Differential Impact of Ageing on Proximal and Distal Musculature in Physically Active People

Abstract

Age-related decline in muscular force and power is an important prognostic indicator of functional impairments in older people. Most research has focused on the quadriceps and muscles which extend and flex the elbow and ankle joints as well as handgrip strength. To date, the strength of proximal and distal muscles of the upper limbs has not been compared in groups of active adults of differing ages. The aim of the study was to compare proximal muscles expressed as torques of extension of the arm (ArmExt) and distal muscles expressed as handgrip strength (HGS) in young and older physically active adults. This study examined 100 physically active volunteers without neuromuscular or central-nervous system disorders: 25 older males [OM] (68.3 ± 5.5 years) and 25 older females [OF] (67.0 ± 5.4) and a control group: 25 young males [YM] (21.2 ± 1.5) and 25 young females [YF] (21.3 ± 1.3). Strength measurements of the upper, dominant limb, were done under isometric contraction. The ArmExt measurement was done using Set Measurement Forces. For HGS measurement a hand dynamometer was used. The results showed no statistically significant differences in the ArmExt and ArmExt/kg of the OF and OM groups compared to the YF and YM groups, respectively. The HGS value for the OM group was statistically significantly lower than for the YM group. The HGS/kg in the OF and OM groups was statistically significantly lower than in the YF and YM groups, respectively too. Our results indicate a more pronounced effects of dynapenia being observed in distal muscles to compare with proximal ones in older physically active adults.