Objective: Determine the association of walking cadence to incident and worsening knee pain and physical function over 2 years in adults with or at risk for knee OA. Design: Participants from the Multicenter Osteoarthritis study were included. Cadence was measured using a GAITRite walkway. Incident and worsening knee symptoms, pain with walking, and functional limitations were assessed at baseline and 2 years later. The association of cadence to each outcome was analyzed using log binomial regression. Cadence was assessed continuously as a 10-unit change and categorically using quartiles. Analyses were adjusted for age, sex, race, BMI, presence of tibiofemoral OA, depression, and history of knee injury. Sensitivity analyses were conducted for all outcomes adjusted for gait speed and stratified by sex. Results: Among 1600 participants (60.3 % female, age 67.1 f 7.7 years), lower cadence was not significantly associated with incident or worsening knee symptoms, pain with walking, or functional limitations. For every 10-step/ min decrease in cadence, the risk of incident knee symptoms increased by 10 % (RR = 1.10, 95%CI [0.97, 1.25]), though this was not statistically significant and was attenuated after adjusting for gait speed (RR = 0.95, 95%CI [0.80, 1.12]). No significant associations were observed for incident or worsening pain with walking or functional limitations. Sex-stratified analyses revealed inconsistent findings, including an increased risk for incident functional limitations in females (RR = 1.45, 95%CI [1.02, 2.08]), which was attenuated after adjusting for gait speed. Conclusion: Lower cadence was not significantly associated with pain and function, suggesting that the interplay between cadence, gait speed, and clinical outcomes warrants further investigation.

To assess the feasibility of a randomized controlled trial evaluating a gait retraining program to reduce peak tibial acceleration on knee pain and impact loading in adults with knee osteoarthritis. Participants (n = 44) were randomized to a gait retraining or standard walking program. Walking duration increased from 10 to 30 minutes as feedback faded over eight sessions. Gait retraining participants received real-time biofeedback to reduce peak tibial acceleration by 20%. Feasibility criteria included rates of recruitment, enrollment, and retention and number of adverse events. Knee pain and overground impact loading were assessed at baseline and one week after the last treadmill session. Analysis of covariance models compared group differences in peak tibial acceleration, pain, and impact loading after the walking program, controlling for baseline values. Most feasibility criteria were met. From 2019 to 2023, 867 individuals were screened (~22 individuals per month), and 46 were enrolled and randomized (n = 23 per group). No adverse events were identified. Peak tibial acceleration reduced by 0.13g and 0.09g (gravitational equivalents) for the gait retraining and standard walking groups, respectively. Greater reductions in pain were observed for the standard walking group compared to the gait retraining group. Changes in impact loading were not significant in either group. No between-group differences were observed for peak tibial acceleration, knee pain, or impact loading. A full-scale randomized clinical trial is feasible with modification. However, gait retraining to reduce peak tibial acceleration was no more effective than a standard walking program for reducing knee pain and impact loading.

Gait retraining is a strategy to manage altered loading patterns and pain characteristic of knee osteoarthritis. Lower walking cadence is associated with higher knee joint loading, vertical ground reaction forces, and risk for cartilage worsening. Therefore, we determined the acute effects of increasing walking cadence on measures of lower extremity loading and knee pain in knee osteoarthritis. Twenty-five participants with knee osteoarthritis (age = 62.5 ± 7.2; 76.0 % female) walked at fixed speed on an instrumented treadmill from which baseline cadence was measured. Five, randomized experimental cadence conditions (2 %, 4 %, 6 %, 8 %, or 10 % over baseline cadence) were completed. Real-time auditory and visual feedback on cadence was provided while kinematics and ground reaction forces were sampled. Linear mixed effects models evaluated the effect of cadence on knee adduction and flexion moment peaks and impulses, impact loading metrics (vertical ground reaction force impact peak, vertical average and instantaneous loading rates), and knee pain. Increasing cadence by 2-10 % did not significantly change knee adduction moment peaks or impulse. Peak knee flexion moment increased by 3-32 % and knee flexion moment impulse reduced by 2-9 % with increases in cadence, but these results were not significant (peak knee flexion moment, p = 0.070; knee flexion moment impulse, p = 0.085). Increasing cadence significantly increased the vertical impact peak (p < 0.001), and the vertical average (p = 0.010), and instantaneous (p = 0.007) loading rates. Small increases in cadence at a fixed gait speed does not significantly change surrogate measures of knee joint loading or pain, but does increase measures of impact loading.

