Association of Malnutrition With Physical Activity Intensity in Patients With Subacute Stroke.

OBJECTIVE: To investigate the relationship between nutritional status measured by the Global Leadership Initiative on Malnutrition (GLIM) criteria and the intensity of physical activity, and to determine the association between these factors and the activities of daily living (ADLs) in patients with subacute stroke during hospitalization. DESIGN: A cross-sectional study. SETTING: The study was conducted in the rehabilitation unit at a neurosurgical hospital. PARTICIPANTS: One hundred and twenty-eight patients with subacute stroke (N=128). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Nutritional status was assessed using GLIM criteria. Sedentary behavior (SB), light-intensity physical activity (LIPA), and moderate-to-vigorous physical activity (MVPA) were measured using an accelerometer. Multiple regression analysis was used to investigate the relationship between nutritional status and intensity of physical activity. Moreover, the association of nutritional status and physical activity intensity with ADLs was determined using multiple regression analysis and mediation analysis. RESULTS: Malnutrition was associated with SB time (B = 16.241, P=.009) and LIPA time (B = -17.656, P=.002), but not MVPA time (B = -0.472, P=.776). SB time (B = -0.063, P=.009) and LIPA time (B = 0.093, P<.001) were associated with functional independence measure for motor function, while MVPA time (B = -0.080, P=.379) was not. SB time (coefficient = -10.785, P<.001) and LIPA time (coefficient = -12.054, P<.001) were significant mediators between nutrition status and ADLs. CONCLUSIONS: Malnutrition was associated with a SB time and LIPA time, but not MVPA time, in patients with sub-acute stroke. SB and LIPA times were associated with ADLs and mediated between nutrition status and ADLs in these patients. The association of nutritional status on physical activity and ADLs should be considered in stroke rehabilitation.

Association of the Degree of Varus Thrust during Gait Assessed by an Inertial Measurement Unit with Patient-Reported Outcome Measures in Knee Osteoarthritis.

This study aimed to assess the association between the degree of varus thrust (VT) assessed by an inertial measurement unit (IMU) and patient-reported outcome measures (PROMs) in patients with knee osteoarthritis. Seventy patients (mean age: 59.8 ± 8.6 years; women: n = 40) were instructed to walk on a treadmill with an IMU attached to the tibial tuberosity. For the index of VT during walking (VT-index), the swing-speed adjusted root mean square of acceleration in the mediolateral direction was calculated. As the PROMs, the Knee Injury and Osteoarthritis Outcome Score were used. Data on age, sex, body mass index, static alignment, central sensitization, and gait speed were collected as potential confounders. After adjusting for potential confounders, multiple linear regression analysis revealed that the VT-index was significantly associated with the pain score (standardized ß = -0.295; p = 0.026), symptoms score (standardized ß = -0.287; p = 0.026), and activities of the daily living score (standardized ß = -0.256; p = 0.028). Our results indicated that larger VT values during gait are associated with worse PROMs, suggesting that an intervention to reduce VT might be an option for clinicians trying to improve PROMs.

Influence of ultrasound focus depth on the association between echo intensity and intramuscular adipose tissue.

INTRODUCTION/AIMS: Attenuation of the ultrasound (US) wave is a serious limitation of echo intensity (EI) on B-mode US. The aim of this study was to determine whether the focus depth of US images influences the depth-dependent attenuation of EI and the relationship between EI and intramuscular adipose tissues (IntraMAT). METHODS: The rectus femoris (RF) and vastus intermedius (VI) of the right thigh were studied in 135 adults (92 older, 43 younger). The EI on US images was measured at three focus depth conditions: top of the image, center of the RF, and center of the VI. The depth of the region of interest (ROI) was measured. IntraMAT was calculated using water and fat images based on the two-point Dixon technique with a 3.0-T magnetic resonance imaging scanner. RESULTS: The correlation between EI and IntraMAT was stronger in the focus RF and VI conditions than in the focus top condition and stronger for RF than for VI. The depth of the ROI influenced the IntraMAT-adjusted residual EI more in the focus top condition than in the focus RF and VI conditions, and influenced VI more strongly than it did RF. DISCUSSION: By mitigating EI attenuation, EI with a focus depth adjusted to the ROI reflected IntraMAT more accurately than that without adjustment. However, it may not completely prevent the potential influence of depth-dependent attenuation of EI, especially for deeper muscles such as the VI.

