The purpose of this study was to investigate the effects of balance exercise and elastic-resistance exercise programs on the muscle strength and balance of the old-old elderly. The INT 1 group showed a statistically significant improvement in muscle strengths of five of seven muscle groups, but not those of the knee flexors and ankle plantar flexors. Compared to the mean muscle strengths of the CON group, after the balance exercises, the INT 1 group showed statistically significant improvements in the strengths of the five muscle groups. After conducting balance exercises for seniors over the age of 65, Kim and Lockhart14) reported an improvement in muscle strength and gait and concluded that balance exercises contributes to fall prevention. The INT 2 group showed a statistically significant improvement in the strength of all seven muscle groups after the intervention. In the comparison of mean muscle strengths with those of the CON group, after the resistance exercises, the INT 2 group showed significant improvements in the strengths of all seven muscle groups. This result is in accordance with the results of Zion et al.12), who conducted elastic-resistance exercises over the course of 8 weeks for the elderly and found that muscle strength and balance showed statistically significant improvements. Kim and Lockhart14) reported that the ankle plantar flexor and knee extensor strengths of 18 older adults improved after performance of elastic-resistance exercises for 8 weeks. As people age, the risk of fall increases because a decrease muscle mass leads to atrophy, which decreases muscle function15). Strengthening exercises using elastic resistance are practical because they have only a small risk of injury, provide consistent tension, and are easily portable and inexpensive. Elastic-resistance exercises help not only in rehabilitation but also in other areas because they have been proven to improve muscle strength and stability16). The INT 1 and INT 2 groups showed significant improvements in balance after the intervention, which proves that both balance exercises and resistance exercises are effective at improving balance. In the posttest comparison of the mean differences in balance among the three groups, no difference was found between the INT 1 and INT 2 groups,
but both groups showed significant improvements in comparison with the CON group. Age-related balance deficits may occur because of increased postural sway caused by weakness of leg muscles and decreased proprioception17). The balance exercises and elastic-resistance exercises conducted for 8 weeks improved leg muscle strength and proprioception of the neuromuscular system through muscle contraction and stimulation of proprioceptive sense. Lee and Park18) reported that improvement in the strength of the lower extremities enhances the balance of the elderly. We assume that the improvement in balance observed in the present study resulted from the improvement seen in the strength of the lower limbs. Unlike previous studies that have reported fall-prevention exercises to be ineffective for the old-old elderly8, 9), our results show that balance exercises and elastic-resistance exercises were effective at improving the muscle strength and balance of this population. Skelton and Beyer19) indicated that there are limits to the effectiveness of fall-prevention exercises for the old-old elderly, and noted that one-onone approaches for the elderly are more effective than group exercises. In our study, the intervention was conducted for the old-old elderly, who have a rapid aging process, and thus are the most vulnerable to falls. Our results show there were improvements in both the balance exercise and resistance exercise groups after 8 weeks. Although the elasticresistance exercises proved to be more effective than the balance exercises at strengthening the ankle plantar flexors, there was not a big difference in the effectiveness of the two exercise types; thus, we conclude that both types of exercise are acceptable as fall-prevention exercises for the old-old elderly. We also suggest that these exercises be used appropriately according to personal physical characteristics and needs. Because of the physical characteristics of the elderly, fall-prevention exercises should not pose injury risks, and should be easy to practice, even at home. The balance exercises and elastic-resistance exercises used in the present study are accessible to the elderly, because they do not need specialized equipment and can be adjusted to personal physical strength. A limitation of this study was that the group exercises with the researcher were conducted for only 2 of the 5 intervention days per week, leaving 3 days per week for the elderly to perform the exercises by themselves. This made it difficult to control the intervention perfectly. The significance of this study is that it revealed that balance exercises and elastic-resistance exercises are effective at fall prevention for the old-old elderly, who are at high risk of falls because of rapid aging. Therefore, such exercises are suggested for fall prevention programs for this particular population.