An intervention to decrease sedentary behavior in older adults: A secondary analysis of a randomized controlled trial.

Background: Sedentary behaviors are associated with adverse health outcomes in older adults. The feasibility of behavioral interventions in this population is unclear. Methods: In the Sit Less, Interact, Move More (SLIMM) trial of 106 participants who had obesity, those randomized to the SLIMM intervention (N = 54) were instructed to replace sedentary activities with stepping. An accelerometer was used to measure physical activity. In this secondary analysis, mixed effect models were used to examine the effects of the SLIMM intervention on sedentary and stepping durations and steps/day by age (<70 and ≥ 70 years). Results: Mean ages in the <70 years (N = 47) and ≥70 years (N = 59) groups were 58 ± 11 and 78 ± 5. In the older subgroup, compared to standard-of-care (N = 29), the SLIMM intervention (N = 30) significantly increased stepping duration (13, 95%CI 1-24 min/d, p = 0.038) and steps per day (1330, 95% CI 322-2338, p = 0.01) and non-significantly decreased sedentary duration by (28,95% CI -61-5 min/d, p = 0.09). In the age <70 subgroup, there was no separation between the standard of care (N = 23) and SLIMM (N = 24) groups. Discussion: In older adults who had obesity, SLIMM intervention significantly increased stepping duration and steps per day. Interventions targeting sedentary behaviors by promoting low intensity physical activity may be feasible in this population.

Predicting hospitalization from real-world measures in patients with chronic kidney disease: A proof-of-principle study.

Objective: To investigate if in-clinic measures of physical function and real-world measures of physical behavior and mobility effort are associated with one another and to determine if they predict future hospitalization in participants with chronic kidney disease (CKD). Methods: In this secondary analysis, novel real-world measures of physical behavior and mobility effort, including the best 6-minute step count (B6SC), were derived from passively collected data from a thigh worn actigraphy sensor and compared to traditional in-clinic measures of physical function (e.g. 6-minute walk test (6MWT). Hospitalization status during 2 years of follow-up was determined from electronic health records. Correlation analyses were used to compare measures and Cox Regression analysis was used to compare measures with hospitalization. Results: One hundred and six participants were studied (69 ± 13 years, 43% women). Mean ± SD baseline measures for 6MWT was 386 ± 66 m and B6SC was 524 ± 125 steps. Forty-four hospitalization events over 224 years of total follow-up occurred. Good separation was achieved for tertiles of 6MWT, B6SC and steps/day for hospitalization events. This pattern persisted in models adjusted for demographics (6MWT: HR = 0.63 95% CI 0.43-0.93, B6SC: HR = 0.75, 95% CI 0.56-1.02 and steps/day: HR = 0.75, 95% CI 0.50-1.13) and further adjusted for morbidities (6MWT: HR = 0.54, 95% CI 0.35-0.84, B6SC: HR = 0.70, 95% CI 0.49-1.00 and steps/day: HR = 0.69, 95% CI 0.43-1.09). Conclusion: Digital health technologies can be deployed remotely, passively, and continuously to collect real-world measures of physical behavior and mobility effort that differentiate risk of hospitalization in patients with CKD.

Recovery Curve for Patient Reported Outcomes and Objective Physical Activity After Primary Total Knee Arthroplasty-A Multicenter Study Using Wearable Technology.

BACKGROUND: This study aimed to describe the trajectory of recovery based on patient-reported outcomes (PROs) and objective metrics of physical activity measures over the first 12 months post-total knee arthroplasty (TKA). METHODS: In total, 1,005 participants who underwent a primary unilateral TKA surgery between November 2018 and September 2021 from a multisite prospective study were analyzed. Generalized estimating equations were used to evaluate PROs and objective physical activity measures over time. RESULTS: All Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), EuroQol-5D (EQ-5D), and steps per day scores were greater than preoperative scores (P < .05). The flights of stairs per day, gait speed, and walking asymmetry all declined at 1 month (all, P < .001). However, all subsequent scores improved by 6 months (all, P < .01). The greatest clinically important differences from previous visit in KOOS JR (ß = 18.1; 95% Confidence Interval (CI) = 17.2, 19.0), EQ-5D (ß = 0.11; 95% CI = 0.10, 0.12), steps per day (ß = 1,169.3; 95% CI = 1,012.7, 1,325.9), gait speed (ß = -0.05; 95% CI = -0.06, -0.03), and walking asymmetry (ß = 0.00; 95% CI = -0.03, 0.03) were observed at 3 months. CONCLUSION: The KOOS JR, EQ-5D, and steps per day measures showed earlier improvements than other physical activity metrics, with the greatest magnitude of improvement within the first 3 months post-TKA. The greatest magnitude of improvement in walking asymmetry was not observed until 6 months, while gait speed and flights of stairs per day were not observed until 12 months. This data may further help provide expectation setting information to patients before surgery, and may aid in identifying outliers to the normal recovery curve who may benefit from targeted interventions.

