Individualized orthotic alignment and footwear for balance and mobility in children with bilateral spastic cerebral palsy: A randomized trial.

AIM: To examine whether designed-to-be-rigid ankle-foot orthoses and footwear combinations with individualized alignment and footwear designs (AFO-FC/IAFD) would be more effective than designed-to-be-rigid AFO with non-individualized alignment and footwear designs (AFO-FC/NAFD) in children with cerebral palsy (CP). METHOD: Nineteen children with bilateral spastic CP were randomized to AFO-FC/NAFD (n = 10) or AFO-FC/IAFD (n = 9) groups. Fifteen were male, average age 6 years 11 months (range 4 years 2 months-9 years 11 months), classified in Gross Motor Function Classification System levels II (n = 15) and III (n = 4). The Pediatric Balance Scale (PBS), Gait Outcomes Assessment List (GOAL), Patient-Reported Outcomes Measurement Information System (PROMIS), and Orthotic and Prosthetic Users' Survey (OPUS) measures of satisfaction were collected at baseline and after 3 months' wear. RESULTS: Compared with the AFO-FC/NAFD group, those with AFO-FC/IAFD demonstrated greater change in PBS total scores (mean 12.8 [standard deviation 10.5] vs 3.5 [5.8]; p = 0.03) and GOAL total scores (3.5 [5.8] vs -0.44 [5.5]; p = 0.03). There were no significant changes in OPUS or PROMIS scores. INTERPRETATION: After 3 months, individualized orthosis alignment and footwear designs had a greater positive effect on balance and parent-reported mobility than a non-individualized approach. No effect was documented for the PROMIS and OPUS. Results may inform orthotic management for ambulatory children with bilateral spastic CP. WHAT THIS PAPER ADDS: Balance and parent-reported mobility increased more over time for the ankle-foot orthoses and footwear combinations with individualized alignment and footwear designs (AFO-FC/IAFD) group. Changes in balance over time suggest a therapeutic effect of the AFO-FC/IAFD approach.

Comparison of Sagittal Plane Stiffness of Nonarticulated Pediatric Ankle-Foot Orthoses Designed to be Rigid.

INTRODUCTION: When studying the effect of ankle-foot orthoses (AFOs) on gait, it is important to know their sagittal plane stiffness. However, there are no established thresholds for stiffness of non-articulated AFOs designed to be rigid. If wanting to implement published algorithms for ankle-foot orthosis-footwear combinations (AFO-FCs), the AFOs must be equally as stiff as those of the developer of the published AFO-FC algorithms. Hence, the aim of this work was to compare the sagittal plane stiffness of AFOs designed to be rigid, made for a clinical trial in the USA, and following algorithms for AFO-FC designs, to those made and used clinically in the UK by the developer of the AFO-FC algorithms. MATERIALS AND METHODS: Stiffness of 9 pediatric polypropylene AFOs was tested (UK: 6; USA: 3). A computer-controlled motorized device was used in which all AFOs were clamped with the calf shell in a fixed vertical component and the foot section in a rotating plate. Each AFO was tested for 3 trials, loading the foot plate 30 Nm towards dorsiflexion and 20 Nm towards plantarflexion. Torque-angle graphs were plotted and deflection and stiffness compared descriptively across AFOs. RESULTS: Average deflection of AFOs was UK: 3.42±0.83° and USA: 4.81±1.05°. Average stiffness of AFOs was UK: 14.34±3.34 Nm/° and USA: 10.30±1.92 Nm/°. CONCLUSIONS: All tested AFOs deflected only a few degrees in either direction (range: 2.59° to 6.02°), providing the first information reported for the stiffness of rigid pediatric non-articulated AFOs. Overall, the UK AFOs were stiffer and deflected less than the USA study AFOs. AFO design features should be carefully considered as they likely influence sagittal plane stiffness and deflection under load.

Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis.

