ECSS Paris 2023: OP-MH25
INTRODUCTION: Gait performance is a critical indicator of physical function and activity of daily living in later life. Extensive research has established that gait parameters are strongly associated with falls, all-cause mortality and other adverse health outcomes. However, the relationship between balance and gait, particularly the dose-response relationship, remains unclear in middle-aged and older adults. Therefore, this study aims to investigate the association between static balance ability and spatio-temporal gait parameters during single-task and dual-task conditions among Chinese adults aged 40 to 79 years. METHODS: This study involved 297 adults aged 40 to 79 years from Tongzhou District in Beijing and Taiyuan City in Shanxi Province. Static balance was assessed using a one-legged stance test with eyes closed (performed on either the left or right foot), measured by the duration participants could maintain the position. Spatial-temporal gait parameters, including step time, step length, gait speed and cadence, were collected using an accelerometer (Xsense Dot, Netherlands) under two conditions: single-task (walking 20 meters in a straight line on flat ground) and dual-task (walking while performing a random subtraction of three-digit numbers). Restricted cubic splines (RCS) were applied to explore potential dose-response relationships between static balance and gait performance. RESULTS: The average age of the participants was 53.6±11.0 years. Under the single-task condition, the step time was 0.48±0.09 s, step length was 0.66±0.11 m, gait speed was 1.12±0.18 m/s, and cadence was 124.0±17.7 counts/min. Under the dual-task condition, the step time was 0.49±0.08 s, step length was 0.63±0.09 m, gait speed was 1.03±0.19m/s, and cadence was 119.5±16.9 counts/min. Significant differences were observed in gait parameters between single-task and dual-task conditions (P<0.05). After adjusting for covariates, no significant linear trends were found between one-legged stance duration with eyes closed and any gait parameters under the single-task condition (P>0.05). For the dual-task condition, linear regression analysis revealed that, compared to the lowest quartile of standing time (Q1) of standing time, there was a significant positive correlation between standing time in Q2 (P=0.039) and Q3 (P<0.001) with step time. Additionally, a positive association was observed between standing time in Q3 (P=0.027) and step length. However, no significant linear relationship was found between standing duration and gait speed or cadence (P>0.05). RCS analysis indicated a nonlinear relationship between one-legged stance duration and dual-task step time (P for nonlinear=0.029). Specifically, a standing time of less than 12.4s was negatively correlated with step time, while a standing time greater than 12.4s was positively correlated with step time. This suggests that 12.4s may represent a minimum threshold for improved dual-task step time performance. CONCLUSION: Static balance ability was associated with gait parameters under dual-task conditions in adults aged 40-79 years. A dose-response relationship was identified between one-legged standing duration and step time, particularly during dual-task conditions. To mitigate age-related declines in gait parameters, middle-aged and older adults should prioritize improving static balance ability, as it plays a critical role in maintaining walking capacity and overall mobility.
