the validity/reliability of the calculated timings.

Methods: Participants performed a modified Edgren Side Step Test in which they moved laterally along a 4-m path as quickly as possible while wearing an accelerometer on each ankle. Time of completion of each attempt was recorded using a stopwatch and digital video was obtained. Accelerometer-based (ACC) events were determined for the start of the test (START), foot contact at the end-line (FC) and the lifting of the foot when transitioning to the other direction (FO). Based on these ACC events the Overall, Split (ST) and Lag (LT) times were determined and compared to either the stopwatch or video-based timings (p < 0.05). The ACC event criterion was then applied by independent reviewers to assess inter/intra-rater reliability of identifying the events.

Results: There was no significant difference in ACC (12.37 ± 2.19 s) based Overall Time compared to the Stopwatch (12.42 ± 2.25 s, p = 0.34). Bland-Altman plots for ST and LT revealed very good agreement between the ACC time to the Video (ST: Bias = 0.11 s, LOA −0.57 to 0.79; LT: Bias = −0.11 s, LOA −0.43 to 0.22). Intra and inter-rater reliability was moderate to excellent for all reviewer identified events.

Conclusions: This study demonstrates methodology to identify ACC based timings during an agility test. The inclusion of an accelerometer supplements standard timing options with the added benefit of assessing sided split and lag times.

Rectus-sparing approach to the periacetabular osteotomy in adolescents preserves hip flexion strength

PURPOSE

The classic periacetabular osteotomy (PAO) approach can result in hip flexor weakness in adolescents. The rectus-sparing approach (PAO-RS) preserves the origin of the rectus femoris tendon which may prevent hip flexor weakness and improve functional outcome.

METHODS

This is a prospective analysis of adolescents treated with a PAO or PAO-RS. The PAO group included 24 hips/21 patients (18 female, meanage 16 years (sd 4)); the PAO-RS group included ten hips (eight female, mean age 16 years (sd 1)). Preoperatively, the PAO group had decreased hip flexion strength compared with the PAO-RS group (83 Nm/kg versus 102 Nm/kg). A subset of PAO patients (n = 13 hips/12 patients, nine female, mean age 15 years (sd 3)) were matched for preoperative flexion strength to the PAO-RS group. Radiographic parameters, modified Harris hip score (mHHS), isokinetic hip strength and instrumented motion analysis preoperatively, six months and one-year postoperatively were compared.

RESULTS

There were no differences in preoperative deformity, postoperative correction or degree of correction between groups. Hip flexor strength decreased significantly at six months in the PAO group compared with the PAO-RS group (-35 Nm/kg versus -7 Nm/kg; p = 0.012), as did hip flexion pull-off power (1.33 W/kg PAO versus 1.76 W/kg PAO-RS; p = 0.010). Hip flexion strength improved from six months to one year in the PAO group, with no significant differences in strength at one year between groups (80 Nm/kg versus 90 Nm/kg). There were no differences between groups in mHHS any time point; both groups improved significantly postoperatively.

CONCLUSION

Preserving the rectus femoris may lead to improved short-term hip flexor strength and pull-off power. Further assessment at long-term follow-up is needed to determine if this strength leads to improved functional outcomes.

LEVEL OF EVIDENCE

II.

A combined method for binning coupling angles to define coordination patterns

The vector coding technique has been used to quantify coordination of two joints, segments, and/or planes during cyclic activities, such as walking. Coordination patterns can be identified by categorizing the tangent lines of an angle-angle plot by their direction, termed "coupling angle binning" or "phase binning". In the literature the ranges of directions, or "bins", originally divided by Chang et al. and more recently by Needham et al. have different strengths. Chang's method identifies general patterns with large bins while Needham's method identifies a dominant joint or segment in the pattern. This study created a novel method that incorporates bin categories from both methods, and therefore recognizes both general patterns and a dominant contributor when appropriate. This new method, the SRC method, as well as the two existing methods, were used to quantify knee-ankle coordination in the sagittal plane for healthy individuals and an individual with clubfoot during gait. Similarities and differences in classification between methods were compared and further investigated by interpreting the uncoupled angular data. Each method was then used to evaluate sagittal-coronal coordination of the forefoot in an individual with clubfoot during gait. This was done to demonstrate across-plane coordination analysis, to confirm that the advantages of the combined method extend to coupling pairs with like ranges of motion, and to present a clinical application. It was found that the TSRH binning methods provides a more complete description of coordination by including coordination categories defined by both the Chang and Needham method.

