Effects of whole-body vibration on balance and mobility in institutionalized older adults: a randomized controlled trial

Objective: To investigate whether a comprehensive exercise program was effective in improving physical function among institutionalized older adults and whether adding whole-body vibration to the program conferred additional therapeutic benefits. Design: A single-blinded randomized controlled trial was conducted. Setting: This study was carried out in residential care units. Participants: In total, 73 older adults (40 women, mean age: 82.3 ± 7.3 years) were enrolled into this study. Interventions: Participants were randomly allocated to one of the three groups: strength and balance program combined with whole-body vibration, strength and balance program without whole-body vibration, and social and recreational activities consisting of upper limb exercises only. All participants completed three training sessions per week for eight weeks. Outcome measures: Assessment of mobility, balance, lower limb strength, walking endurance, and self-perceived balance confidence were conducted at baseline and immediately after the eight-week intervention. Incidences of falls requiring medical attention were recorded for one year after the end of the training period. Results: A significant time × group interaction was found for lower limb strength (five-times-sit-to-stand test; P = 0.048), with the exercise-only group showing improvement (pretest: 35.8 ± 16.1 seconds; posttest: 29.0 ± 9.8 seconds), compared with a decline in strength among controls (pretest: 27.1 ± 10.4 seconds; posttest: 28.7 ± 12.3 seconds; P = 0.030). The exercise with whole-body vibration group had a significantly better outcome in balance confidence (pretest: 39.2 ± 29.0; posttest: 48.4 ± 30.6) than the exercise-only group (pretest: 35.9 ± 24.8; posttest: 38.2 ± 26.5; P = 0.033). Conclusion: The exercise program was effective in improving lower limb strength among institutionalized older adults but adding whole-body vibration did not enhance its effect. Whole-body vibration may improve balance confidence without enhancing actual balance performance.