Read CV wang chenglongECSS Paris 2023: OP-MH25
INTRODUCTION: The use of force-velocity profiling to assess individual physical capacities has gained considerable interest in geriatric screenings over the past few years (e.g., Alcazar et al., 2023). Recent studies have applied this approach to knee extensor muscles using isokinetic devices (e.g., Piche et al., 2021). However, interpreting isokinetic torque-velocity profiles in older adults remains challenging due to the lack of reference values for key parameters (e.g., theoretical maximal torque [T0] and velocity [V0]). Moreover, the functional significance of these parameters is still unclear. METHODS: A cross-sectional study was conducted on 959 French older adults (272 men, 687 women) aged 65–99 years. Relative knee extensor peak torque was measured at six isokinetic angular velocities (30°/s, 60°/s, 90°/s, 120°/s, 150°/s, 180°/s). Absolute torque data were expressed relative to participants’ body mass, allowing for the identification of isokinetic torque-velocity profiles and extraction of key parameters (e.g., T0, V0). In addition, comfortable walking speed was assessed using a 10m OptoGait walkway, and frailty status was determined. Participants were stratified by sex and age in 5-year increments, except for the 90–100 age group. Age-related differences in isokinetic parameters were analyzed using one-way ANOVAs separately for men and women. Furthermore, Pearson correlations were performed between walking speed and parameters derived from isokinetic torque-velocity profiles to explore their functional relevance. RESULTS: Statistical analyses revealed a progressive ≃50% decline in absolute and relative isokinetic torque values in both men and women, starting at 75 years of age. Normalizing torque to body mass reduced disparities between adjacent age groups. While force-related parameters (e.g., T0) showed a significant decline with age, velocity-related parameters (e.g., V0) remained statistically unchanged. Thus, aging, irrespective of sex, altered the force-velocity profile by flattening its shape and reducing force-related values. Additionally, moderate but significant correlations were found between comfortable gait speed and force-related derived from torque-velocity profiles. CONCLUSION: This study provides updated sex- and age-specific reference values for key isokinetic knee extensor torque-velocity parameters in older adults. Our findings suggest that force-related parameters derived from isokinetic torque-velocity profiles are functionally relevant, whereas velocity-derived parameters might not correspond to physiological indices. 1. Alcazar et al. J Cachexia Sarcopenia Muscle, 2023 2. Piche et al. Exp Gerontol, 2021
Read CV Flavio Da SilvaECSS Paris 2023: OP-MH25
INTRODUCTION: Sarcopenia (i.e., the age-related muscle mass and muscle strength loss) can lead to disabling consequences in older adults [5] as well as sarcopenic obesity (i.e., when increased adipose tissue accompanies sarcopenia) that is considered a strong and independent risk factor for frailty, diverse comorbidities and mortality [2, 3]. Evidence suggests that exercise reduces body fat and improve muscle strength and mass in older people in community dwelling settings [1]; however, it is not completely clear if daily physical activity (PA) is beneficial enough to prevent sarcopenia and sarcopenic obesity in this population [4]. The aim of this study was to analyse the cross-sectional associations of daily accelerometer-measured PA with sarcopenia, sarcopenic obesity and their components in older adults. METHODS: We analysed data from 2628 older adults (65-94 years) from the Seniors-ENRICA-2 cohort study collected from 2015 to 2017. Participants wore the Actigraph GT9X Link accelerometer on their non-dominant wrist for seven consecutive days, removing it only for water-based activities. The average daily acceleration and steps were used as reliable proxies of daily PA. Muscle strength was evaluated using a hand grip dynamometer (HGS) and the sit-to-stand test (StoS). Fat mass (FM%) and skeletal muscle mass adjusted by height (SMM/height) and weight (SMM/weight) to characterize sarcopenia and sarcopenic obesity respectively, were estimated by bioelectrical impedance analysis. Sarcopenia and sarcopenic obesity were treated as continuous variables, standardized to Z-scores. Associations between the study variables were examined using linear regression models adjusted for main covariates. RESULTS: Daily acceleration in mg and a 1000-step increase showed an inverse association with StoS (s) [unstandardized ß (95%CI): -0.05 (-0.07, -0.03) and -0.08 (-0.11, -0.04) respectively]. Inverse associations were observed between daily acceleration and FM% [unstandardized ß (95%CI) -0.04 (-0.08, -0.00)] and between daily steps and SMM/height (kg/m2) [unstandardized ß (95%CI)-0.03 (-0.06, -0.01)]. No significant associations were observed between PA and HGS, SMM/weight or the sarcopenia and sarcopenic obesity scores. CONCLUSION: Daily PA, as assessed by accelerometer, was directly associated with muscle strength and inversely with fat mass in older adults. Although PA does not seem to be directly related to sarcopenia and sarcopenic obesity in this population, it is related to some of their components. References: 1. Axelrod, C. L., et al., Metabolism, 2023 2. Donini et al., Obes Facts., 2022 3. Moreno-Franco et al., Sci Rep, 2018 4. Sánchez-Sánchez, J. L., et al., The Lancet Healthy Longevity, 2024 5. Xia, W., et al., BMC Musculoskeletal Disorders, 2024
Read CV Julia WiedmaierECSS Paris 2023: OP-MH25