Patient-reported outcomes measurement information system physical function and knee injury and osteoarthritis outcome score relationship on performance measures in people undergoing total knee arthroplasty.

PURPOSE: Primary purpose was to identify relationships between performance-based measures onto both computerized adaptive testing [Physical Function-Computer Adaptive Testing (PF-CAT)] and joint-specific legacy [Knee injury and Osteoarthritis Outcome Score-Activities of Daily Living (KOOS-ADL)] instruments pre- and 12-month post-TKA. METHODS: The PF-CAT and KOOS-ADL were identified as outcomes and performance on the 40-m fast-paced walking test, stair climb test and chair stand test were identified as predictors. Linear regression was used for all comparisons after adjusting for confounders. RESULTS: Sixty-eight people with TKA (56.7% male) were tested. Better scores on the 40-m fast-paced walking (KOOS-ADL, p = 0.02), stair climb (KOOS-ADL, p = 0.05) and chair stand (KOOS-ADL, p < 0.01) associated with better self-reported scores pre-TKA. Better scores on the 40-m fast-paced walking (PF-CAT, p = 0.05; KOOS-ADL, p = 0.01), stair climb (KOOS-ADL, p < 0.01), chair stand (PF-CAT, p < 0.01) and range of motion (KOOS-ADL, p = 0.02) were associated with better self-reported scores 12-month post-TKA. Decrease knee range of motion related to poorer 40-m fast-paced walking (p = 0.01) and stair climb (p = 0.03) scores pre-TKA. Quadriceps weakness related to poorer 40-m fast-paced walking (p = 0.04) score pre-TKA. CONCLUSION: Self-reported instruments are a moderate, but inconsistent surrogate to performance-based measures pre- and post-TKA. Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the recovery analysis of people undergoing TKA.Implications for RehabilitationMonitoring the trajectory of pre- to post-total knee arthroplasty (TKA) physical function is important as it directly relates to mortality, morbidity and poorer quality of life in older adults.Both self-reported and performance-based measures of physical function are used to determine progress in recovery for patients pre- and post- TKA.This study provides evidence that perceived physical function measures are a moderate, but an inconsistent, surrogate to objective physical function measures pre- and post-TKA.Joint specific deficits in knee range of motion and quadriceps strength were weakly associated with deficits in function measures pre-TKA, but no association was observed 12-month post-TKA.Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the complete recovery analysis of people undergoing TKA.

Factors Associated with Trajectories of Physical Activity Over 8 Years in Knee Osteoarthritis.

OBJECTIVE: The aim of the study was to investigate (1) trajectories of physical activity (PA) over 96 months and (2) study to what extent knee pain, muscle strength, physical function, and radiographic disease were associated with PA trajectories in adults with or at risk of knee osteoarthritis (KOA). METHODS: Using the Osteoarthritis Initiative (OAI) database, we described PA trajectories with the Physical Activity Scale for the Elderly (PASE) over 96 months. Knee pain was categorized into three groups: "no pain" [visual numeric pain rating scale (VAS=0)], "little to some pain" (VAS=1-3), or "moderate to severe pain" (VAS ≥ 4). Knee extensor strength was classified into high [>16.21 (men) and >10.82 (women) N/kg/m2 ] and low [12 seconds) and fast (<12 seconds) groups. Radiographic disease was classified as present [Kellgren-Lawrence (KL) ≥2] or absent (KL grade <2) of KOA. RESULTS: Among 3755 participants (age 61.0 ± 9.0 years, body mass index 28.5±4.8 kg/m2 , 58% female), we identified three trajectories: sedentary PA with slow decline (44.3%), low PA with slow decline (41.3%), and high PA with slow decline (14.4%). Poorer gait speed (OR: 2.32; 95% CI: 1.71-3.16), chair stand time (OR: 1.45; 95% CI: 1.07-1.96), and knee extensor strength (OR: 1.35; 95% CI: 1.03-1.76), but not pain or radiographic disease, were associated with PA trajectory of sedentary PA with slow decline. CONCLUSION: Physical function and strength, but not pain and radiographic disease, were associated with a trajectory of decline in PA among adults with or at risk of KOA.