Compensatory sagittal plane ankle gait mechanics: Are they present in patients with a weak or stiff hip?

INTRODUCTION

Simulations suggest that subjects with reduced hip range of motion (ROM) and/or weakness can achieve more normal walking mechanics through compensations at the ankle. The aims of this study were to assess whether subjects with reduced hip ROM (Stiff hip) or hip flexor weakness (Weak hip) exhibit ankle compensations during walking and investigate redistribution of power in the lower extremity joints.

METHODS

Retrospective gait data were reviewed (IRB-approved hip registry). Preoperative kinematic/kinetic walking data were collected in patients with: adolescent hip dysplasia (AHD), femoral acetabular impingement (FAI), and Legg-Calvé Perthes disease (Perthes). AHD patients with significantly weak hip flexors on their affected side were included (Weak hip group). The Gait Profile Score (GPS) was calculated on the affected side of the FAI and Perthes groups to identify patients who had a Stiff hip. Patients who had undergone a hip arthrodesis (Fusion) were also included (Stiff hip group). Ankle kinematics/kinetics were compared to healthy participants (Control). The total positive work of sagittal plane hip, knee and ankle power were compared along with the distribution of power.

RESULTS

Patients in the Weak/Stiff hip groups did not walk with greater ankle plantarflexion, peak push-off power or positive ankle work on their affected sides compared to Control. Ankle work contribution (percentage of total positive work) on the affected or unaffected sides was greater in the Perthes and Hip Fusion patients compared to Control. Significant gait abnormalities on the unaffected side were observed.

CONCLUSIONS

Patients with a weak or stiff hip did exhibit altered ankle mechanics during walking. Greater percent ankle work contribution appeared to correspond with hip stiffness. In patients with hip pathology the redistribution of power among the lower extremity joints can highlight the importance of preserving ankle function.

Amputation Versus Staged Reconstruction for Severe Fibular Hemimelia: Assessment of Psychosocial and Quality-of-Life Status and Physical Functioning in Childhood

Background

Fibular hemimelia, a congenital disorder characterized by the partial or complete absence of the fibula, tibial growth inhibition, and foot and ankle deformity and deficiency, is the most common deficiency of long bones. The purpose of the present study of children with congenital fibular hemimelia was to examine the functional and psychosocial outcomes at a minimum of 2 years after treatment either with amputation and a prosthesis or with reconstruction and lengthening.

Methods

Twenty children who were managed with primary amputation were compared with 22 children who were managed with staged limb reconstruction. The average age of the patients at the time of evaluation was 9 years (range, 5 to 15 years). Patients and parents completed psychosocial, quality-of-life, and satisfaction surveys. Patients underwent instrumented gait analysis and a timed 25 or 50-yard dash. The number and nature of surgical procedures were recorded from a retrospective chart review.

Results

Families of children managed with amputation had lower economic and educational levels and were more ethnically diverse compared with the families of children managed with limb reconstruction. Scores on psychosocial and quality-of-life surveys were comparable with those from healthy patient populations. Parents of males treated with amputation perceived a lower school-related quality of life for their child; socioeconomic and ethnic differences between groups might account for this finding. Statistically but not clinically significant differences were measured during instrumented gait analysis at a self-selected walking speed and during a timed 25 or 50-yard dash. The majority of patients and parents reported satisfaction with the treatment method selected and would select the same treatment method again.

