Relative proprioceptive weighting ratio of the muscle spindles in old-old lumbar spinal disease patients with a history of falls assessed by local vibratory stimulus

[Purpose]: We investigated the relationship between fall history and center of gravity sway when vibratory stimulus was applied to the multifidus and triceps surae. [Subjects]: The subjects were 17 old-old lumbar spinal disease inpatients (9 males, 8 females; average age 79.4 ± 3.1 years). [Methods]: A vibratory stimulus of 60 Hz was alternately applied to the multifidus and triceps surae while the subjects stood with their eyes closed. We divided the subjects into fall and no-fall groups and compared the relative proprioceptive weighting ratios (RPW), number of falls, cross-sectional areas of the lumbar spine muscles, skeletal muscle volume, and the abdominal and spinal muscle strengths. We also determined whether on not there was a correlation between RPW and the number of falls. [Results]: The RPW of the fall group showed a decline in lumbar proprioception, and a postural strategy prioritizing the lower leg. A correlation was found between RPW and the number of falls. [Conclusion]: Our results suggest RPW is an assessment index which is related to falls.