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.

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.

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.

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.

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.

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.

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.

Association between Abnormal Gait Patterns and an Elevated Degree of Pain after Daily Walking: A Preliminary Study.

This study aimed to investigate whether abnormal gait patterns are associated with experiencing an elevated degree of pain after daily walking. In this preliminary, cross-sectional study, 223 community-dwelling older adults were assessed for pain experienced after daily walking using a simple question that involved asking the subject about their past experiences of an elevated degree of pain after walking for 400 m or more. Gait patterns were assessed using the Comprehensive Gait Assessment using InerTial Sensor score (C-GAITS score), derived from the data measured by Inertial sensors attached to the lower trunk and heel when subjects walked along a 15 m walkway at a self-selected preferred speed. The score was the sum of 10 gait parameter scores. The lower scores indicated more and worse abnormal gait patterns. In total, 24 older adults (10.8%) reported that they experienced pain after daily walking. According to the multiple logistic regression analyses, older adults with a lower total C-GAITS score had a significantly greater probability of having past experiences of pain after walking (odds ratio = 1.11, 95% confidence interval = 1.03-1.20). The findings of this study suggest that more and worse abnormal gait patterns among older adults in a clinical walking test are associated with an elevated degree of pain after daily walking.

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.

Longitudinal effects of physical exercise on health-related outcomes based on frailty status in community-dwelling older adults.

AIM: To clarify the difference in the longitudinal effects of physical exercise on health-related outcomes according to the baseline frailty status (frail or non-frail) in community-dwelling older adults. METHODS: Participants included 177 adults aged ≥65 years who carried out multicomponent physical exercises (strength, aerobic, gait and balance) for 40 min, one to three times per week, for 1 year at a day-care center. Bodyweight, comfortable walking speed, 6-min walking distance and Mini-Mental State Examination were measured at baseline and every 3 months. For longitudinal trend, we analyzed the change in scores from baseline for each outcome using the linear mixed effects model. Fixed effects included "group" (frail or non-frail), "time" (4 time points every 3 months, from 3 to 12 months) and "interaction between group and time." RESULTS: The effect sizes from baseline showed almost all positive values for each outcome. The linear mixed effects model showed significant effects on "interaction between group and time" in changes in bodyweight (P = 0.033), "group" in changes in walking speed (P = 0.013) and "time" in changes in the Mini-Mental State Examination (P < 0.001). Bodyweight showed a decreasing trend in the non-frail group after 3 months, unlike in the frail group. For walking speed, moderate effect sizes (d = 0.67-0.74) were sustained over time in the frail group, as did lesser effect sizes (d = 0.26-0.40) in the non-frail group. CONCLUSIONS: Exercise-based multicomponent interventions were effective for both groups. The longitudinal effects on walking speed and bodyweight were greater in the frail group. Geriatr Gerontol Int 2022; 22: 213-218.

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.

Cut-off Values for Lower Limb Muscle Thickness to Detect Low Muscle Mass for Sarcopenia in Older Adults.

PURPOSE: Ultrasound-based prediction methods for the detection of low muscle mass for sarcopenia in older adults have been explored previously; however, the muscle that most accurately predicts it is unclear. This study aimed to clarify prediction accuracy and cut-off values for ultrasound-derived thigh and lower leg muscle thickness (MT) to detect low skeletal muscle mass index (SMI) in older adults and to estimate cut-off values based on two standard deviations (SD) below younger adult means for the corresponding muscles as an early detection tool for site-specific low muscle mass. METHODS: This study included 204 community-dwelling older (64 males, 140 females, mean age: 75.4 years) and 59 younger (31 males, 28 females, mean age: 22.3 years) adults. The MT of the rectus femoris, vastus intermedius, gastrocnemius, and soleus muscles was measured using ultrasound; SMI was measured using bioelectrical impedance analysis. RESULTS: The prevalence of a low SMI among older adults was 20.3% (n=13) for males and 21.4% (n=30) for females. The receiver operating characteristic analysis revealed that the total MT for the four muscles measured presented the highest area under the curve (AUC) value to predict low SMI for males (0.849) and females (0.776). The AUC value was the highest for the total MT of the gastrocnemius and soleus muscles for males and the gastrocnemius for females (0.836, 0.748; cut-off value: 5.67 cm, 1.42 cm, respectively). Muscle-specific differences between the low SMI-predicting and SD-based cut-off values were observed. The SD-based value for the rectus femoris (1.85 cm) was substantially higher than the low SMI-predicting value (1.51 cm) in males. CONCLUSION: Ultrasound measurement of lower leg muscles may be a simple, robust measure to detect low muscle mass for sarcopenia. Additionally, cut-off values for site-specific muscle mass loss may not always agree with those for whole-limb muscle mass loss.

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.

A Cross-Sectional Study on the Association between Body Mass Index and Frailty According to Sex in Elderly Patients with Disabilities from an Elderly Day-Care Center.

The association between body mass index (BMI) and frailty in elderly patients with disabilities is unclear. We aimed to investigate the association between BMI and frailty in the elderly with disabilities according to sex. This cross-sectional study included 280 elderly patients with disabilities from an elderly daycare center. BMI classification for the Asian population was used to categorize the patients into four groups: underweight, normal, overweight, and obese. Frailty score was based on the phenotypic definition of frailty and consisted of five criteria derived from the revised Japanese version of the Cardiovascular Health Study. Those who had three or more criteria were considered frail. Logistic regression models were constructed to investigate the associations between frailty and BMI in each group (males and females). In females, being underweight was significantly associated with frailty after adjusting for confounders (age and Mini-Mental State Examination score); after adding medical history as a confounder, the aforementioned association was not significant. In males, BMI was not significantly associated with frailty. The association between BMI and frailty differed according to sex among the elderly with disabilities. This finding provides important information regarding frailty risk to workers in daycare facilities.

