A study on deterioration in proprioception related to low back pain and falls and postural sway response to local vibratory stimulation

The goal of our work was to develop a treatment system for restoring proprioception in patients experiencing low back pain and those who experience falls. For this purpose, we investigated postural sway during local vibratory stimulation in elderly people in the standing position by using our newly developed variable frequency vibratory stimulation device and a gravicorder. Vibratory stimulations of 30, 60, 150, or 240 Hz were applied to the patients' lumbar multifidus (LM) or gastrocnemius soleus muscles (GM). These frequencies were determined from eigen response frequencies for proprioception. The eigen response frequencies for the Meissner corpuscle, muscle spindle, and the Vater-Pacini corpuscles were 30, 60, and 240 Hz, respectively. The relative proprioceptive weighting ratios at 30 and 240 Hz were significantly different between elderly patients with and those without low back pain. On the other hand, the relative difference of center of pressure length of the LM at 30 Hz was significantly different between elderly patients with and those without a history of falls. Therefore, the Meissner and Vater-Pacini corpuscles may be deteriorated in patients with low back pain. The Meissner corpuscle in the lumbar region may be deteriorated in those who experience falls.