No abstract

Age-related muscle loss, termed sarcopenia, has been linked to an increased risk of falls, disability, and mortality. The purpose of this study was to develop a predictive measurement tool to estimate normalized fat-free mass index (FFMI), a means of identifying sarcopenia, in community-dwelling older adults. Functionally relevant measurements including mobility tests, food records, circumference measures, balance, and gait variables were included to ensure this model was comprehensive and accessible to clinicians. Eighty-five community-dwelling older adults (42 male) aged 75.2 ±5.7 years participated. Each completed two questionnaires regarding general health and physical activity levels. Anthropometric, strength, balance, gait, nutrition, and body composition tests were then conducted. A fat-free mass value, determined by bioelectrical impedance analysis, was normalized by height (FFMI). FFMI along with grip strength and gait speed was used to classify sarcopenia. FFMI was significantly correlated with all circumference measures (waist, arm, calf, and thigh) and body mass index (BMI), but no nutritional parameters. In males, maximum grip strength and a novel quiet balance measure, time outside of a 95 % confidence ellipse (TOE), were both positively correlated to FFMI. In females, age and double-support time correlated to FFMI. The prediction equation that accounted for the most variability of FFMI included the independent variables: sex, step time, BMI, and TOE (adjusted R 2 =0.9272). The proposed linear regression model can successfully predict FFMI values to a high level of accuracy in men and women. With this information, sarcopenia can be predicted by clinicians, and early interventions can be planned and implemented.

The objective of this work was to investigate the influence perturbation direction has on postural responses during overground gait, and whether these responses are age related. Differences in stepping patterns following perturbations of the support surface were examined in the frontal and sagittal planes during forward walking. Eleven young and 10 older adults completed Mini BESTest, hip strength tests, and 45 perturbed walking trials, triggered on heel contact. Lateral perturbations were more challenging to postural stability for both groups. Step length measures showed young adults recovered in the step proceeding the perturbation, while older adults needed additional steps to regain balance. Young adults arrested center of mass movement by producing larger step widths than older adults following the support surface perturbation.