The association between fear of falling and occurrence of falls: a one-year cohort study.

BACKGROUND: Both multiple fall experiences and fear of falling (FoF) would make people susceptible to another fall; however, the associations are unknown. This study investigates the association of FoF with fall occurrence among older adults according to their fall history. METHODS: In this study, we adopted a longitudinal observational design. We visited 20 community centers to recruit 1,025 older adults (aged 65 years or older). At baseline, FoF was assessed using a single-item questionnaire. The number of falls in the past year was obtained via a self-questionnaire and participants were classified into three fall history groups (0: non-faller, 1: single faller, 2 or more: multiple faller). After a year of following-up, the number of falls during the year was considered as the main outcome. Poisson regression models clarified the influence of FoF on fall occurrence during the one-year follow-up, according to the participants' fall history. RESULTS: The final sample comprised 530 individuals (follow-up rate: 530/801, 66.4%). Fall history, FoF, and interaction between multiple fallers and FoF were significant in the adjusted statistical model (rate ratio [95% confidence interval]: single faller = 2.81 [1.06, 6.30], multiple faller = 13.60 [8.00, 23.04], FoF = 3.70 [2.48, 5.67], multiple faller*FoF = 0.37 [0.20, 0.68]). CONCLUSIONS: We found that FoF was associated with the occurrence of falls in community-dwelling older adults. However, its association was lower in multiple fallers.

Use of the reliable change index to evaluate the effect of a multicomponent exercise program on physical functions.

AIMS: Using the reliable change index (RCI), we aimed to examine the effect of a multicomponent exercise program on the individual level. METHODS: Overall, 270 adults (mean age, 78 years) completed a multicomponent physical exercise program (strength, aerobic, gait, and balance) for 40 min, 1-2 times per week, continued up to 1 year at a daycare center. Effectiveness was assessed using grip, ankle, knee, and hip strength; Timed Up & Go (TUG); Berg Balance Scale (BBS); gait speed; and 6-min walking distance. These were measured at baseline and every 3 months thereafter. We calculated the RCI using the data between two-time points (baseline and at 3, 6, 9, or 12 months) in each participant and then calculated the mean RCI value across the participants. A paired t-test was also employed to evaluate the effect of the intervention as an average-based statistics. RESULTS: The highest mean RCI values were on ankle plantar-flexion strength, followed by gait speed, hip abduction strength, BBS, knee extensor strength, 6-min walk distance, grip strength, and finally TUG. Paired t-test also revealed significant improvement with moderate effect sizes for ankle plantar-flexion strength (0.504), gait speed (0.413), hip abduction strength (0.374), BBS (0.334), knee extensor strength (0.264), and 6-min walk distance (0.248). Significant but small effect size was seen on TUG (0.183). CONCLUSION: The RCI is a convenient method of comparing the effect between different assessments, especially at an individual level. This index can be applied to the use of personal feedback.

Applied Assessment Method for Varus Thrust during Walking in Patients with Knee Osteoarthritis Using Acceleration Data Measured by an Inertial Measurement Unit.

We developed a novel quantitative method to assess varus thrust during walking using acceleration data obtained from an inertial measurement unit (IMU). This study aimed to examine the reliability of the developed index and to evaluate its ability to distinguish patients with knee osteoarthritis (OA) with varus thrust from healthy adults. Overall, 16 patients with knee OA and 16 healthy adults walked on a treadmill with IMUs attached to the tibial tuberosity and lateral femoral condyle. As an index of varus thrust, we used the root mean square (RMS) of acceleration in the mediolateral direction. This value was adjusted by dividing it by swing speed while walking (adjusted RMS, A-RMS) because the RMS of the acceleration was strongly coupled with the speed of motion. The intraclass correlation coefficients of A-RMS of the tibia and femur were 0.85 and 0.73, respectively. Significant differences were observed in the A-RMSs of the tibia and femur, with large effect sizes between the patients with knee OA and healthy adults (Cohen's d: 1.23 and 0.97, respectively). Our results indicate that A-RMS has good test-retest reproducibility and can differentiate patients with varus thrust from healthy adults.

Development and persistence of fear of falling relate to a different mobility functions in community-dwelling older adults: one-year longitudinal predictive validity study.