As the lower extremity is a linked-joint system, the contribution of movements at the hip and ankle, in addition to the knee, to gait patterns should be considered for persons with knee osteoarthritis (OA). However, the relationships of joint coordination variability to OA symptoms, particularly knee pain, and joint loading is unknown. The purpose of this study was to determine the relationship of joint coordination variability to knee pain severity and joint loading in persons with knee OA. Thirty-four participants with knee OA underwent gait analysis. Vector coding was used to assess coordination variability during the early, mid, and late stance phase. Hip-knee coupling angle variability (CAV) during midstance was associated with Knee Injury and Osteoarthritis Outcome Score (KOOS) pain (r = -0.50, p = 0.002) and Visual Analog Scale pain (r = 0.36, p = 0.04). Knee-ankle CAV during midstance was associated with KOOS pain (r = -0.34, p = 0.05). Hip-knee CAV during early and midstance were associated with knee flexion moment (KFM) impulses (r = -0.46, p = 0.01). Knee-ankle CAV during early and midstance were associated with peak KFM (r = -0.51, p < 0.01; r = -0.70, p < 0.01). Moreover, knee-ankle CAV during early, mid, and late stance phase were associated with KFM impulses (r = -0.53, p < 0.01; r = -0.70, p < 0.01; r = -0.54, p < 0.01). These findings suggest that joint coordination variability may be a factor that influences pain and knee joint loading in persons with knee OA. Statement of Clinical Significance: Movement coordination of the hip, knee, and ankle should be considered in the clinical management and future research related to knee OA.

Increased knee joint loading during walking is a risk factor for the development and progression of knee osteoarthritis (OA). Thus, treatments that aim to reduce loading during gait may improve outcomes. Gait retraining to reduce peak vertical tibial acceleration (i.e., PTA; a correlate of vertical impact loads) has been shown to reduce injury risk in runners. It is unknown if this type of gait retraining is effective in adults with knee OA. PURPOSE: Determine the effect of a walking-based gait retraining program on impact loading and knee pain in adults with knee OA. METHODS: 21 adults with clinically defined knee OA participated (age = 63.9 ± 6.9; 76.2% female; BMI = 28.9 ± 5.8 kg/m2). Participants completed a walking-based gait retraining program on a treadmill with an inertial measurement unit secured to the distal antero-medial tibia to provide feedback on PTA. Baseline PTA was determined during the first visit. During 8 treatment sessions, walk time was increased from 10-30 minutes. Real-time auditory feedback was given when PTA exceeded 80% of baseline PTA. Feedback was gradually faded during the last 4 sessions. PTAs were averaged for 1 minute for the first and last sessions. A knee pain severity scale (0-100) and an overground gait assessment were completed before and after the retraining program. Measures of impact loading, i.e., vertical ground reaction force impact peak (VIP) and average loading rate (VALR), were averaged across 5 steps. Paired t-tests were used to compare PTA, impact loading, and knee pain for the more symptomatic knee before and after the retraining program. RESULTS: Following gait retraining, measures of PTA, impact loading, and knee pain decreased (Table 1). CONCLUSION: A gait retraining program aimed at decreasing PTA was associated with reductions in loading and knee pain. This suggests that this type of gait retraining may be a beneficial adjunct to the treatment of knee OA. FUNDING SOURCE: NIH/NIAMS AR070913

Purpose: As the lower extremity is a linked-joint system, the contribution of movements at the hip and ankle, in addition to the knee, to gait patterns should be considered for persons with knee osteoarthritis (OA). Less joint coordination variability could be a risk factor for lower extremity joint pathology. The external knee adduction and flexion moments are surrogate measures of knee joint loading and associated with OA progression. However, it is unknown if lower extremity joint coordination variability is related to knee joint loading.