The validity and reliability of the OneStep smartphone application under various gait conditions in healthy adults with feasibility in clinical practice.

OBJECTIVE: Primary purpose of this study was to determine the validity and reliability of the OneStep smartphone application in healthy adults. Secondary purpose was to determine the feasibility of measuring gait dysfunction, limitation in spatiotemporal characteristics, longitudinally in patients following total hip or knee arthroplasty. METHODS: First objective, 20 healthy adults (mean age, 42.3 ± 19.7 years; 60% males; mean body mass index, 29.0 ± 5.2 kg/m2) underwent gait analysis under four gait conditions (self-selected gait speed, fixed gait speed at 0.8 m/s, fixed gait speed at 2.0 m/s and self-selected gait speed with dual task) for the validity and reliability of the smartphone to the motion laboratory. Reliability was determined by intraclass correlation coefficients. Validity was determined by Pearson correlations. Agreement was assessed by the Bland-Altman method. Second objective, 12 additional patients with total hip or knee arthroplasty (mean age, 58.7 ± 6.5 years; 58% males; mean body mass index, 28.9 ± 5.8 kg/m2) were measured at 2- and 10 weeks postoperatively. The smartphone application was used to evaluate change in gait dysfunction over time within the patients' own environment using paired t test. RESULTS: The smartphone application demonstrated moderate-to-excellent intraclass correlation coefficients for reliability between-system (ICC range, 0.56-0.99), -limb (ICC range, 0.62-0.99) and -device (ICC range, 0.61-0.96) for gait analysis of healthy adults. Pearson correlations were low-to-very high between methods (r range, 0.45-0.99). Bland-Altman analysis revealed relative underestimation of spatiotemporal variables by the smartphone application compared to the motion system. For patients following total hip or knee arthroplasty, gait analysis using the OneStep application demonstrated significant improvement (p < 0.001, Cohen's d > 0.95) in gait dysfunction between 2- and 10 weeks postoperatively. CONCLUSION: The smartphone application can be a valid, reliable and feasible alternative to motion laboratories in evaluating deficits in gait dysfunction in various environments and clinical settings.

Lower Limb Extension Power is Associated With Slope Walking Joint Loading Mechanics in Older Adults.

Fall-related injuries are associated with muscle weakness and common during slope walking in older adults. However, no study has evaluated the relationship between muscle weakness, measured by maximal lower limb extension power, and older adults' ability to navigate slope walking for a better understanding of fall prevention. Therefore, the purpose of this study was to investigate the association between maximal lower limb extension power and joint mechanics during slope walking. Fifteen healthy older adults were tested. Lower limb extension power was measured using the Leg Extension Power Rig. Kinematic and kinetic analysis was performed during level (0°), incline (10°), and decline (10°) slope walking. Greater maximal lower limb extension power was significantly (p < .050; Cohen's f2 > 0.35) associated with multiple kinetic and kinematic joint mechanic variables across stance phase of the gait cycle during level, incline, and decline walking. These findings will allow clinicians to better educate patients and develop interventions focused on fall prevention and improving functional mobility in older adults.

Knee biomechanics and contralateral knee osteoarthritis progression after total knee arthroplasty.

