5.1 Influence of Whole-Body Vibration Training Without Visual Feedback on Balance and Lower Extremity Muscle Strength of the Elderly

Journal: Medicine (Baltimore), 2016 Feb;95(5):e2709

Study Context: Balance deficit is one of the leading causes of falls in older adults. Aging induces the gradual decline of sensory functions, central processing, musculoskeletal and motor control, and neural pathways, thus leading to poor postural stability. Previous studies have also found that poor vision, restricted vision and declining depth perception are also closely related to body postural control.

This study randomly placed participants into one of three groups:

Group 1 performed a squat exercise on a vibration platform oscillating at 20 Hz with 4 mm displacement.

Group 2 performed the same squat exercise with the same parameters except they were blindfolded (visual feedback deprived).

Group 3 was the control group and they performed the same squat exercise except without any vibration and with the eyes open.

All three groups exercised for 5 minutes at a time, 3 times per week for 3 months.

Participants were retested at the end of the 3 month trial and again at 6 months. Testers were blind to the grouping of each subject.

Balance performance improved in both vibration training groups at 3 and 6 months compared to control and was significantly better again in the visual deprived group (blindfolded vibration training).

Strength performance remained the same in the control group. In the blindfolded vibration training group, knee extensor strength increased 37.89% and knee flexor strength improved 19.4%. In the eyes open vibration training group only knee extensor strength increased (15.4%).

At the 6 month follow-up, 0% of the eyes open vibration training group, 0% of the eyes closed vibration training group reported falls, whereas 28.57% of subjects from the control group reported hospital visits due to falls. (The average fall rate in adults over 65 is around 30%)

Comments: Previous studies have shown vibration training to improve strength and balance in older adults. Eliminating visual feedback, however, significantly improved both strength and balance performance during vibration training even more that vibration training with eyes open.

This suggests that we can utilize eyes closed vibration training for people whose goals include increased leg strength, balance and falls prevention.