Purpose: Greater knee joint loading during walking is a well-established risk factor for OA progression, pain, and functional worsening. Individuals who walk with a low cadence (low number of steps taken per minute) have greater loading and an increased risk of cartilage worsening compared to individuals who walk with a high cadence. However, no studies to date have investigated the relation of cadence to pain progression in those with knee OA. The aim of this study was to determine the association of walking cadence to incident and worsening knee pain over 2 years in adults with or at risk for knee OA.

Background: Higher impact loading during walking is implicated in the pathogenesis of knee osteoarthritis. Accelerometry enables the measurement of peak tibial acceleration outside the laboratory. We characterized the relations of peak tibial acceleration to knee pain and impact loading during walking in adults with knee osteoarthritis.Methods: Adults with knee osteoarthritis reported knee pain then walked at a self-selected speed on an instrumented treadmill for 3 min with an ankle-worn inertial measurement unit. Ground reaction forces and tibial acceleration data were sampled for 1 min. Vertical impact peaks, and average and peak instantaneous load rates were determined and averaged across 10 steps. Peak tibial acceleration was extracted for all steps and averaged. Pearson's correlations and multiple linear regression analyses assessed the relation of peak tibial acceleration to pain and impact loading metrics, independently and after controlling for gait speed and pain. Findings: Higher peak tibial acceleration was associated with worse knee pain (r = 0.39; p = 0.01), and higher vertical average (r = 0.40; p = 0.01) and instantaneous (r = 0.46; p = 0.004) load rates. After adjusting for gait speed and pain, peak tibial acceleration was a significant predictor of vertical average (R2 = 0.33; p = 0.003) and instantaneous (R2 = 0.28; p = 0.02) load rates, but not strongly associated with vertical impact peak.Interpretations: Peak tibial acceleration during walking is associated with knee pain and vertical load rates in those with knee osteoarthritis. Clinicians can easily access measures of peak tibial acceleration with wearable sensors equipped with accelerometers. Future work should determine the feasibility of improving patient outcomes by using peak tibial acceleration to inform clinical management.

Objective The purpose of this study was to describe adverse events (AEs) and dropouts (DOs) in randomized controlled trials of therapeutic exercise for hip osteoarthritis (HOA) and to identify whether Consolidated Standards of Reporting Trials (CONSORT) guidelines were followed. Methods The Cochrane Library, Embase, PubMed, and CINAHL databases were searched. Randomized controlled trials of therapeutic exercise for HOA published in English from January 1, 1980 to August 1, 2020 were included. Studies were excluded if other interventions were provided, if participants had previous hip arthroplasty, or if AEs and DOs for HOA participants were not reported separately. The internal validity of each study (Physiotherapy Evidence Database [PEDro] scoring) was assessed, participant and intervention characteristics were extracted, and the existence of a clear statement and reasons for AEs and DOs was reported. Descriptive statistics characterized results. Data heterogeneity prohibited the use of meta-analysis. Results Fourteen studies (mean PEDro score=7.4; range=6-10) from 10 countries were included, with 707 participants exercising. Exercise intensity was unspecified in 72.2% of exercise arms. Six studies (42.9%) included a statement of AEs, and 32 AEs were reported. All studies had a DO statement, but 29.0% of DOs occurred for unknown reasons. Six studies (42.9%) gave reasons for DOs that could be classified as AEs in 9 participants; 41 participants (5.8%) experienced exercise-related AEs. Conclusion Reports of AEs were inconsistent, some DOs were potentially misclassified, and primary components of exercise interventions were frequently unreported. Despite these limitations, the overall low number of nonserious AEs suggests that the exercise-related risk of harm is minimal for individuals with HOA. Impact Understanding the risk of harm associated with exercise for HOA can better inform safe dosing of exercise, clinical implementation, and replicability. Informative, consistent reporting of AEs, DOs, and exercise is needed. Greater use of the CONSORT harms-reporting checklist is warranted.