Understanding the mechanical properties of ankle-foot orthoses (AFOs) is important to maximize their benefit for those with movement disorders during gait. Though mechanical properties such as stiffness and/or energy efficiency of AFOs have been extensively studied, it remains unknown how and to what extent shoes influence their properties. The aim of this study was to investigate the effect of shoes on stiffness and energy efficiency of an AFO using a custom mechanical testing device. Stiffness and energy efficiency of the AFO were measured in the plantar flexion and dorsiflexion range, respectively, under AFO-alone and AFO-Shoe combination conditions. The results of this study demonstrated that the stiffness of the AFO-Shoe combination was significantly decreased compared to the AFO-alone condition, but no significant differences were found in energy efficiency. From the results, we recommend that shoes used with AFOs should be carefully selected not only based on their effect on alignment of the lower limb, but also their effects on overall mechanical properties of the AFO-Shoe combination. Further study is needed to clarify the effects of differences in shoe designs on AFO-Shoe combination mechanical properties.

The Effect of Ankle-Foot Orthoses on Community-Based Walking in Cerebral Palsy: A Clinical Pilot Study.

PURPOSE: To examine the effect of ankle-foot orthoses (AFO) on walking activity in children with cerebral palsy (CP). METHODS: We used a randomized cross-over design with 11 children with bilateral CP, mean age 4.3 years. Subjects were randomized to current AFO-ON or AFO-OFF for 2 weeks and then crossed over. Walking activity (average total steps/day), intensity, and stride rate curves were collected via an ankle accelerometer. Group effects were examined with the Wilcoxon signed-rank test and within-subject effects examined for more than 1 standard deviation change. RESULTS: No significant group difference was found in average total daily step count between treatment conditions (P = .48). For the AFO-ON condition, 2 subjects (18%) increased total steps/day; 4 (36%) increased walking time; 2 (18%) had more strides at a rate of more than 30 strides/min; and 2 (18%) reached higher peak intensity. CONCLUSIONS: Clinically prescribed AFO/footwear did not consistently enhance walking activity levels or intensity. Larger studies are warranted.

A proposed evidence-guided algorithm for the adjustment and optimization of multi-function articulated ankle-foot orthoses in the clinical setting.

Individuals with neuromuscular pathologies are often prescribed an ankle-foot orthosis (AFO) to improve their gait mechanics by decreasing pathological movements of the ankle and lower limb. AFOs can resist or assist excessive or absent muscular forces that lead to tripping, instability, and slow inefficient gait. However, selecting the appropriate AFO with mechanical characteristics, which limit pathological ankle motion in certain phases of the gait cycle while facilitating effective ankle movement during other phases, requires careful clinical decision-making. The aim of this study is to propose an explicit methodology for the adjustment of multi-function articulated AFOs in clinical settings. A secondary aim is to outline the evidence supporting this methodology and to identify gaps in the literature as potential areas for future research. An emerging class of AFO, the multi-function articulated AFO, offers features that permit more comprehensive, iterative, and reversible adjustments of AFO ankle alignment and resistance to ankle motion. However, no standard method exists for the application and optimization of these therapeutic devices in the clinical setting. Here we propose an evidence-guided methodology applicable to the adjustment of multi-function articulated AFOs in the clinical setting. Characteristic load-deflection curves are given to illustrate the idealized yet complex resistance-angle behavior of multi-function articulated AFOs. Research is cited to demonstrate how these mechanical characteristics can help mitigate specific pathologic ankle and knee kinematics and kinetics. Evidence is presented to support the effects of systematic adjustment of high resistance, alignable, articulated AFOs to address many typical pathomechanical patterns observed in individuals with neuromuscular disorders. The published evidence supporting most decision points of the algorithm is presented with identified gaps in the evidence. In addition, two hypothetical case examples are given to illustrate the application of the method in optimizing multi-function articulated AFOs for treating specific gait pathomechanics. This method is proposed as an evidence-guided systematic approach for the adjustment of multi-function articulated AFOs. It utilizes observed gait deviations mapped to specific changes in AFO alignment and resistance settings as a clinical tool in orthotic treatment for individuals with complex neuromuscular gait disorders.

Comparative gait analysis of ankle arthrodesis and arthroplasty: initial findings of a prospective study.

