Effect Of Power Assistive Exercise On Muscular Strength In Elderly Women

Abstract

A prominent age-associated malady is the 40%-50% loss of muscle strength and compromised muscle strength and stability is associated with a frequency of falls. Resistance training is an effective means to reverse muscle atrophy in the elderly; however, elderly may be hesitant in engaging in traditional weight training. Standard weight lifting to those unfamiliar with resistance training can be both intimidating and hazardous. Power assistive exercise allows participants to apply force with, rather than against the movement of motorized levers. Thus, reducing the chance of injury and allowing the participant to work at his/her own comfort level, yet requiring muscle contractions. PURPOSE: To assess the effectiveness of power assisted exercises on muscle strength and functional capacity of elderly participants. METHODS: Female subjects (N=49) (Mean age 79.4 ±9.8 yrs) were separated into control (C=12) and exercise (E=27) groups. The E group trained 12 weeks, 2/wk for 30 min per session. Training involved six machines designed for trunk, upper and lower body muscles. Pre- and post- measures were collected on: arm curl (AC), bench press (BP), leg extension (LE), triceps extension (TE), chair stand (CS), and balance (BL). Data were treated with repeated measures ANOVAs. RESULTS: Analysis yielded significant E group improvements in the all variables: arm curl (p=0.0050), bench press (p<0.000), leg extension (p<0.000), triceps extension (p<0.000), chair stand (p=0.003), and balance (p<0.000) when compared to the control group. CONCLUSIONS: Proportional E group improvements were: AC= 30%, BP= 53%, LE = 24%, TE = 22%, CS = 35% and BL = 33%. While the increase in strength was noteworthy, the significant enhancement in balance was an additional benefit. Correlations between leg strength and balance were significant, suggesting that improvement in leg strength paralleled an increase in stability as measured by the Berg's Balance Scale. The use of the power assisted machines provides a safe alternative to improve both strength and balance in the elderly.