Physical activity (PA) has been widely recommended as an effective intervention for the conservation of musculoskeletal (MS) health. (Borer, 2005) The decline of the MS system with ageing is a primary concern for scientists due to the reduced ability to contract the appropriate muscles in order to rotate the bones about the joints to enable functional movement. To assess the relationship between PA and self-selected habitual walking speed, we attached an activity (ActivPal) monitor to the thigh of 24 older people and also determined their self-selected habitual walking speed over 25m. Data were recorded for 5 complete consecutive days and the stepping time and step count were analysed.
A moderate and significant correlation was found between walking speed and time in stepping (TS) (r = 0.441; P = 0.031) and step count (SC) (r = 0.513; P = 0.01). To assess if ageing altered the mechanical load and musculoskeletal health, we attached an accelerometer (MSR) to the back of 15 young and 17 old participants and quantified the intensity of the loading.
Knee extensor strength was measured using an isokinetic dynamometer while bone density was measured using the Broadband Ultrasound Attenuation (BUA) of the calcaneus. A significant difference was found in the exposure to vigorous activity and in knee extensor strength between the young and old groups.