BACKGROUND: Little is known about functional outcomes of ankle arthroplasty compared with arthrodesis. This study compared pre-surgical and post-surgical gait measures in both patient groups. METHODS: Eighteen patients with end-stage ankle arthritis participated in an ongoing longitudinal study (pre-surgery, 12 months post-surgery) involving gait analysis, assessment of pain and physical function. Outcome measures included temporal-distance, kinematic and kinetic data, the Short Form 36 (SF-36) body pain score, and average daily step count. A mixed effects linear model was used to detect effects of surgical group (arthrodesis and arthroplasty, n = 9 each) with walking speed as a covariate (α = 0.05). RESULTS: Both groups were similar in demographics and anthropometrics. Followup time was the same for each group. There were no complications in either group. Pain decreased (p < 0.001) and gait function improved (gait velocity, p = 0.02; stride length, p = 0.035) in both groups. Neither group increased average daily step count. Joint range of motion (ROM) differences were observed between groups after surgery (increased hip ROM in arthrodesis, p = 0.001; increased ankle ROM in arthroplasty, p = 0.036). Peak plantar flexor moment increased in arthrodesis patients and decreased in arthroplasty patients (p = 0.042). CONCLUSION: Initial findings of this ongoing clinical study indicate pain reduction and improved gait function 12 months after surgery for both treatments. Arthroplasty appears to regain more natural ankle joint function, with increased ROM. Long-term follow up should may reveal more clinically meaningful differences.

Effect of types of ankle-foot orthoses on energy expenditure metrics during walking in individuals with stroke: a systematic review.

PURPOSE: This systematic review is aimed at evaluating the efficacy of AFO types and comparison between them on the energy expenditure metrics of walking in individuals who had suffered a stroke with (sub)acute or chronic evolution. METHODS: The following databases were searched; PubMed, Scopus, ISI Web of Knowledge, Embase and Cochrane Library based on the population intervention comparison outcome (PICO) method. RESULTS: A total of 15 trials involving 195 participants were selected for the final evaluation. All trials, except one, examined individuals in chronic phase. Although the evidence from the selected studies was generally weak, the consensus was that an AFO may have a positive immediate effect on the energy expenditure metrics including energy cost, physiological cost index, mechanical work and vertical center of mass trajectory on the affected leg, in both overground walking and treadmill walking in adults with chronic stroke. There were insufficient studies to evaluate the medium term efficacy of wearing an AFO combined with gait training on metabolic cost parameters during ambulation. There were also insufficient studies for comparison among different designs of AFOs. CONCLUSIONS: An AFO can immediately improve energy expenditure metrics of walking in stroke survivors. There is a need for further well-designed randomized trials to evaluate long-term effect of gait training using AFOs and comparison among the different types of orthoses.IMPLICATIONS FOR REHABILITATIONAn AFO can immediately improve the energy expenditure metrics during walking after stroke.Measurement of energetic parameters of walking wearing a orthotic device such as an AFO can evaluate gait economy in stroke populations.

Effect of ankle-foot orthoses on functional outcome measurements in individuals with stroke: a systematic review and meta-analysis.

PURPOSE: To determine and compare the effect of ankle-foot orthosis (AFOs) types on functional outcome measurements in individuals with (sub)acute or chronic stroke impairments. METHODS: PubMed, Web of Knowledge, Embase, Scopus, ProQuest, and Cochrane were searched from inception until September 2020. Methodological quality assessment of 30 studies was conducted based on the Downs and Black checklist. Functional indices were pooled according to their standardized mean difference (SMD) and 95% confidence intervals (CI) in a random-effect model. A narrative analysis was performed where data pooling was not feasible. RESULTS: Overall pooled results indicated improvements in favor of AFOs versus without for the Berg Balance Scale (SMD: 0.54, CI: 0.19-0.88), timed-up and go test (SMD: -0.45, CI: -0.67 to -0.24), Functional Ambulatory Categories (SMD: 1.72, CI: 1.25-2.19), 6-Minute Walking Test (SMD: 0.91, CI: 0.53-1.28), Timed Up-Stairs (SMD: -0.35, CI: -0.64 to 0.05), and Motricity Index (SMD: 0.65, CI: 0.38-0.92). Heterogeneity was non-significant for all outcomes (I2 < 50%, p > 0.05) except the Berg Balance Scale and Functional Ambulatory Categories. Additionally, there was not sufficient evidence to determine the effectiveness of specific orthotic designs over others. CONCLUSIONS: An AFO can improve ambulatory function in stroke survivors. Future studies should explore the long-term effects of rehabilitation using AFOs and compare differences in orthotic designs.IMPLICATIONS FOR REHABILITATIONAn AFO can improve functional performance and ambulation in survivors of strokes.Wearing an AFO in rehabilitation care during the subacute phase post stroke may have beneficial effects on functional outcomes measured.There was no evidence as to the effectiveness of specific AFO designs over others.