BACKGROUND: Despite the success rate of Total Knee Arthroplasty (TKA), many patients undergo contralateral TKA. It is possible that altered gait mechanics after unilateral TKA play a role in the progression of contralateral OA progression. RESEARCH QUESTION: The purpose of this study was to identify biomechanical predictors of radiographic OA progression in the contralateral (non-surgical) knee after unilateral (primary/initial) TKA. In addition, this study quantified for patients who had contralateral OA progression. METHODS: Biomechanical outcomes were collected 6-24 months after unilateral primary TKA and were used to predict changes in contralateral OA severity at follow-up. Participants were divided into "Progressor" and "Non-Progressor" groups based on changes in Kellgren-Lawrence (KL) OA grade and Joint Space Width (JSW) between baseline and follow-up testing sessions. Biomechanical factors during walking were peak knee adduction moment, knee flexion/extension excursions, knee angle at initial foot contact, and peak knee flexion/extension. Multiple independent t-tests were used to examine the magnitude of differences in biomechanical variables between the groups. Logistic regression was used to examine the association between the biomechanical predictors and change in KL scores and JSW. RESULTS: The mean time between surgery and follow-up x-rays was 8.8 (2.4) years. Of 40 participants, 62.5-78% had contralateral radiographic knee OA progression by follow-up. There were no significant differences in the biomechanical variables between groups. For the regression analysis, none of the biomechanical variables were found to be predictors for contralateral OA progression. SIGNIFICANCE: Although abnormal biomechanics are known risk factors for primary knee OA, it is possible that the mechanisms that result in OA progression of the contralateral limb are different than primary knee OA progression. Future work should evaluate other objective measures of OA progression and determine if cumulative measures of joint loading are related to OA worsening.

Trunk movement compensation identified by inertial measurement units is associated with deficits in physical performance, muscle strength and functional capacity in people with hip osteoarthritis.

BACKGROUND: Trunk movement compensation characterized as ipsilateral trunk lean and posterior rotation with respect to pelvis during stance phase of walking is common in people with hip osteoarthritis and a biomarker of deficits in physical function in older adults. However, the relationship between trunk movement compensation on deficits in physical performance, muscle strength and functional capacity is unknown. METHODS: A cross-sectional study design was used. Two inertial measurement units were used to assess trunk movement compensation during the six-minute-walk-test. Knee extension, knee flexion and hip abduction strength were measured using hand-held dynamometer. Multivariate regression models, controlling for self-reported hip pain, were used to regress trunk movement compensation onto six-minute-walk-test and muscle strength measures. Pairwise t-tests were used to evaluate the difference trunk movement compensation has on functional capacity by comparing the first and last minute of the six-minute-walk-test. FINDINGS: Thirty-five participants (63.3 ± 7.4 years, 57% male, 28.6 ± 4.5 kg/m2) were enrolled. Greater trunk movement compensation was related to poorer six-minute-walk-test (p = 0.03; r = -0.46). Greater hip abduction weakness was related to increased trunk movement compensation in both the sagittal (p = 0.05; r = -0.44) and frontal (p = 0.04; r = -0.38) planes. Participants demonstrated greater frontal plane trunk movement compensation during the last minute compared to the first minute of the six-minute-walk-test (p < 0.01). INTERPRETATION: Trunk movement compensation, identified by inertial measure units, is a clinically relevant measure and has a moderate-to-strong relationship on deficits in physical performance, muscle strength and functional capacity. Inertial measurement units can be used as a practical means of measuring movement quality in the clinical setting.

Targeting Sedentary Behavior in CKD: A Pilot and Feasibility Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: We tested the feasibility of reducing sedentary behavior common in CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We carried out a Sit Less, Interact, Move More intervention in a 24-week parallel-group, randomized controlled trial in patients with stages 2-5 CKD. In the intervention group (n=54), accelerometry performed at baseline and repeated every 4 weeks was used to develop and monitor adherence to individualized plans targeting sedentary and stepping durations. The control group (n=52) was provided national physical activity recommendations; accelerometry was performed at baseline and every 8 weeks. Between-groups changes from baseline to the average follow-up values at weeks 8, 16, and 24 of the sedentary and stepping durations were the coprimary end points. RESULTS: The mean age was 69±13 years. Fourteen percent were on dialysis or received a kidney transplant. Eight percent of the control group and 17% of the intervention group were lost to follow-up. Sedentary and stepping durations did not change in the control group. Within the intervention group, the maximum decrease in sedentary duration (-43; 95% confidence interval, -69 to -17 min/d) and increase in stepping duration (16; 95% confidence interval, 7 to 24 min/d) and the number of steps per day (1265; 95% confidence interval, 518 to 2012) were seen at week 20. These attenuated at week 24. In mixed effects models, overall treatment effects between groups on sedentary (-17; 95% confidence interval, -43 to 8 min/d) and stepping (6; 95% confidence interval, -3 to 15 min/d) durations and the number of steps per day, a secondary end point (652; 95% confidence interval, -146 to 1449), were not significantly different. The intervention significantly reduced secondary end points of body mass index (-1.1; 95% confidence interval, -1.9 to -0.3 kg/m2) and body fat percentage (-2.1%; 95% confidence interval, -4.4% to -0.2%). CONCLUSIONS: It is feasible to reduce sedentary duration and increase stepping duration in patients with CKD, but these were not sustained. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: National Health and Nutrition Examination Survey (NHANES), NCT02970123.

