Effects Of Jump Training On Postural Balance And Leg Muscle Function In Healthy Older Adults

Abstract

Age-associated loss of skeletal muscle strength and postural balance are critical determinants of independent daily living activities in later life. PURPOSE: This study aimed to investigate the effects of different jumping exercise tempos on static balance and leg muscle function in healthy older adults. METHODS: Twenty-six community-living older adults were randomly assigned to a quick 108 per minute tempo (QJ; n = 14; 6 men) or slow 60 per minute tempo [AS1] (SJ; n = 12; 5 men) jumping exercise group. Both groups performed one set of jumps until they reached a level of exertion they perceived as difficult (Borg-RPE Scale of 15). Both groups trained three times a week for 12 weeks and participated in 60-min supervised group exercise sessions at a local health center. Outcome measures included center of foot pressure (CoP) sway parameters during quiet standing with eyes open (EO) and eyes closed (EC), four-square step (FSS), two-step stride length (TSL), and rate of force development (RFD) for vertical ground reaction force in sit-to-stand movement. RESULTS: Repeated-measures analysis of variance showed a significant main effect for FSS (P = 0.009) and TSL (P = 0.002). After the training period, QJ demonstrated a significantly decreased FSS time (5.17 ± 1.00 vs. 4.87 ± 1.00 s, P < 0.05) and SJ demonstrated a significantly increased TSL (210.8 ± 21.1 vs. 227.3 ± 27.2 cm, P < 0.05). Both groups showed no changes in CoP sway parameters with EO or EC in quiet standing. CONCLUSIONS: Jumps at a quick tempo improved dynamic standing balance evaluated by the FSS, while jumps at a slow tempo improved leg muscle strength. Thus, 12 weeks of jump training at different tempos appeared to have no effects on quiet standing balance, but different effects on dynamic standing balance and leg muscle strength in healthy older adults. [AS1]The phrase 'per minute' was included for one group only, but the meaning was not clear. Please check my suggested alterations.