What type of exercises should be performed?
Balance exercises involve maintaining standing and postural stability under a variety of conditions. A basic premise of exercise science is that in order to improve the function of a system through exercise, the exercise must stimulate that system (i.e., the principle of specificity). Therefore, in order to improve balance, the exercise intervention must target the systems that control balance (i.e., sensory and motor systems, among others). Challenging the sensory-motor systems can be accomplished with various exercise modalities. For example, several studies have shown that strengthening the lower extremity with elastic bands improves balance and prevents falls (Tinetti et al., 1994; Topp et al., 1996; Topp et al., 1993).
The effects of a 10-week program using inflatable 55-cm exercise balls (Thera-Band) on balance in older adults have been evaluated (Rogers et al., 2001). The program involved exercises in which the participants placed themselves in the prone, supine, or seated position on the balls and moved their bodies with the eyes open and closed over the ball's shifting base of support. As a result of the training, static balance, as measured by postural sway or instability, was reduced by approximately 10%. In addition, dynamic balance (functional reach) improved by 20% after training.
The effects of a 12-week intervention program using foam stability trainers (Thera-Band) and elastic resistance bands in older adults are also under evaluation (Shores et al., 2001). Participants shifted their body weight from foot to foot, and stood with the feet in a series of positions, including the feet side-by-side, the feet heel-to-toe, and on one foot. They also closed their eyes and/or moved the head to target the visual and vestibular systems. To progressively increase the difficulty of the exercises and target the somatosensory system, the participants performed the exercises while standing on the stability trainers. To enhance muscular strength, participants performed a series of elastic band exercises for the upper and lower body. Using a method called computerized force platform posturography, which assesses the limits of balance and stability (or how far one can lean in a given direction without stepping), we observed improvements in the directions that are most associated with falls that result in hip fracture (Greenspan et al., 1998), namely the right, left, and back directions. As a result of the intervention program, limits of stability improved by 67% in both the right/back and left/back directions. In the backward direction, there was a 77% improvement. In addition, the number of times a person could stand from a chair in 30 seconds increased by 17% (from 10.5 to 12.3 repetitions). No changes were observed in any of the balance or strength variables for the control group.
It is clear that certain exercise programs can improve balance by targeting the systems that control balance, specifically the visual, vestibular, somatosensory, and musculoskeletal systems. It is also clear that balance is an important factor in reducing the risk for falls.