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.

Comparison of voluntary cough function in community - dwelling elderly and its association with physical fitness.

OBJECTIVE: To compare the association of cough peak flow (CPF) with aging in community-dwelling older adults and to investigate the relationship between physical fitness and CPF in these individuals. METHOD: Two hundred twenty two community-dwelling older adults were enrolled. CPF was assessed as a cough function parameter. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1.0) were assessed as respiratory function. Maximal expiratory pressure (MEP) and inspiratory pressure (MIP) were assessed as respiratory muscle strength. The 3-minute walk test (3MWT) performance was assessed as a physical fitness. Participants were divided into the following age groups: 60-64, 65-69, 70-74, 75-79 and 80-89 years. One way analysis of variance were computed for comparison between age group, sex and CPF. Multivariate regression analyses were used to investigate the association of CPF with 3MWT. RESULTS: The value of CPF significantly decreased in the 75-79 and 80-89 years group than 60-64 years group in men and in the 80-89 years group than 65-69 years group in women. The value of CPF were 545.5, 497.2, 403.3, 354.8 and 325.4 L/min in the 60-64, 65-69, 70-74, 75-79 and 80-89-year group in men and 263.4, 278.8, 264.5, 214.0, and 193.6 L/min in the corresponding age groups in women, respectively. 3MWT (p = 0.041) was significantly associated with CPF. CONCLUSIONS: Cough function tends to decrease with aging in community-dwelling elderly. Physical fitness is associated with cough function.

Effect of improvement in quadriceps strength asymmetry on trunk movement asymmetry after total knee arthroplasty.

BACKGROUND: Patients with knee osteoarthritis (OA) demonstrate trunk movement asymmetry during walking; this asymmetry is associated with disability and quadriceps strength asymmetry. RESEARCH QUESTION: What are the differences between trunk movement asymmetries before and after total knee arthroplasty (TKA) and associations between the changes in trunk movement asymmetry and quadriceps strength asymmetry? METHODS: In this prospective cohort study, 27 patients (mean age, 71.0 years; women, 85.2%) were assessed at 1 month before and 6 months after surgery. Trunk movement asymmetry (harmonic ratio) was assessed at their preferred pace using a triaxial accelerometer. The isometric quadriceps strength was evaluated using a hand-held dynamometer, and the quadriceps strength inter-limb absolute difference was calculated. Multivariate analyses were performed to compare the trunk movement asymmetries before and after surgery with covariate adjustment (gait pain, gait velocity, and non-operated-limb Kellgren and Lawrence [K&L] grade) and to investigate the association between the changes in trunk movement asymmetry and quadriceps strength inter-limb difference with covariate adjustment (age, sex, and non-operated-limb K&L grade). RESULTS: The trunk movement asymmetry in the medio-lateral (mean difference, 0.61; 95% confidence interval [CI], 0.22 to 1.00) and antero-posterior (mean difference, 1.15; 95% CI, 0.48 to 1.83) directions significantly decreased postoperatively compared with the preoperative results. A decreased quadriceps strength inter-limb difference was significantly associated with a decreased medio-lateral trunk movement asymmetry (ß = 0.68; 95% CI, 0.30 to 1.06). SIGNIFICANCE: TKA plays an important role in the improvement of trunk stability during walking in patients with knee OA. Decreasing quadriceps strength asymmetry may be a key to improving trunk movement asymmetry.

Navicular drop is negatively associated with flexor hallucis brevis thickness in community-dwelling older adults.

BACKGROUND: Flatfoot is characterized as a lower longitudinal arch and is a common foot deformity in older adults. Foot intrinsic muscle dysfunction has been considered as one of the factors for a lower medial longitudinal arch. The objective of this study was to investigate the association of the navicular drop with the thickness of foot intrinsic muscles in older adults. RESEARCH QUESTION: Which intrinsic muscle contributes most to support the medial longitudinal arch in older adults? METHODS: We studied 88 community-dwelling older adults (mean age 74.2 ± 6.2 years). We measured the navicular height, the calcaneus inclination, and hallux valgus angle on the right foot in the sitting and standing positions using a 3D foot scanner. Then, we calculated the navicular drop and changes in the calcaneus inclination from the sitting to the standing position. The muscle thickness of the flexor hallucis brevis (FHB), flexor digitorum brevis (FDB), and abductor hallucis (AbH) was measured on the right foot using Bmode ultrasonography. RESULTS: Multiple regression analysis demonstrated that FHB thickness was significantly associated with navicular height in the standing positions (ß = 8.568, P = 0.016) as well as navicular drop (ß = -9.495, P = 0.037) after adjusting for age, sex, height, weight, and hallux valgus angle. There was no association with FDB or AbH. The thickness of any intrinsic muscle was not associated with the calcaneus inclination or changes in the calcaneus inclination. SIGNIFICANCE: Our data suggest that FHB plays an important role in preventing navicular drop and that intrinsic muscles likely do not contribute to the rearfoot angle in older adults.