The impact of ankle-foot orthosis's plantarflexion resistance on knee adduction moment in people with chronic stroke.

BACKGROUND: An ankle-foot orthosis (AFO) is used to assist gait of people with chronic stroke. It is widely accepted that AFO's plantarflexion resistance affects sagittal knee moments during their gait. However, its effect on the coronal knee moment remains unclear. This study aimed to examine the effects of varying articulated AFO's plantarflexion resistance on knee adduction moment in people with chronic stroke. METHODS: Ten people with chronic stroke participated in this study. Gait performance was measured using a Vicon 3-dimensional motion capture system and a Bertec split-belt instrumented treadmill. The participants walked on the treadmill wearing an articulated AFO whose plantarflexion resistance could be systematically adjusted. The ankle joints were set to four distinct levels of plantarflexion resistance (S1 < S2 < S3 < S4). The coronal ankle and knee joint moment, center of pressure, and ground reaction force were analyzed using Visual3D. RESULTS: The external knee adduction moment increased significantly ( P < .001) and the position of the center of pressure trajectory shifted significantly ( P = .003) in the medial direction as the plantarflexion resistance of the AFO was increased from the least resistive condition (S1) to the most resistive condition (S4). The maximum knee adduction moment (median [interquartile range]) was S1: 0.097 (-0.012 to 0.265) Nm/kg; S2: 0.136 (0.040 to 0.287) Nm/kg; S3: 0.160 (0.465 to 0.289) Nm/kg; and S4: 0.192 (0.080 to 0.288) Nm/kg. CONCLUSIONS: This study demonstrated that varying AFO's plantarflexion resistance altered the knee adduction moment, likely by altering the center of pressure trajectory while walking, in people with chronic stroke.

Intensity and duration of intermittent exercise and recovery during a soccer match.

Soccer is a sport consisting of high-intensity intermittent exercise, with players making forays across their anaerobic threshold for tactical advantage followed by periods of recovery. The intensity and duration of these work and recovery bouts were defined during a men's soccer match using StepWatch Activity Monitors recording step rate for each 3-second period. The data were coded by custom software to separate work bouts (step rate ≥ 4) from recovery bouts (step rate < 4), and a square wave of the pattern of bouts was plotted for 5 players: center forward, central midfielder, wing midfielder, central defender, and wing defender. Four values were calculated for each work and recovery bout identified: duration, and mean, maximum, and minimum step rate (intensity). This novel technique provided detailed graphical information on the duration and exercise intensity of each position throughout the match. The center midfielder was able to sustain work and recovery bout characteristics throughout the match and appeared to recover at higher intensity levels than other players. The forward showed the consequence of accumulated fatigue late in the match and was unable to sustain the duration of high-intensity work bouts observed earlier in the match. The central defender attenuated the intensity of his work and recovery bouts late in the match staying closer to a more moderate work rate with fewer high- or low-intensity bouts. Having objective data qualifying players' work and recovery bout characteristics might prove valuable for tactical decision making, substitution timing, and for planning future training sessions.

Biomechanical analysis of stresses to the fifth metatarsal bone during sports maneuvers: implications for fifth metatarsal fractures.

Fifth metatarsal stress fractures are an increasing problem in elite and recreational athletic populations. One possible mechanism of injury is the many bending moments applied to the fifth metatarsal during dynamic sports maneuvers involving rapid changes in direction and speed. A potentially important bending moment is loading of the base versus the head of the fifth metatarsal, which tends to cause a bending moment along the bone. To determine which maneuver applies the greatest pressure differential between the base and head of the fifth metatarsal, 10 college-aged male athletes performed running straight, jump take-off, jump landing, cutting right, cutting left, and accelerating while plantar pressures were recorded using a Pedar insole system (Novel Electronics, Inc., St. Paul, MN). Peak pressure at the fifth metatarsal base was subtracted from the peak pressure at the fifth metatarsal head to obtain the fifth metatarsal pressure differential-a corollary to the bending moment. The greatest fifth metatarsal pressure differential was observed during acceleration maneuvers (20 + or - 13.1 N/cm(2); P < 0.0001) followed by running straight (11.6 + or - 8 N/cm(2); P < 0.0008). The other maneuvers had low pressure differentials: jump take-off (4.2 + or - 10.6 N/cm(2)), jump landing (3.7 + or - 9.2 N/cm(2)), cutting left (2.3 + or - 4.2 N/cm(2)), and cutting right (-2.1 + or - 10 N/cm(2)). It appears that acceleration maneuvers may apply the largest bending moments to the fifth metatarsal and could lead to stress fractures. Because fifth metatarsal stress fractures are associated with rapid increases in training volume, reducing the number of acceleration events may be effective in altering the balance between bone resorption and bone formation and reducing stress fracture risk. Careful planning of training programs allowing for adequate rest between intense bouts of exercise involving many acceleration maneuvers may be the best preventative measure.