Conclusions

At this interim stage of growth, there were no significant functional or psychological differences between groups. Both groups were satisfied with the outcome in mid-childhood, irrespective of the selection of amputation or limb reconstruction.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Long-term Outcomes of Operative and Nonoperative Treatment of Congenital Coxa Vara

BACKGROUND

Congenital coxa vara (CCV) is a rare hip condition with few long-term studies. The purpose of this study was to assess clinical, radiographic, and functional outcomes after operative and nonoperative treatment of CCV, assess reliability of radiographic parameters, and investigate risk factors for recurrence after surgery.

METHODS

Retrospective review was performed of all CCV patients treated at 1 institution from 1980 to 2010. In addition, patients were recalled for additional follow-up x-rays, modified Harris Hip Score (mHHS), and gait analysis. Radiographic measurements [neck-shaft angle (NSA), head-shaft angle (HSA), Hilgenreiner-epiphyseal angle (HEA), and femoral neck length (FNL)] were assessed for reliability using intraclass correlation coefficients. Multivariate analysis was performed to identify risk factors for recurrence after surgery.

RESULTS

Forty-six hips in 32 patients were reviewed. Mean age at presentation was 5.4±4.9 years. Mean follow-up was 11.8±5.8 years. Valgus proximal femoral osteotomy was performed in 27 hips (20 patients). Initial deformity was greater in the operative group (NSA 90±17 degrees, HEA 68±19 degrees) versus nonoperative patients (NSA 122±19 degrees, HEA 34±14 degrees) (P<0.0001), but radiographic outcomes were similar at follow-up. Most nonoperative hips had normal FNL growth rates (80%), but resolution of varus NSA occurred in only 21%. In contrast, 56% of operative hips showed decreased FNL growth rates. Interobserver reliability was excellent for HEA (0.98), NSA (0.90), and FNL (0.89), and good for HSA (0.79). Repeat osteotomy was performed in 6 cases (22%). No significant predictors for recurrence were identified. At long-term follow-up for recalled patients, 72% had significantly abnormal gait, and 50% had fair-poor functional outcomes (mHHS<79).

CONCLUSIONS

Valgus osteotomy corrects severe deformity in CCV with improved clinical and radiographic outcomes. HEA and NSA are the most reliable radiographic measurements of proximal femoral deformity in CCV. Recurrence is not uncommon, but no predictors were identified. Many patients have persistent gait abnormalities and functional impairment at long-term follow-up, regardless of prior treatment.

LEVEL OF EVIDENCE

Level III-retrospective cohort.

Automated event detection algorithm for two squatting protocols

INTRODUCTION

Squatting biomechanics assessed using motion analysis relies on the identification of specific events: start of descent, transition between descent/ascent and end of ascent. Automated identification reduces the time needed to process trials while allowing consistency across studies. The purpose of this study was to develop criteria for the identification of events and apply them to two squatting protocols in pathological patient and typically developing (TD) groups.

METHODS

Thirty-four subjects with hip dysplasia and 41 TD subjects were enrolled in this study. While instrumented with a full-body Plug-In-Gait marker set, participants performed two squatting protocols: a hold squat, where subjects paused for a count of three at their lowest squat depth, and a traditional squat, where the descent phase was immediately followed by the ascent phase. Reviewers analyzed the kinematic/kinetic waveforms of a subset of trials to develop criteria for events. Sagittal plane knee and vertical center of mass velocities were used to identify events and absolute vs. relative thresholds of the peak knee velocity were compared. These criteria were incorporated into an automatic event detection code.

RESULTS

Using a relative threshold algorithm, events were automatically identified in 244 of 259 total trials (94%). For the trials requiring manual placement of events (n=15 trials), there was perfect inter-rater reliability between research personnel.

CONCLUSIONS

The criteria developed for the automatic detection of squatting events was highly successful for both protocols in each participant group and was also highly reliable for research personnel to follow in the few instances where manual placement was necessary.