BACKGROUND: Fear of falling (FoF) is a common psychological problem in community-dwelling older adults. However, which mobility function relate to newly developed FoF and persistent FoF are unknown. AIMS: We aimed to clarify which baseline mobility function is an independent predictor of one-year change in FoF. METHODS: The study design was a one-year longitudinal predictive validity study. Participants were 581 independently community-dwelling older adults without neurological disorders. We measured FoF, history of falls, inactive lifestyle, and sociodemographic data were obtained via a self-administered questionnaire. Mobility functions were measured by community-based Short Physical Performance Battery (SPPB-com). RESULTS: Newly developed FoF group accounted for 20% among the non-FoF older adults at baseline. Persistent FoF group accounted for 57% among the older adults with FoF at baseline. Risk of newly developed FoF was significantly related to the SPPB-com total score, among the mobility functions, the low gait test score (OR [95% CI] = 2.34 [1.12-5.12]) and the low tandem balance test score (OR [95% CI] = 3.62 [1.46-8.90]) were significantly related. Risk of persistent FoF was also related to SPPB-com total score, among the mobility functions, the five chair stand test score (OR [95% CI] = 1.96 [1.19-3.24]) was significantly related. DISCUSSION AND CONCLUSION: The risk of newly developed FoF related to lower ability of standing-balance and gait, the risk of persistent FoF related to lower sit-to-stand ability. Appropriate exercise interventions according to FoF subtype may effectively prevent the risk of developing FoF or experiencing persistent FoF.

Does dual-tasking provide additional value in timed "up and go" test for predicting the occurrence of falls? A longitudinal observation study by age group (young-older or old-older adults).

BACKGROUND: Previous studies using relatively large samples and longitudinal observational designs reported dual-tasking had additional value in timed "up and go" test (TUG) for falls assessment among well-functioning older adults. AIM: To elucidate the additional value of dual-tasking in TUG for predicting the occurrence of falls among community-dwelling older adults by age group using a predictive model. METHODS: This longitudinal observation study included 987 community-dwelling older adults at baseline. A TUG without performing another task (single-TUG) and a TUG while counting aloud backward from 100 were conducted at baseline. We computed the dual-task cost (DTC) value, which is used to quantify trends in subjects' execution of motor tests under dual-task conditions. Data on fall history were obtained using a self-administered questionnaire at the 1-year follow-up. The final analysis included 649 individuals divided into a young-older adult group (aged 60-74 years) and an old-older adult group (aged ≥ 75 years). Associations between the occurrence of falls and TUG-related values were analyzed by age group using multivariate logistic regression models. RESULTS: For old-older adults, there were significant associations between the occurrence of falls and single-TUG time (odds ratio [OR] 1.143, 95% confidence interval [CI] 1.018-1.285) and DTC value (OR 0.981, 95% CI 0.963-0.999). No significant associations were observed for young-older adults. CONCLUSIONS: Slower single-TUG time and lower DTC value are associated with the occurrence of falls among old-older adults but not among young-older adults. Dual tasking may provide an additional value in TUG for predicting falls among old-older adults.

Concurrent validity of the step time and walking speed obtained from the smartphone application CareCoaching in independent, community-dwelling older adults.

[Purpose] In this study, we verified the validity of the step time and walking speed obtained from the smartphone gait analysis application CareCoaching. [Participants and Methods] The participants were 66 independent, community-dwelling adults aged 65 years or older who performed a 10-m walking test twice each under preferred- and slow-speed conditions. We concurrently measured gait motions using CareCoaching and the OptoGait system for reference data. Both systems compute walking speed and step time as gait parameters. We examined the concurrent validity of these parameters by using intra-class correlation coefficients (ICCs) and limits of agreement (LOAs) with Bland-Altman analyses. [Results] In the preferred walking speed condition, the ICCs of walking speed and step times between the CareCoaching and the OptoGait system were 0.67 and 0.93, respectively. In the slow walking speed condition, the ICCs for walking speed and step time were 0.78 and 0.97, respectively. In addition, the LOAs for step time were -0.0941 to 0.1160 for preferred walking speed and -0.0596 to 0.0883 for slow walking speed. The LOAs for walking speed were -0.4158 to 0.0568 for preferred walking speed and -0.3348 to 0.0523 for slow walking speed. [Conclusion] CareCoaching showed excellent agreement for step time and moderate-to-good agreement for walking speed in independent, community-dwelling older adults.

Is increased "stay away from bed" time associated with improved clinical rehabilitation outcomes in Japanese rehabilitation hospitals? A prospective observational study and clinical practice.

