Comparison of muscle density, size, strength, and functional mobility between female fallers and non-fallers

Abstract

Imaging based muscle density (MD) is associated with poor lower extremity performance, the development of mobility impairments, frailty, and hip fracture. These associations are all related to falls, yet no studies have investigated MD in community dwelling fallers. The primary objective of this study was to determine whether lower leg MD differed between community dwelling elderly women who do and do not report falls. The secondary objective was to determine if lower leg muscle cross sectional area (MCSA), timed up & go (TUG) test, and relative grip strength (RGS; as a ratio to body mass) differed between fallers and non-fallers. Women (N = 135), 60 years or older (mean age 74.1, SD 7.6) were recruited from a random sample of Saskatoon residents. Fallers (n = 36) and Non-fallers (n = 99) were grouped based on 12-month retrospective falls survey response. A peripheral quantitative computed tomography (pQCT) scan of the non-dominant lower leg was acquired to determine MD and MCSA. Participant age, height, weight, TUG test result and RGS were recorded. Between-group differences in mean age, body mass index (BMI), MD, MCSA, TUG and RGS were compared using independent t-tests (P < 0.05). MD and TUG results were transformed to meet the assumption of normality for parametric analysis. Age, BMI, MCSA and RGS did not differ (P > 0.5). Fallers had 3.2% lower MD (P = 0.01) and 15.1% slower TUG scores (P = 0.02), than non-fallers. Muscle density may serve as a physiological marker for the assessment of muscular health and fall risk in community dwelling elderly women.