The relationship between static and dynamic foot posture and running biomechanics: A systematic review and meta-analysis.

BACKGROUND: Medial longitudinal arch characteristics are thought to be a contributing factor to lower limb running injuries. Running biomechanics associated with different foot types have been proposed as one of the potential underlying mechanisms. However, no systematic review has investigated this relationship. RESEARCH QUESTION: The aim of this study was to conduct a systematic literature search and synthesize the evidence about the relationship between foot posture and running biomechanics. METHODS: For this systematic review and meta-analysis different electronic databases (Pubmed, Web of Science, Cochrane, SportDiscus) were searched to identify studies investigating the relationship between medial longitudinal arch characteristics and running biomechanics. After identification of relevant articles, two independent researchers determined the risk of bias of included studies. For homogenous outcomes, data pooling and meta-analysis (random effects model) was performed, and levels of evidence determined. RESULTS: Of the 4088 studies initially identified, a total of 25 studies were included in the qualitative review and seven in the quantitative analysis. Most studies had moderate and three studies a low risk of bias. Moderate evidence was found for a relationship between foot posture and subtalar joint kinematics (small pooled effects: -0.59; 95%CI -1.14 to - 0.003) and leg stiffness (small pooled effect: 0.59; 95%CI 0.18 to 0.99). Limited or very limited evidence was found for a relationship with forefoot kinematics, tibial/leg rotation, tibial acceleration/shock, plantar pressure distribution, plantar fascia tension and ankle kinetics as well as an interaction of foot type and footwear regarding tibial rotation. SIGNIFICANCE: While there is evidence for an association between foot posture and subtalar joint kinematics and leg stiffness, no clear relationship was found for other biomechanical outcomes. Since a comprehensive meta-analysis was limited by the heterogeneity of included studies future research would benefit from consensus in foot assessment and more homogenous study designs.

The effects of alignment of an articulated ankle-foot orthosis on lower limb joint kinematics and kinetics during gait in individuals post-stroke.

Mechanical tuning of an ankle-foot orthosis (AFO) is important in improving gait in individuals post-stroke. Alignment and resistance are two factors that are tunable in articulated AFOs. The aim of this study was to investigate the effects of changing AFO ankle alignment on lower limb joint kinematics and kinetics with constant dorsiflexion and plantarflexion resistance in individuals post-stroke. Gait analysis was performed on 10 individuals post-stroke under four distinct alignment conditions using an articulated AFO with an ankle joint whose alignment is adjustable in the sagittal plane. Kinematic and kinetic data of lower limb joints were recorded using a Vicon 3-dimensional motion capture system and Bertec split-belt instrumented treadmill. The incremental changes in the alignment of the articulated AFO toward dorsiflexion angles significantly affected ankle and knee joint angles and knee joint moments while walking in individuals post-stroke. No significant differences were found in the hip joint parameters. The alignment of the articulated AFO was suggested to play an important role in improving knee joint kinematics and kinetics in stance through improvement of ankle joint kinematics while walking in individuals post-stroke. Future studies should investigate long-term effects of AFO alignment on gait in the community in individuals post-stroke.

The relationship between lumbar lordosis angle and low back pain in individuals with transfemoral amputation.