Background Therapeutic exercise is recommended as a core treatment for hip osteoarthritis (HOA). Whilst it is widely accepted that exercise can improve pain and disability, optimal type and dose of exercise are yet to be agreed upon. This may, in part, be attributed to the wide variation and inadequate reporting of interventions within the literature. This study evaluates the quality of intervention reporting among trials of therapeutic exercise in HOA. Methods Randomised controlled trials (RCTs) were sourced in a systematic review, completed in August 2020. Two raters independently used the Template for Intervention Description and Replication (TIDieR) and Consensus on Exercise Reporting Template (CERT) to evaluate intervention reporting. Correlations between quality assessment scores and CERT and TIDieR scores evaluated the relationship between internal validity and external applicability. The year of publication was compared to the quality of reporting scores. Results Fourteen RCTs were included in the analysis. On average, studies were awarded 9.43 ± 1.95 out of 12 points for the TIDieR checklist (range 4–12) and 13.57 ± 4.01 out of 19 points for the CERT (range 5–19). Pearson’s correlation coefficient suggested that the quality of reporting had improved over time and that there was a fair, positive relationship between internal validity and external applicability. Discussion Whilst the quality of intervention reporting is improving, many RCTs of therapeutic exercise in HOA lack the detail necessary to allow accurate evaluation and replication. Researchers are encouraged to utilise the standardised reporting guidelines to increase the translation of effective interventions into clinical practice.

Purpose: Several professional rheumatology, osteoarthritis, and health organizations recognize exercise as an effective approach to manage knee osteoarthritis (OA). Strength training exercises are often recommended, given that lower extremity weakness is a modifiable risk factor for the incidence and progression of knee OA. While the proliferation of wearable technology has facilitated our understanding of physical activity (e.g., unstructured energy expenditure above resting levels), less is known about the long-term impact of exercise (structured and repeated energy expenditure above resting levels), and strength training in particular, on physical function. Quantifying longitudinal patterns of physical function associated with strength training participation may facilitate our understanding of the broader impacts of this particular exercise mode and better inform tailored exercise prescription for adults with knee OA. Therefore, the aim of this study was to determine the relation of self-reported strength training, accounting for moderate-vigorous aerobic activity, to trajectories of objectively measured and self-reported physical function over 7 years. Methods: Participants were included from the Multicenter Osteoarthritis (MOST) study. MOST is a NIH-funded, longitudinal cohort study of individuals with or at risk of developing knee OA. Strength training participation status: Participants completed the Physical Activity Scale for the Elderly (PASE) questionnaire at baseline from which level of strength training participation was obtained. Participants were asked “Over the past 7 days, how often did you do any exercise specifically to increase muscle strength and endurance, such as lifting weights or pushups, etc.?”. Strength training participation was then categorized into ‘no participation’ or ‘any participation,’ with ‘any’ participation defined by reporting at least 1-2 days/week of strength exercise. Physical function: 20-meter walk test (seconds), repeated chair-stand test (seconds to complete five repeated chair stands), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function subscale (higher scores represent low function) were used to assess physical function at baseline, 30-, 60-, and 84-months. Statistical analysis: Trajectories of physical function were identified using group-based trajectory modeling. Trajectory group sizes of at least 5% of the study population, and Bayesian Information Criterion, were used to select the optimal number of trajectory groups. We calculated posterior probabilities to determine the proportion of individual trajectories that fit within the group trajectories. Logistic regression was used to determine the association between strength training participation status at baseline and trajectories of changes in physical function. Multinomial logistic regression was used when more than two trajectories were identified. Analyses were adjusted for age, sex, BMI, radiographic knee OA, self-reported moderate-vigorous aerobic activity (never versus any), and knee pain severity. Odds ratios with 95% confidence intervals were determined for each analysis. Results: 3,026 MOST participants reported strength training participation status at baseline. The mean age and BMI were 61.9 (8.1) years and 30.3 (5.8) kg/m2, respectively; 58.3% female. The proportion of participants in the “Never” versus “Any” strength training participation categories were 57.7% and 42.3%, respectively. Three stable trajectories, neither improving or declining over 84 months, were identified for self-report physical function (higher WOMAC scores reflect low function): high function [mean (SD) = 3.3 (3.4)], intermediate function [mean (SD) = 14.4 (8.3)], and low function [mean (SD) = 31.7 (9.6)] (Fig. 1). Compared to participants who reported strength training participation, those with did not strength train had 0.9 (0.7, 1.1) and 1.3 (1.0, 1.8) times the odds of being in the intermediate and low function trajectories, respectively, compared to being in the high function trajectory. We identified two trajectories for the objective measures of physical function over 84 months: stable and worsening (Fig. 1). The stable trajectory for gait speed and chair stands included 90% and 86.5% of participants, while the worsening trajectories included 10% and 14.5%, respectively. Compared to participants who reported strength training participation, those who did not strength train had 1.6 (1.1, 2.3), and 1.8 (1.3, 2.4) times the odds of being in the worsening gait speed and chair stands trajectories, respectively. The mean posterior probabilities of classifying participants to each self-report and objective physical function trajectory ranged from 90.4% to 98.9%, indicating excellent model fit. Conclusions: Participants who engage in strength training exercise are more likely to have and maintain higher levels of physical function over 7 years independent of self-reported level of moderate-vigorous aerobic activity.