Longitudinal study of knee load avoidant movement behavior after total knee arthroplasty with recommendations for future retraining interventions.

BACKGROUND: This study aimed to evaluate clinical and biomechanical changes in self-report survey, quadriceps strength and gait analysis over 3- and 6-months post-total knee arthroplasty (TKA) and confirm the immediate effects of two forms of kinetic biofeedback on improving inter-limb biomechanics during a physically demanding decline walking task. METHODS: Thirty patients with unilateral TKA underwent testing at 3- and 6-months following surgery. All underwent self-report survey, quadriceps strength and gait analysis testing. Patients were assigned to one of two types of biofeedback [vertical ground reaction force (vGRF), knee extensor moment (KEM)]. RESULTS: No decrease in gait asymmetry was observed in non-biofeedback trials over time (p > 0.05), despite significant improvements in self-report physical function (p < 0.01, Cohen d = 0.44), pain interference (p = 0.01, Cohen d = 0.68), numeric knee pain (p = 0.01, Cohen d = 0.74) and quadriceps strength (p = 0.01, Cohen d = 0.49) outcomes. KEM biofeedback induced significant decrease in total support moment (p = 0.05, Cohen f2 = 0.14) and knee extensor moment (p = 0.05, Cohen f2 = 0.21) asymmetry compared to using vGRF biofeedback at 6-months. vGRF biofeedback demonstrated significant decrease in hip flexion kinematic asymmetry compared to KEM biofeedback (p = 0.05, Cohen f2 = 0.18) at 6-months. CONCLUSION: Gait compensation remained similar from 3- to 6-months during a task requiring greater knee demand compared to overground walking post-TKA, despite improvements in self-report survey and quadriceps strength. Single session gait symmetry training at 6-month supports findings at 3-month testing that motor learning is possible. KEM biofeedback is more effective at immediately improving joint kinetic loading compared to vGRF biofeedback post-TKA.

A multi-center trial of exercise and testosterone therapy in women after hip fracture: Design, methods and impact of the COVID-19 pandemic.

BACKGROUND: Up to 75% of hip fracture patients never recover to their pre-fracture functional status. Supervised exercise that includes strength training can improve functional recovery after hip fracture. The role of testosterone replacement for augmenting the effects of exercise in older women after hip fracture is unknown. METHODS: The Starting Testosterone and Exercise after Hip Injury (STEP-HI) Study is a 6-month Phase 3 multicenter randomized placebo-controlled trial designed to compare supervised exercise (EX) plus 1% testosterone topical gel, with EX plus placebo gel, and with enhanced usual care (EUC). Female hip fracture patients age ≥ 65 years are being recruited from clinical centers across the United States. Participants are community dwelling and enrolled within 24 weeks after surgical repair of the fracture. The EX intervention is a center-based program of progressive resistance training. The EUC group receives a home exercise program and health education. Participants receive dietary counseling, calcium and vitamin D. The primary outcome is the Six Minute Walk Distance. Secondary outcomes include physical performance measures, self-reported function and quality of life, and dual energy x-ray absorptiometry measures of body composition and bone mineral density. RESULTS: Enrollment, interventions, and follow-up are ongoing. We describe the impact of the coronavirus disease 2019 pandemic on the trial, including modifications made to allow continuation of the interventions and outcome data collection using remote video and audio technology. CONCLUSIONS: Results from the STEP-HI study are expected to have important clinical and public health implications for management of the growing population of hip fracture patients.

Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty.

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post-TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self-reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross-sectionally at 6-24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (ß = .245, p = .044), knee extension moment (ß = .283, p = .049), and knee extension excursion (ß = .298, p = .038). Older age (ß = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (ß = -.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (ß = -.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (ß = .585, p < .001), knee extensor moment (ß = .481, p < .001), and knee flexion excursion (ß = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post-TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post-TKA.