BACKGROUND:: Low back pain is a common secondary disabling condition in the transfemoral amputee population. Transfemoral amputees are at risk of excessive lumbar lordosis; it has been suggested that increased lumbar lordosis may be associated with low back pain. However, the relationship between lumbar lordosis angle and low back pain has not yet been studied in this population. OBJECTIVE:: To determine whether the extent of lumbar lordosis is associated with low back pain in transfemoral amputees. STUDY DESIGN:: Case-control observational study. METHODS:: Participants included eight transfemoral amputees without low back pain and nine transfemoral amputees with low back pain. Etiology of amputation was primarily trauma. All participants underwent lateral view radiographs of the lumbar spine, from which lumbar lordosis angle and sacral inclination angle were measured. RESULTS:: Lumbar lordosis angle mean ± standard deviation was 46.1° ± 12.4° in participants with low back pain and 51.0° ± 12.6° in those without. Sacral inclination angle mean ± standard deviation was 38.3° ± 8.7° in participants with low back pain and 39.1° ± 7.5° in those without. There was no significant difference in lumbar lordosis angle or sacral inclination angle between participants with and without low back pain. CONCLUSION:: This study suggests that increased lumbar lordosis angle and sacral inclination angle are not significantly associated with low back pain in transfemoral amputees of a primarily traumatic etiology. CLINICAL RELEVANCE: Low back pain (LBP) is a common, disabling condition in transfemoral amputees. In the clinical setting, increased lumbar lordosis is implicated in LBP. This study does not support an association between increased lumbar lordosis and LBP; further study is needed to understand the increased prevalence of LBP in this population.

Step Activity After Surgical Treatment of Ankle Arthritis.

BACKGROUND: Ambulatory activity is reduced in patients with ankle arthritis. In this study, we measured step activity over time in 2 treatment groups and secondarily compared step activity with results of patient-reported outcome measures (PROMs). METHODS: Patients who were treated with either ankle arthrodesis or ankle arthroplasty wore a step activity monitor preoperatively and at 6, 12, 24, and 36 months postoperatively. Changes from preoperative baseline in total steps per day and per-day metrics of low, medium, and high-activity step counts were measured in both treatment groups. Step activity was compared with each subject's PROM scores as reported on the Musculoskeletal Function Assessment (MFA) and the Short Form-36 (SF-36) physical function and bodily pain subscales. RESULTS: Of the 3 activity levels, combined group high-activity step counts showed the greatest increase (mean of 278 steps [95% confidence interval (CI), 150 to 407 steps], a 46% improvement from preoperatively). At 6 months, the mean high-activity step improvement for the arthroplasty group was 194 steps compared with a mean decline of 44 steps for the arthrodesis group (mean 238-step difference [95% CI, -60 to 536 steps]). By 36 months postoperatively, the greater improvement in high-activity steps for the arthroplasty versus the arthrodesis group was no longer present. There were no significant pairwise differences in improvement based on surgical treatment method at any individual follow-up time point. For a within-patient increase of 1,000 total steps, there was a mean change in the MFA, SF-36 physical function, and SF-36 bodily pain scores of -1.8 (95% CI, -2.4 to -1.2), 3.8 (95% CI, 2.8 to 4.8), and 2.8 (95% CI, 1.8 to 3.9), respectively (p < 0.0001 for all associations). There was no evidence that the association differed by study visit, or by study visit and surgical procedure interaction (p > 0.10). CONCLUSIONS: Surgical treatment of ankle arthritis significantly improves ambulatory activity, with greater change occurring at high activity levels. Improvement may occur more quickly following arthroplasty than arthrodesis, but at 3 years, we detected no significant difference between the 2 procedures. Step counts, while associated with PROMs, do not parallel them, and thus may be a useful supplementary measure, particularly in longitudinal studies. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Graded exposure treatment for adolescents with chronic pain (GET Living): Protocol for a randomized controlled trial enhanced with single case experimental design.

Chronic musculoskeletal pain in adolescence is a significant public health concern with 3-5% of adolescents suffering from significant pain-related disability. Pain-related fear and avoidance of activities has been found to have a significant influence on pain outcomes in children and adolescents and is a risk factor for less favorable response to treatment. To address this need, we developed graded exposure treatment for youth with chronic pain (GET Living). We describe the rationale, design, and implementation of a two-group randomized controlled trial (RCT) enhanced with single-case experimental design (SCED) methodology with a sample of 74 adolescents with chronic musculosketal pain and their parent caregivers. GET Living includes education, behavioral exposures, and parent intervention jointly delivered by pain psychology and physical therapy providers. The multidisciplinary pain management control group includes pain psychology delivered education and pain self-management skills training (e.g., relaxation, cognitive skills) and separate physical therapy. Assessments include brief daily diaries (baseline to discharge, 7-days at 3-month and 6-month follow-up), comprehensive in-person evaluations at baseline and discharge, and questionnaire across all time points (baseline, discharge, 3-month and 6-month follow-up). Primary outcome is pain-related fear avoidance. Secondary outcome is functional disability. We also outline all additional outcomes, exploratory outcomes, covariates, and implementation measures. The objective is to offer a mechanism-based, targeted intervention to youth with musculoskeletal pain to enhance likelihood of return to function.