Objective:This study aims to 1) determine the feasibility of conducting a full-scale randomized controlled trial (RCT) evaluating the efficacy of a gait retraining program on decreasing knee pain and impact loading in people with knee osteoarthritis, and 2) provide an estimate of treatment effects for a gait retraining program compared to a traditional walking program.Methods:Forty individuals with knee osteoarthritis will be enrolled in this randomized, double-blind, feasibility trial with two parallel groups. Participants will be randomly allocated to a gait retraining program aimed to decrease peak axial acceleration of the lower leg (i.e., tibia) by 20% or a traditional walking program. Both programs involve 8 sessions of walking on a treadmill. Feasibility will be assessed with recruitment, enrollment, and retention rates, and number of adverse events and unanticipated problems. Treatment effects will be estimated with measures of knee pain and impact loading collected at baseline, follow-up (<1 week post-intervention), and retention (≥1 month post-intervention) visits. Knee pain will be evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index and impact loading will be measured during walking with three-dimensional motion analysis.Conclusion:Findings of this study will inform the feasibility of a full-scale RCT investigating the efficacy of a gait retraining program for people with knee osteoarthritis.Trial registration:(NCT04148807).

Wheelchair users as a group are considered to be sedentary and among the least fit individuals. [1] It is well known that sedentary lifestyle adversely impacts health. [2-4] To promote health, research has focused on physical exercise interventions to increase physical activity (PA) or decrease sedentary time throughout the day. [5] There are also multiple PA guidelines that recommend the intensity and duration of PA for people with spinal cord injury (SCI) who often rely on wheelchairs for mobility. [6] Traditionally, self-report surveys are often used as surveillance tools to track habitual PA in the community, but they are limited by burdens of recall, lack of responses, and inaccuracy. [7] With the proliferation and cost reduction of wearable devices, accelerometerbased sensors are increasingly used for users to track their own PA behaviors and for researchers to examine the association of PA behaviors and health indicators.