Reliability, responsiveness, and validity of handheld dynamometry for assessing quadriceps strength in total knee arthroplasty.

PURPOSE: To determine the reliability, responsiveness, validity, and agreement of handheld dynamometry, relative to electromechanical dynamometry, for assessing quadriceps strength surrounding total knee arthroplasty. METHODS: Fifty-six patients (48% female) undergoing total knee arthroplasty were assessed prior to surgery and at 2 and 6 weeks following surgery. Maximum isometric quadriceps force was assessed at each time point by handheld dynamometry and electromechanical dynamometry. Within-session test-retest reliability was determined by intraclass correlation coefficient (ICC). Standard error of measurement and relative standard error (RSE) values were calculated. Standardized response means were used to describe responsiveness. Pearson's correlations examined construct validity. Agreement was assessed by the Bland-Altman method. RESULTS: Both handheld dynamometry and electromechanical dynamometry demonstrated excellent test-retest reliability (ICC >0.90) and RSE (<15%). Both methods were responsive, with large postoperative standardized response means of 1.57 (handheld dynamometry) and 1.37 (electromechanical dynamometry). Pearson's correlations were moderate to strong. The Bland-Altman analysis revealed underestimation of force by handheld dynamometry, although this effect was diminished in the early postoperative period. CONCLUSIONS: Our results suggest handheld dynamometry is a promising tool for monitoring quadriceps strength in patients pre- and post-total knee arthroplasty.IMPLICATIONS FOR REHABILITATIONThis study provides evidence of high reliability and responsiveness of handheld dynamometry for assessing quadriceps strength throughout a clinically relevant time frame for patients with total knee arthroplasty.There is construct validity of handheld dynamometry for measuring quadriceps strength, with moderate to high correlations between handheld dynamometry and electromechanical dynamometry, both pre- and post-total knee arthroplasty.Rehabilitation professionals should be aware that handheld dynamometry and electromechanical dynamometry do not agree in terms of the force measurement itself; particularly at higher force values, handheld dynamometry underestimates force output relative to electromechanical dynamometry.Overall, this study supports the use of handheld dynamometry for monitoring quadriceps strength in clinical settings for patient with total knee arthroplasty.

Physical activity, pain interference and comorbidities relate to PROMIS physical function in younger adults following total knee arthroplasty.

PURPOSE: To determine if preoperative physical and psychological health risk factors are influential on physical function and satisfaction scores in a cohort of relatively younger adults one year post-total knee arthroplasty. METHODS: Sixty-five patients were recruited pre- and one year post-total knee arthroplasty. Physical (i.e., body mass index, sex, physical activity level, number of comorbidities) and psychological (i.e., depression, expectations, pain inference) health risk factors were obtained pre-total knee arthroplasty and compared to Patient-Reported Outcomes Measurement Information System physical function computerized adaptive testing and satisfaction scores one year post-total knee arthroplasty. RESULTS: Bootstrap inclusion fraction methods were performed to compare the stability of each predictor variable prior to final regression analyzes. Poorer preoperative physical activity level (standardized regression coefficient = 0.37; p < 0.01), pain interference (standardized regression coefficient = -0.24; p = 0.03) and greater comorbidities (standardized regression coefficient = -0.27; p = 0.01) resulted in worse physical function scores one year post-total knee arthroplasty. Greater preoperative comorbidities (odds ratio = 0.63; p < 0.01) resulted in worse satisfaction scores one year post-total knee arthroplasty. No other predictor variable had any relationship on either clinical outcome (p > 0.05). CONCLUSION: Younger adults with greater comorbidities, lower physical activity level and higher pain interference scores preoperatively reported poorer functional recovery one year post-total knee arthroplasty. Understanding how preoperative status of younger adults undergoing total knee arthroplasty may lead to better improved surgical decision making and health care delivery for this vulnerable and growing patient subgroup.Implications for RehabilitationProjections estimate total knee arthroplasty in relatively younger adults (<65 years) will make up the majority of surgical procedures performed in the United States within the next two decades, however little is known in this patient population.This study provides evidence that relatively younger adults with greater comorbidities, lower physical activity level and higher pain interference scores preoperatively result in poorer functional recovery one year post-total knee arthroplasty.The results also suggest greater comorbidities identified preoperatively have the largest influence on one year satisfaction scores in younger adults post-total knee arthroplasty.Modifiable characteristics such as improving physical activity level, incorporating pain management strategies and reducing comorbidities preoperatively or adopting into postoperative rehabilitative care may influence the postoperative physical function and satisfaction scores in relatively younger adults undergoing total knee arthroplasty.