BACKGROUND: A comprehensive team approach for increasing stay away from bed time (SaB-time) called CASaB was conducted at multiple rehabilitation hospitals. AIMS: The aim of the present study was to investigate the association between SaB-time and clinical rehabilitation outcomes (CROs) before introducing CASaB (observational phase), and comparing CROs before and after CASaB (CASaB phase). METHODS: This prospective observational study included patients who were admitted to nine rehabilitation hospitals, with complete data. The final analysis included 197/229 patients in the observation phase, and 229/256 patients in the CASaB phase. We first tested whether SaB-time was positively associated with CROs in an observational study, then compared CROs before and after CASaB. RESULTS: In the observation phase, longer SaB-time was significantly associated with greater rehabilitation efficiency (REy) after adjusting for confounders (standardized ß = 0.20, p = 0.007). In a comparison of CROs before and after CASaB, the length of hospital stay during the CASaB phase was significantly shorter than during the observational phase (61.5, 57.6-65.4 days vs 75.6, 71.4-79.9 days, p < 0.001), and the REy after CASaB was significantly greater than that before the CASaB (0.38, 0.33-0.42/day vs 0.28, 0.25-0.33/day, p = 0.006). DISCUSSION: The current results suggest that increasing SaB-time may help the recovery of functional abilities, particularly for patients in rehabilitation hospitals. CONCLUSIONS: The CASaB provides a method for improving the recovery efficiency of patients in rehabilitation hospitals.

Association of fear of falling with acceleration-derived gait indices in older adults with knee osteoarthritis.

BACKGROUND: Knee osteoarthritis (OA) and fear of falling (FoF) are important factors contributing to trunk oscillation during walking. It is of a clinical importance to clarify the association of FoF with trunk oscillation during walking in older adults with knee OA (knee OA adults). AIM: The purpose of this study was to investigate the association of FoF with trunk oscillation during walking in knee OA adults. METHODS: Forty-one patients who met the criteria participated in the study and were classified into two groups based on their answer to a question on FoF. An accelerometer was attached at the level of the third lumbar vertebra (L3) and the seventh cervical vertebra (C7), and the accelerations at L3 and C7 were measured during a 10-m gait test. Using these data, the acceleration-derived gait indices, such as stride time variability (STV), root mean square (RMS), and autocorrelation at the trunk in the anteroposterior (AP) and mediolateral (ML) directions, were computed. RESULTS: FoF was associated with a higher STV value and a smaller RMS value in the ML direction at L3. DISCUSSION: The decreased trunk oscillation in the ML direction in knee OA adults with FoF may reflect a positive, compensatory adaptation for trunk control. CONCLUSION: Knee OA adults with FoF decreased trunk oscillation during walking than those without FoF.

Development and validation of Comprehensive Gait Assessment using InerTial Sensor score (C-GAITS score) derived from acceleration and angular velocity data at heel and lower trunk among community-dwelling older adults.

BACKGROUND: Although some gait parameters from inertial sensors have been shown to be associated with important clinical issues, because of controversial results, it remains uncertain which parameters for which axes are clinically valuable. Following the idea that a comprehensive score obtained by summing various gait parameters would sensitively reflect declines in gait performance, we developed a scoring method for community-dwelling older adults, the Comprehensive Gait Assessment using InerTial Sensor score (C-GAITS score). The aim of this study was to examine the internal consistency and the construct validity of this method. METHODS: In this cross-sectional study, the gait performance of 378 community-dwelling older people (mean age = 71.7 ± 4.2 years, 210 women) was assessed using inertial sensors attached to the heel and lower trunk. Participants walked along a 15-m walkway, and accelerations, angular velocity, and walking time were measured. From these data, walking speed, mean stride time, coefficients of variation of stride time and swing time, and autocorrelation coefficients and harmonic ratios of acceleration in vertical, mediolateral, and anteroposterior directions at the lower trunk were calculated. Scoring was performed based on quartile by gender (i.e., scored from 0 to 3) for each of the 10 gait parameters. The C-GAITS score was the sum of these scores (range: 0-30). Lower extremity strength, balance function, fall history, and fear of falling were also assessed. RESULTS: An exploratory factor analysis revealed that the C-GAITS score yielded four distinct factors explaining 57.1% of the variance. The Cronbach's alpha coefficient was 0.77. A single linear regression analysis showed a significant relationship between total C-GAITS score and walking speed (adjusted R2 = 0.28). Results from bivariate comparisons using unpaired t-tests showed that the score was significantly related to age (p = 0.002), lower extremity strength (p = 0.007), balance function (p <  0.001), fall history (p = 0.04), and fear of falling (p <  0.001). CONCLUSIONS: Good internal consistency and appropriate construct validity of the C-GAITS score were confirmed among community-dwelling older adults. The score might be useful in clinical settings because of ease of use and interpretation and capability of capturing functional decline.

