Differential association of total and regional muscle mass and quality with physical performance in community-dwelling older adults.

PURPOSE: In this study, we examined the association among total muscle mass, regional muscle mass, muscle quality, and various types of physical performance in community-dwelling older adults. METHODS: This study included 195 community-dwelling older adults (61 males and 134 females). The muscle thickness and echo intensity of the quadriceps femoris and triceps surae were measured using ultrasound, and the skeletal muscle mass index was evaluated using bioelectrical impedance analysis. Physical performance was measured using the 30-s standing test (CS30), Timed up-and-go test (TUG), 10-m maximum walking speed (10MWT), vertical jump test (VJT), and grip strength. RESULTS: Partial correlation analysis after controlling for age, sex, and body mass index showed that CS30 was significantly correlated with muscle thickness and echo intensity of the quadriceps femoris. The TUG and VJT were significantly correlated with muscle thickness of the triceps surae, and grip strength was significantly correlated with muscle thickness of the triceps surae and skeletal muscle mass index. Stepwise multiple regression analyses indicated that the echo intensity of the quadriceps femoris was a significant predictor of CS30, and the muscle thickness of the triceps surae was a significant predictor of TUG, VJT, and grip strength, whereas the skeletal muscle mass index was not a significant predictor of any physical performance test. CONCLUSION: Our results suggest that regional muscle mass and quality are more important than skeletal muscle mass index for predicting physical performance.

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.

Differences in muscle thickness and echo intensity between stroke survivors and age- and sex-matched healthy older adults.

OBJECTIVE: The stroke survivors exhibit change in muscle quantity and quality compared to healthy older adults. This study aimed to compare the muscle thickness (MT) and echo intensity (EI) values of individual muscles between stroke survivors and age- and sex-matched healthy older adults. METHODS: In total, 27 stroke survivors and 34 healthy older adults participated in this study. The MT and EI values of the following muscles were assessed from transverse ultrasound images: rectus abdominis (RA), external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius (VI), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), gastrocnemius (Gas), and soleus (Sol). The MT and EI values of these muscles were compared between stroke survivors and healthy older adults. RESULTS: The MT values of the VL, VM, and RA on the non-paretic sides were significantly higher and those of the TA, Gas, and Sol on the paretic sides were significantly lower in the stroke survivors than in the healthy older adults (P < 0.05). The EI values of the VI, VL, VM, TA on the paretic sides and those of the Gas on both the paretic and non-paretic sides were significantly higher in the stroke survivors than in the healthy older adults (P < 0.05). CONCLUSION: Stroke survivors seem to develop muscle hypertrophy of the non-paretic thigh muscles owing to a compensatory strategy. In addition, the lower-leg muscles on the paretic side of stroke survivors tend to show both quantitative and qualitative muscle changes.

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.

Muscle Thickness and Echo Intensity of the Abdominal and Lower Extremity Muscles in Stroke Survivors.

BACKGROUND AND PURPOSE: This study compared the muscle thickness (MT) and echo intensity (EI) of the abdominal, thigh, and lower leg muscles between the paretic and nonparetic sides in chronic stroke survivors. METHODS: Thirty-two stroke survivors living in the community participated in this study. The MT and EI, which are indicators of muscle mass and intramuscular fat or connective tissue, were assessed in the rectus abdominis, external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, tibialis anterior, gastrocnemius, and soleus via transverse ultrasound imaging. In addition, a possible indicator of physical activity-the frequency of going out per week-was evaluated. RESULTS: All quadriceps muscles and the tibialis anterior were significantly thinner and the EI values of the vastus intermedius, vastus lateralis, vastus medialis, and soleus were significantly higher in the paretic limb than the nonparetic limb. The MT and EI values of abdominal muscles did not differ significantly between the two sides. The MT values of the paretic rectus femoris, vastus lateralis, and vastus medialis were significantly associated with the frequency of going out after adjusting confounding factors. The MT of the nonparetic vastus lateralis was significantly associated with latency from stroke onset after adjusting confounding factors. CONCLUSIONS: Our results indicate that quantitative and qualitative changes on the paretic side in stroke survivors were the most robust in the thigh muscles, whereas such changes might not occur in the abdominal muscles.