Movement asymmetry during low and high demand mobility tasks after dysvascular transtibial amputation.

BACKGROUND: Movement asymmetries between lower limbs are commonly exhibited by adults after transtibial amputation. However, the degree of movement asymmetry between low- and high-demand functional tasks remains unknown. METHODS: Kinematic and kinetic data were collected during overground walking (low-demand) and step ascent (high-demand) tasks for two groups: 1) persons with transtibial amputation and 2) healthy matched peers. Analysis of covariance was used to compare sagittal-plane peak knee moment and joint angle (primary) and hip and ankle moments and joint angles, vertical ground reaction force and impulse (secondary). FINDINGS: Within transtibial amputation group comparisons showed significantly greater between-limb asymmetry in peak knee moment (p < .01), vertical impulse (p < .01), peak vertical ground reaction force (p = .05), peak ankle angle (p < .01) and peak ankle moment (p < .01) with the step ascent task compared to overground walking. The transtibial amputation group had greater between-limb asymmetry during step ascent in peak knee moment (p < .01), vertical impulse (p < .01), peak vertical ground reaction force (p = .04) and peak ankle angle (p < .01) than healthy matched peers. During overground walking, the transtibial amputation group had greater between-limb asymmetry in peak vertical impulse (p = .05) and peak ankle moment (p < .01) than healthy matched peers. INTERPRETATION: Movement asymmetry is increased during step ascent compared to overground walking for adults with transtibial amputation. While the restoration of overground walking is the focus of post-amputation rehabilitation and prosthetic design, higher demand tasks should also be considered to maximize mobility for adults with transtibial amputation.

Reference chart for knee flexion following total knee arthroplasty: a novel tool for monitoring postoperative recovery.

BACKGROUND: Clinicians and patients lack an evidence-based framework by which to judge individual-level recovery following total knee arthroplasty (TKA) surgery, thus impeding personalized treatment approaches for this elective surgery. Our study aimed to develop and validate a reference chart for monitoring recovery of knee flexion following TKA surgery. METHODS: Retrospective analysis of data collected in routine rehabilitation practice for patients following TKA surgery. Reference charts were constructed using Generalized Additive Models for Location Scale and Shape. Various models were compared using the Schwarz Bayesian Criterion, Mean Squared Error in 5-fold cross validation, and centile coverage (i.e. the percent of observed data represented below specified centiles). The performance of the reference chart was then validated against a test set of patients with later surgical dates, by examining the centile coverage and average bias (i.e. difference between observed and predicted values) in the test dataset. RESULTS: A total of 1173 observations from 327 patients were used to develop a reference chart for knee flexion over the first 120 days following TKA. The best fitting model utilized a non-linear time trend, with smoothing splines for median and variance parameters. Additionally, optimization of the number of knots in smoothing splines and power transformation of time improved model fit. The reference chart performed adequately in a test set of 171 patients (377 observations), with accurate centile coverage and minimal average bias (< 3 degrees). CONCLUSION: A reference chart developed with clinically collected data offers a new approach to monitoring knee flexion following TKA.

Movement pattern biofeedback training after total knee arthroplasty: Randomized clinical trial protocol.