Associations of the step-up test and lower limb dysfunction: A post-hoc analysis of a prospective cohort study.

BACKGROUND: Step-up ability is considered to be associated with lower limb dysfunction. The objective of this research was to assess the height of the tallest step that could be mounted and to investigate its association with lower limb dysfunction. METHODS: We previously conducted a two-year follow-up prospective cohort study. The study subjects were 119 patients receiving physiotherapy or exercise therapy at an orthopedic surgery clinic. The items evaluated were step-up ability (maximum step height), the timed up and go test, one-leg standing time and the 5-question Geriatric Locomotive Function Scale. The primary endpoint was the prevalence of locomotive syndrome, whereas secondary endpoint was musculoskeletal ambulation disability symptom complex (MADS). Evaluations were carried out at the time of the initial assessment and two years later. We used a multiple logistic regression model with age, sex, height, weight and each functional test as exploratory variables. R2 and C-statistics were calculated and these "optimism" biases were corrected using a bootstrap technique. RESULTS: Maximum step height was strongly correlated with the prevalence of locomotive syndrome [odd ratio (95% confidence intervals), 0.52 (0.32, 0.87), p = 0.0074] and was correlated with MADS [0.45 (0.22, 0.92), p = 0.0138]. Additionally, maximum step height was also strongly correlated with post follow-up locomotive syndrome [0.39 (0.18, 0.84), p = 0.0010]. CONCLUSION: The results suggest that step-up ability may represent a simple and useful tool which is associated with lower limb dysfunction.

The association between fear of falling and smoothness of lower trunk oscillation in gait varies according to gait speed in community-dwelling older adults.

BACKGROUND: Fear of falling (FoF) is common in community-dwelling older adults. FoF and increased walking speed are associated with lower trunk oscillation during gait in older adults. We hypothesized that older adults with FoF would struggle to walk safely when instructed to walk faster than usual. METHODS: Participants included 260 community-dwelling older adults aged over 65 years (mean age = 71.9 ± 3.9 years) who were able to walk independently without an assistive device. Participants were instructed to walk along a 15-m smooth horizontal walkway at self-selected normal and fast gait speeds. During the middle 10 m of the walk, oscillation of the lower trunk and stride times were measured with two accelerometers. We examined associations between gait variables, including harmonic ratio (HR) in vertical, mediolateral (HR-ML) and anteroposterior (HR-AP) directions as indicators of smoothness of lower trunk oscillation, as well as stride time variability (STV) and FoF. RESULTS: Gait-speed- and STV- adjusted models showed that FoF was significantly associated with HR-ML in the normal-gait condition (HR-ML: ß = - .135, p = .040), while FoF was significantly associated with HR-AP in the fast-gait condition (HR-AP: ß = - .154, p = .017). CONCLUSIONS: FoF-related changes in gait vary with gait speed. In older adults with FoF, lower trunk oscillation was less smooth in the lateral direction when they walked at their usual pace. In addition, lower trunk oscillation was also less smooth in the direction of travel when they walked at a faster pace than their usual walking speed.

Multi-chronic musculoskeletal pain is a useful clinical index to predict the risk of falls in older adults with normal motor function.