Interval setting selection affects ambulatory activity outputs in children with cerebral palsy

INTRODUCTION

Accelerometer based devices have been widely used to assess the ambulatory activity of children with and without functional disabilities. Many researchers who utilize the StepWatch Activity Monitor (SAM) collect at a 60second (60sec) interval setting. The purpose of this study was to assess the effect of SAM interval settings on ambulatory activity outputs in children with cerebral palsy (CP) and typically developing youth.

METHODS

Participants wore a SAM which recorded the number of strides every 10seconds (10s) for one week. Raw 10s data was downsampled to combine strides into 60sec intervals. Strides were ensembled into walking bouts with the Intensity/Duration calculated as a percentage of Total Ambulatory Time (TAT).

RESULTS

Twenty-eight children with CP (14 boys; avg. 12 yrs. 4 mths.; GMFCS Level I n=4, Level II n=19, Level III n=5) completed testing and 28 age matched typically developing youth (14 boys; avg. 12 yrs. 6 mths.) were included. Using the 10sec interval, ∼80% of walking bouts in both groups were less than or equal to 60s. Data recorded at 60sec intervals had higher daily TAT but fewer walking bouts. In children with CP, daily steps were higher using the 60sec interval. At the Easy intensity, the 60sec interval reported an increased volume of Long duration walking, and it rarely identified any Moderate+ intensity activity.

CONCLUSIONS

60sec interval data overestimated low intensity and long duration ambulatory activity. It is imperative that investigators choose a finer interval setting (10sec) to maximize the detection of gait transitions and rest periods which are critical in describing community ambulation of patients with cerebral palsy.

Evaluation of cortical plasticity in children with cerebral palsy undergoing constraint-induced movement therapy based on functional near-infrared spectroscopy

Sensorimotor cortex plasticity induced by constraint-induced movement therapy (CIMT) in six children (10.2±2.1 years old) with hemiplegic cerebral palsy was assessed by functional near-infrared spectroscopy (fNIRS). The activation laterality index and time-to-peak/duration during a finger-tapping task and the resting-state functional connectivity were quantified before, immediately after, and 6 months after CIMT. These fNIRS-based metrics were used to help explain changes in clinical scores of manual performance obtained concurrently with imaging time points. Five age-matched healthy children (9.8±1.3 years old) were also imaged to provide comparative activation metrics for normal controls. Interestingly, the activation time-to-peak/duration for all sensorimotor centers displayed significant normalization immediately after CIMT that persisted 6 months later. In contrast to this improved localized activation response, the laterality index and resting-state connectivity metrics that depended on communication between sensorimotor centers improved immediately after CIMT, but relapsed 6 months later. In addition, for the subjects measured in this work, there was either a trade-off between improving unimanual versus bimanual performance when sensorimotor activation patterns normalized after CIMT, or an improvement occurred in both unimanual and bimanual performance but at the cost of very abnormal plastic changes in sensorimotor activity.

Motion tracking and electromyography-assisted identification of mirror hand contributions to functional near-infrared spectroscopy images acquired during a finger-tapping task performed by children with cerebral palsy

Recent studies have demonstrated functional near-infrared spectroscopy (fNIRS) to be a viable and sensitive method for imaging sensorimotor cortex activity in children with cerebral palsy (CP). However, during unilateral finger tapping, children with CP often exhibit unintended motions in the nontapping hand, known as mirror motions, which confuse the interpretation of resulting fNIRS images. This work presents a method for separating some of the mirror motion contributions to fNIRS images and demonstrates its application to fNIRS data from four children with CP performing a finger-tapping task with mirror motions. Finger motion and arm muscle activity were measured simultaneously with fNIRS signals using motion tracking and electromyography (EMG), respectively. Subsequently, subject-specific regressors were created from the motion capture or EMG data and independent component analysis was combined with a general linear model to create an fNIRS image representing activation due to the tapping hand and one image representing activation due to the mirror hand. The proposed method can provide information on how mirror motions contribute to fNIRS images, and in some cases, it helps remove mirror motion contamination from the tapping hand activation images.