INTRODUCTION: Total knee arthroplasty (TKA) reduces joint symptoms, but habitual movement compensations persist years after surgery. Preliminary research on movement training interventions have signaled initial efficacy for remediating movement compensations and restoring knee joint loading symmetry during dynamic functional tasks after TKA. The purpose of this clinical trial is to determine if physical rehabilitation that includes movement training restores healthy movement patterns after TKA and reduces the risk of osteoarthritis (OA) progression in the contralateral knee. METHODS/DESIGN: 150 participants will be enrolled into this randomized controlled trial. Participants will be randomly allocated to one of two dose-equivalent treatment groups: standard rehabilitation plus movement training (MOVE) or standard rehabilitation without movement training (CONTROL). Movement training will promote between-limb symmetry and surgical knee loading during activity-based exercises. Movement training strategies will include real-time biofeedback using in-shoe pressure sensors and verbal, visual, and tactile cues from the physical therapist. The primary outcome will be change in peak knee extension moment in the surgical knee during walking, from before surgery to six months after surgery. Secondary outcomes will include lower extremity movement symmetry during functional tasks, physical function, quadriceps strength, range of motion, satisfaction, adherence, contralateral knee OA progression, and incidence of contralateral TKA. DISCUSSION: This study will provide insights into the efficacy of movement training after unilateral TKA, along with mechanisms for optimizing long-term physical function and minimizing negative sequelae of compensatory movement patterns.

Benefits of direct patient discharge to outpatient physical therapy after total knee arthroplasty.

Purpose: To investigate the effectiveness of home health physical therapy followed by outpatient physical therapy as compared to patients discharged directly to outpatient physical therapy in improving functional performance, strength/activation and residual knee pain outcomes among patients who received a total knee arthroplasty.Materials and methods: A secondary analysis of longitudinal data in which patients with total knee arthroplasty underwent home health physical therapy or were discharged directly to outpatient physical therapy. Main outcome measures included the stair climb test, timed up and go, 6-min walk test, quadriceps and hamstring strength, quadriceps activation and residual knee pain.Results: Patients referred to home health physical therapy prior to outpatient physical therapy demonstrated significantly greater declines in stair climb test (10.3; 95% CI [6.5, 14.1]; t = 5.41; p < 0.0001), timed up and go (2.0; 95% CI [1.0, 3.0]; t = 4.10; p < 0.0001), 6-min walk (53.8; 95% CI [29.4, 78.2]; t = 4.35; p < 0.0001), quadriceps strength (21.7%; 95% CI [19.3%, 24.9%]; t = 2.53; p = 0.01), hamstring strength (44.7%; 95% CI [43.4%, 45.7%], t = 3.17; p = 0.002) and higher residual knee pain (0.53; 95% CI [0.04, 1.03]; t = 2.17; p = 0.03) 1 month after total knee arthroplasty compared to those referred directly to outpatient physical therapy.Conclusions: These findings suggest that patients discharged directly to outpatient physical therapy had a more rapid recovery 1 month after total knee arthroplasty. Additional research is needed to investigate the potential causal relation between care pathways and clinical outcomes following total knee arthroplasty.Implications for rehabilitationTotal knee arthroplasty, typically performed to alleviate end-stage knee osteoarthritis, is the most commonly performed elective surgery in the United States.Despite improvement in pain, objective measurements of functional performance and strength often remain at preoperative levels one year after total knee arthroplasty.Patients discharged directly to higher intensity outpatient physical therapy have a more rapid recovery after total knee arthroplasty compared with those patients who received two weeks of home health prior to undergoing outpatient physical therapy.

Characteristics of young and lower functioning patients following total knee arthroplasty: a retrospective study.

BACKGROUND: Rates of total knee arthroplasty (TKA) procedures in younger, more medically complex patients have dramatically increased over the last several decades. No study has examined categorization of lower and higher functioning subgroups within the TKA patient population. Our study aimed to determine preoperative characteristics of younger patients who are lower functioning following TKA. METHODS: Patients were categorized into higher and lower functioning subgroups defined using a median split of 1) postoperative Timed Up and Go (TUG) test times and 2) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale scores. A split in age (65 years) was used to further classify patients into four categories: younger lower functioning, younger higher functioning, older lower functioning and older higher functioning. Measures from preoperative domains of health, psychological, physical performance and pain severity were examined for between-group differences. RESULTS: Comparing mean values, the younger lower functioning subgroup using the TUG had significantly weaker knee extensor, slower gait speed, higher body mass index and greater pain compared to other subgroups. The younger lower functioning subgroup using the WOMAC physical function subscale demonstrated higher pain levels and Coping Strategies Questionnaire-Catastrophizing Subscale scores compared to the older lower functioning subgroup. CONCLUSIONS: Poorer preoperative physical performance and pain severity appear to have the largest influence on early postoperative TKA recovery in younger lower functioning patients relative to both younger and older higher functioning patients.