BACKGROUND: The number of chronic musculoskeletal pain sites (nCMSP) is reportedly associated with risk of falls. Older participants in community-based research show a wide range of physical functions, but few studies have focused on the risk of falls in older adults with normal motor function (NMF). Clarification of the effects of pain on dual-tasking performance is also important, given the strong link between falls and dual-tasking. AIMS: The objectives were to investigate the associations between: (1) nCMSP and falls; and (2) nCMSP and dual-task performance in older adults with NMF. METHODS: A total of 112 older adults with NMF (44 men, 68 women; 73.4 ± 4.6 years) were classified as fallers (n = 22) or non-fallers (n = 90) according to their fall history. Musculoskeletal pain in the lower body was assessed using questions ascertaining pain in musculoskeletal sites (back, hip, knee, foot, or toe). Participants were assigned to three pain groups according to nCMSP. Basic physical performances and gait performances (normal gait, fast gait, or dual-task gait) were measured. RESULTS: The nCMSP represented a significant risk factor for falls according to logistic regression modeling after adjusting for the five chair stand test and fear of falls. The nCMSP was not associated with any gait variables. DISCUSSION: Potential fall risk may be increased by nCMSP, even in older adults with NMF. Pain-related reduction in attention resources may not represent a risk factor for falls among older adults with NMF. CONCLUSIONS: The nCMSP represents a potential risk factor for falls in older adults with NMF.

Association between toe flexor strength and spatiotemporal gait parameters in community-dwelling older people.

BACKGROUND: The toe flexor muscles perform a crucial function to control foot movement and assist with propulsive force when walking. However, the association between toe flexor strength and spatio-temporal gait parameters is largely unknown. Spatiotemporal gait parameters represent gait characteristics, and are good measures of the functional status and degree of safe ambulation among community-dwelling older adults. Herein, we examined the association between the toe flexor strength and spatiotemporal gait parameters in community-dwelling older adults. METHODS: Ninety-three community-dwelling older people (mean age: 73.2 ± 4.2 years, 53 women) participated in this study. The strength of the toe flexor muscles was assessed using a toe strength measuring instrument and a strain gauge. The measurements were performed once on each foot, and the average of the right and left was used in the analysis. Gait analysis was performed on a 15-m walkway under usual- and fast-pace conditions. The medial 10-m walking time was measured and walking speed was calculated. Acceleration and angular velocity of the right heel were measured using a wireless miniature sensor unit and used to compute cadence, percent of swing time in gait cycle (%swing time), and stride length. RESULTS: In multiple regression analyses adjusted for age, sex, body height, body weight, and hand grip strength, no associations between toe flexor strength and spatiotemporal gait parameters at usual pace were found. Conversely, under the fast-pace condition, decreased toe flexor strength was significantly associated with slower walking speed (ß = 0.22, p = 0.049), lower%swing time (ß = 0.34, p = 0.009), and shorter stride length (ß = 0.22, p = 0.011) after adjustment. CONCLUSION: In community-dwelling older people, decreased strength of toe flexor was correlated with slower walking speed, shorter periods of single-limb support phase, and shorter stride length during fast-pace walking. These data provide further support for an important role of toe flexor muscles in walking.

Usefulness of gait parameters obtained from inertial sensors attached to the lower trunk and foot for assessment of gait performance in the early postoperative period after total knee arthroplasty.

BACKGROUND: This study was performed to (i) compare gait parameters obtained from inertial sensors attached to the lower trunk and foot between patients in the early postoperative period after total knee arthroplasty (TKA) and healthy age- and sex-matched controls and (ii) elucidate the association between the gait parameters and patient-reported outcome measures (PROMs). METHOD: The gait performance of 19 patients who had undergone TKA was assessed using inertial sensors and PROMs obtained from the Knee Injury and Osteoarthritis Outcome Score (KOOS) 1 week before hospital discharge. The patients walked along a 15-m walkway and we calculated the following gait parameters: walking speed, coefficient of variation (CV) of stride time, unbiased autocorrelation coefficient (AC), harmonic ratio (HR), and symmetry index (SI). The same gait parameter data from 19 age- and sex-matched healthy adults (controls) were obtained from our past study. RESULTS: The TKA group demonstrated slower walking speed, larger CV of stride time, lower HR in all three directions, lower AC in the vertical direction, and higher SI in the vertical direction than the healthy control group (all p < 0.05). Correlation analysis revealed that the SI in the anteroposterior direction was significantly correlated with the KOOS symptoms subscore and ADL subscore (p < 0.05). CONCLUSIONS: Patients in the early postoperative period after TKA exhibited worse gait performance as assessed by inertial sensors compared with healthy controls. Gait symmetry was correlated with PROMs. These results indicate the usefulness of assessing gait parameters after TKA.

Association between knee extensor force steadiness and postural stability against mechanical perturbation in patients with Parkinson's disease.