We developed a 3D vision-based semi-autonomous control interface for assistive robotic manipulators. It was implemented based on one of the most popular commercially available assistive robotic manipulator combined with a low-cost depth-sensing camera mounted on the robot base. To perform a manipulation task with the 3D vision-based semi-autonomous control interface, a user starts operating with a manual control method available to him/her. When detecting objects within a set range, the control interface automatically stops the robot, and provides the user with possible manipulation options through audible text output, based on the detected object characteristics. Then, the system waits until the user states a voice command. Once the user command is given, the control interface drives the robot autonomously until the given command is completed. In the empirical evaluations conducted with human subjects from two different groups, it was shown that the semi-autonomous control can be used as an alternative control method to enable individuals with impaired motor control to more efficiently operate the robot arms by facilitating their fine motion control. The advantage of semi-autonomous control was not so obvious for the simple tasks. But, for the relatively complex real-life tasks, the 3D vision-based semi-autonomous control showed significantly faster performance. Implications for Rehabilitation A 3D vision-based semi-autonomous control interface will improve clinical practice by providing an alternative control method that is less demanding physically as well cognitively. A 3D vision-based semi-autonomous control provides the user with task specific intelligent semiautonomous manipulation assistances. A 3D vision-based semi-autonomous control gives the user the feeling that he or she is still in control at any moment. A 3D vision-based semi-autonomous control is compatible with different types of new and existing manual control methods for ARMs.

A 6-month pilot study explored the effects of a yoga program on the physical activity (PA) level of overweight or obese sedentary adults. Fourteen community-dwelling overweight or obese sedentary adults participated in a 6-month program (2-month yoga program and 4-month follow-up) delivered by two types of instruction [the direct guidance of an instructor (face-to-face group) vs. the self-learning method of using a DVD (DVD group)]. Measurements included program adherence (class attendance and home practice; min/week) and level of PA [metabolic equivalent (MET)-hour/week] at baseline, 2, 4 and 6 months. Descriptive statistics and nonparametric tests were used to describe the sample and examine differences by group and time. There were no significant differences in demographic variables by group assigned. Participants showed significant PA changes from baseline to each measurement point. The direct guidance of an instructor was preferred over the self-learning method. At each time interval, the DVD group showed higher levels of PA than the face-to-face group; the only difference that achieved statistical significance occurred at 4 months. The PA level significantly changed over 6 months in the DVD group, but not in the face-to-face group. The results indicate that a yoga program may be utilized as a 'stepping-stone' toward regular exercise among overweight sedentary adults. Research with a larger sample is needed to further evaluate the effects of the program on the level of PA among this population.

BACKGROUND: This study examined the relationship between actual body weight and self-perceived weight, and how perception of one's weight affects weight management behaviors among US adolescents.METHODS: Adolescents ages 16-19 years with objectively-measured weight and height and self-reported perception of weight, weight-loss efforts, and health-related behaviors (N = 642) from the 2009-2010 National Health and Nutritional Examination Survey (NHANES) were included. Sociodemographic variables, body mass index percentile, weight perception, weight-loss efforts, and health-related behaviors were examined using Wald chi-square, Student's t test, analysis of variance, and logistic regression.RESULTS: Approximately 15% were overweight, and 20% were obese; 26% inaccurately perceived their weight. Ethnic minority groups displayed higher rates of overweight and obesity. Overweight adolescents had a higher rate of inaccurate weight perception than obese adolescents. More girls correctly perceived their weight status than boys. Nearly 25% had tried to lose weight during the past year. Among overweight and obese adolescents, accurate weight perception was significantly and positively related to weight-loss efforts after controlling for sociodemographic variables and actual weight.CONCLUSIONS: Accurate body weight perception is a significant factor in adolescents' weight-loss efforts. Targeting counseling for body weight perception and weight management toward boys and overweight adolescents may impact obesity in this age group.