Local dynamic stability in turning and straight-line gait.

Successful community and household ambulation require the ability to navigate corners and maneuver around obstacles, posing unique challenges compared to straight-line walking. The challenges associated with turning may contribute to an increased incidence of falling and the occurrence of fall-related injuries. A measure of stability applied to turning gait may be able to quantify a system's response to naturally occurring disturbances associated with turning and identify subjects at greater risk of falling. An index of stability has been used previously to assess the rate of kinematic separation (local dynamic stability) during straight-line gait. The purpose of this study was to determine if local dynamic stability during constant speed turning is reduced compared to straight-line treadmill walking. Maximum finite-time Lyapunov exponents (lambda) were used to estimate the local stability of able-bodied subjects' (n=19) sagittal plane hip, knee, and ankle trajectories for turning compared to straight-line walking at two different walking speeds. Turning lambda was greater than straight lambda for the hip, right knee, and ankle (p<0.05). Turning lambda for the left knee angle was similar to straight lambda. There were no differences in lambda between left and right limbs for the hip and ankle and also no differences between the inside and outside limbs during turning for all joints. These findings indicate able-bodied subjects' hip, right knee, and ankle kinematics are less locally stable while turning than walking in a straight line and may be used as a comparative tool for determining the efficacy of therapeutic interventions for mobility-impaired populations.

Ground reaction forces and impulses during a transient turning maneuver.

Understanding the kinetic strategies of turning as expressed in ground reaction forces (GRFs) and impulses (GRIs) is necessary to design therapies and technologies to enable patients with ambulatory difficulties perform daily activities. Previous studies have reported data only for one step of the turn and expressed the data in terms of a global reference frame making it difficult to understand how the forces act on the body to cause a change in heading and orientation during a turn. This study is the first to report GRF and GRI data for three steps of a turn and express that data in terms of a body reference frame. Motion and GRF data were collected from 10 subjects walking at self-selected speeds along a straight path and performing 90 degrees left and right turns. During the left turn, turn initiation and apex steps were collected. During the right turn, turn termination steps were collected. GRF data were rotated to a reference frame whose origin was the body center of mass (COM) and aligned to the COM trajectory and then integrated to find the GRIs. In the medial-lateral direction, straight steps were characterized by a brief medial impulse at heel strike followed by a prolonged lateral impulse. Turn initiation and termination steps were both characterized by medial impulses spanning the entire stance phase while apex steps were characterized by a large lateral impulse. In the anterior-posterior direction, initiation steps had larger braking and smaller propulsive impulses than straight steps. Apex steps had larger propulsive impulses than straight steps, and termination steps had smaller braking and larger propulsive impulses than straight steps.

Kinetic mechanisms to alter walking speed.

A mechanism to modulate speed during human walking has not yet been proposed in the literature, even though changing walking speed is likely a necessary attribute of everyday ambulation. To understand how joint kinetics modulate walking speed 12 normal adults walked Fast (1.4m/s), Slow (1.0m/s), Accel (1.0-1.4m/s) and Decel (1.4-1.0m/s) trials while full body 3D kinematics and kinetics were collected. Reduced sagittal ankle plantarflexor moments were observed in Accel trials during early single limb stance (p<0.001) and increased sagittal plantarflexor moments were seen in Decel trials during early single limb stance (p<0.001) compared to steady speed walking. Modulating the sagittal ankle moment altered the center of pressure location and either attenuated (Accel) or accentuated (Decel) the early stance braking impulse to accelerate or decelerate the center of mass. The onset of walking speed changes occurred at approximately 15% of the gait cycle and did not support the concept of "controlled falling". Sagittal ankle push-off power appears a consequence of increased walking speed, but not the causative factor to increase walking speed.