OBJECTIVE: Lower extremity force steadiness has been shown to decrease with aging and neuromotor dysfunction and to be associated with physical function and fall. Although patients with Parkinson's disease (PD) experience decreased force steadiness, whether the extent of force steadiness differs according to target force or whether this steadiness is associated with postural control remain unclear. Therefore, this study aimed to compare the force steadiness while steadily exerting low and moderate levels of knee extensor force between individuals with and without PD and to examine the association between force steadiness and postural instability against mechanical perturbation in PD. METHODS: A total of 33 patients with PD (mean age, 71.7 years) and 33 healthy controls (72.2 years) participated in this study. Participants with PD were classified into postural stability or instability groups based on the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale motor exam item 12. Participants performed steady task of the knee isometric extension at two levels (10% and 50% of maximal voluntary contraction [MVC]). RESULTS: Force steadiness at 10% MVC was lower in postural instability group than that in the control and postural stability groups (P < 0.05) after adjusting for age, sex, and body mass index, whereas it was not significantly different at 50% MVC among the three groups. DISCUSSION: These results suggest that the knee extensor force steadiness is affected in patients with PD having postural instability against mechanical perturbation during low intensity force exertion and is not affected regardless of the presence of postural instability during moderate intensity force exertion.

Changes in Muscle Thickness and Echo Intensity in Chronic Stroke Survivors: A 2-Year Longitudinal Study.

BACKGROUND AND PURPOSE: The objective of this study was to identify 2-year longitudinal changes in the muscle thickness (MT) and echo intensity (EI) of the abdominal, thigh, and lower limb muscles in chronic stroke survivors. METHODS: This study included 15 chronic stroke survivors aged 74.1±9.9 years. The MT, EI, and subcutaneous fat thickness values of the following muscles on the paretic and nonparetic sides were assessed on transverse ultrasound images: rectus abdominis, external oblique, internal oblique, transversus abdominis, rectus femoris (RF), vastus intermedius, vastus lateralis (VL), vastus medialis, tibialis anterior, gastrocnemius, and soleus. The ultrasound measurements were performed both at baseline and 2 years later. RESULTS: After 2 years, the VL on the paretic side showed a significant decrease in MT (p=0.031) and increase in EI (p=0.002), whereas the RF on the nonparetic side showed a significant decrease in EI (p=0.046). Correlation coefficient analyses showed that changes in MT (r=0.668, p=0.012) and EI (r=0.597, p=0.018) of the VL on the paretic side were significantly associated with a change in the body mass index. CONCLUSIONS: The findings of this longitudinal study suggest that the VL on the paretic side is subject to deteriorations in muscle quantity and quality, and conversely that the RF on the nonparetic side shows an improvement in muscle quality after 2 years in chronic stroke survivors.

Value of the 3-min walk test and its association with motor functions in older adults.

BACKGROUND: The 3-min walk test (3MWT) has been used in the clinical setting. OBJECTIVE: To present the 3MWT value and investigate its association with motor and respiratory functions of healthy older adults. METHODS: Two hundred six older adults and 27 younger adults were enrolled. The 3MWT was assessed by the walking distance within 3 min. Knee extension muscle strength (KEMS), 5-repetition sit-to-stand (5 R-STS), Timed Up and Go (TUG), forced vital capacity (FVC), forced expiratory volume 1.0 (FEV1.0), maximal expiratory pressure (MEP), and maximal inspiratory pressure (MIP) were measured. The 3MWT distance was examined by age group (18-39, 60-69, 70-79, and 80-89 years). A multivariate regression analysis investigated the association between 3MWT and motor function test. RESULTS: The 3MWT values in each age group were 273-385, 233-414, 93-351, and 171-345 m for men and 215-375, 220-349, 198-325, and 174-332 m for women respectively. The 3MWT values were correlated with age, body mass index (BMI), KEMS, 5 R-STS, TUG, FVC, FEV1.0, MEP, and MIP. On the multivariate regression analysis, 3MWT was significantly associated with BMI (standard beta = -0.18; 95% confidence interval [CI], -3.20 to 0.83), KEMS (standard beta = 0.37; 95% CI, 0.06-0.13), 5 R-STS (standard beta = -0.13; 95% CI, -5.70 to -0.13), and TUG (standard beta = -0.36; 95% CI, -17.15 to -7.73) in older adults (adjusted R2 = 0.47). CONCLUSIONS: The 3MWT distance decreased with age and was associated with motor and respiratory functions. No range trends were observed among groups. Our findings suggest that 3MWT reflects functional capacity.