Effects of Controlled Whole-body Vibration Training on Balance and Fall Outcomes Among Healthy Older Adults: A 6-Week Pilot Study.

Background: Falling is the second leading cause of injury-related death worldwide and is a leading cause of injury among older adults. Whole-body vibration has been used to improve balance and reduce fall risk in older adults. No study has assessed if vibration benefits can be retained over time. Objectives: The aims of this study were to examine if six-weeks of whole-body vibration could improve balance and fall outcomes, and to assess if benefits associated with the training program could be sustained two months following the final training session. Design and Setting: Repeated measures randomized controlled design. Participants: Twenty-four independent living older adults were recruited and were randomly assigned to the whole-body vibration or control group. Intervention: Participants performed three sessions of whole-body vibration training per week with a vibration frequency of 20 Hz or with only an audio recording of the vibration noise. An assessment of balance and fall outcomes was performed prior to, immediately following, and two-months after the completion of the training program. Main Outcome Measures: Composite balance scores from the Berg Balance Scale and treadmill fall rates were assessed pre-training, post-training, and two-months post-training. Results: Seventeen participants completed the study. No between groups differences were found (p<0.05) in the measures of balance or fall rates. Conclusions: Findings revealed that six weeks of whole-body vibration was not effective in improving balance scores or fall rates.

Constraining eye movement when redirecting walking trajectories alters turning control in healthy young adults.

Humans use a specific steering synergy, where the eyes and head lead rotation to the new direction, when executing a turn or change in direction. Increasing evidence suggests that eye movement is critical for turning control and that when the eyes are constrained, or participants have difficulties making eye movements, steering control is disrupted. The purpose of the current study was to extend previous research regarding eye movements and steering control to a functional walking and turning task. This study investigated eye, head, trunk, and pelvis kinematics of healthy young adults during a 90° redirection of walking trajectory under two visual conditions: Free Gaze (the eyes were allowed to move naturally in the environment), and Fixed Gaze (participants were required to fixate the eyes on a target in front). Results revealed significant differences in eye, head, and trunk coordination between Free Gaze and Fixed Gaze conditions (p < 0.001). During Free Gaze, the eyes led reorientation followed by the head and trunk. Intersegment timings between the eyes, head, and trunk were significantly different (p < 0.05). In contrast, during Fixed Gaze, the segments moved together with no significant differences between segment onset times. In addition, the sequence of segment rotation during Fixed Gaze suggested a bottom-up postural perturbation control strategy in place of top-down steering control seen in Free Gaze. The results of this study support the hypothesis that eye movement is critical for the release of the steering synergy for turning control.