HIP ABDUCTOR EXERCISE AND LATERAL STABILITY IN OLDER ADULTS AT RISK OF FALLS.

Abstract

Purpose/Hypothesis: Impaired lateral stability may contribute to falls in older adults. Maintenance of lateral stability requires the hip abductor muscles to generate force rapidly and with precise coordination. The purpose of this study was to obtain preliminary data on the effects of a 10-week program of high-velocity resistance training using a lateral trainer in older adults at increased risk for falls. Subjects: Twenty-one community-dwelling older adults between the ages of 74 and 93 years participated in the study. All subjects were identified as being at increased risk of falls on the basis of clinical balance test scores. Materials/Methods: Subjects were randomized to exercise (n=10, mean age 84.50 ± 5.58 years) and control (n=11, mean age 83.55 ± 3.24 years) groups. Exercise group subjects performed lateral trainer exercise 3 times per week for 10 weeks. Control group subjects were asked to maintain their regular physical activity and exercise levels. Balance confidence, hip abductor maximal muscle strength and rate of force development, clinical balance test performance (Four Square Step Test, Single Limb Stance, 360° Turn) and walking speed were evaluated at pre-, mid- (5-week) and post-intervention sessions. Linear mixed model analyses were applied to estimate means of outcome variables by group and time. Results: One subject in the exercise group withdrew after midintervention testing. Exercise group subjects who completed the intervention attended at least 85% of the exercise sessions (at least 25 sessions). No significant adverse events occurred in association with the intervention. Compared to control group subjects, exercise group subjects demonstrated faster performance on the 360° Turn after intervention (p=.0131). No other significant between-group differences were found. Conclusions: Lateral trainer exercise can be performed safely by older adults. Although subjects in the exercise group demonstrated improved performance on one dynamic balance test after the intervention, the lack of other between-group differences suggests limited effectiveness of lateral trainer exercises when performed in isolation. Lateral trainer exercise may be beneficial as one component in a multifaceted intervention program. Clinical Relevance: Lateral trainer exercise may help to increase rapid, dynamic turning ability in older adults at risk of falls.