Effect of whole body vibration on cervical (neck) proprioception in young, healthy individuals serving as their own control: a pilot study.

Objective: The objective of this pilot study is to determine the effects of whole body vibration on head repositioning accuracy.

Methods: Twenty-one participants had a bicycle helmet with an attached laser pointer placed on their heads while standing on a vibration platform. After aligning the laser beam to their determined neutral position on wall-mounted chart paper, they were instructed to close their eyes, flex their neck maximally then return to their perceived neutral position. The point where the laser beam stopped as close to the neutral position as possible was marked on the chart and the sequence was repeated for extension, left and right rotation and left and right lateral flexion. The vibration platform was then activated and the process was repeated for the same six neck movements.

Results: T-tests showed significant differences (p < 0.01) for head repositioning errors between normal and vibration data for all neck movements (in mm), except flexion, with vibration trials exhibiting greater re-positioning errors. Data tabulated from the four Cartesian quadrants demonstrated a preponderance of overshoot re-positioning errors in which the laser stopped in individual Cartesian quadrants for each movement and each subject.

Conclusions: Whole body vibration contributes to greater head repositioning errors in young, healthy, asymptomatic individuals. Larger scale trials should establish a normal data base for head re-positioning with vibration. Future studies might investigate the relationship between whole body vibration on neck proprioception as an indicator of therapeutic efficacy in neck disorders.