Neuromotor habituation as a mechanism for vibration induced low back pain.
Proceedings of the First American Conference on Human Vibration, June 5-7, 2006, Morgantown, West Virginia. Dong R, Krajnak K, Wirth O, Wu J, eds., Morgantown, WV: Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2006-140, 2006 Jun; :35-36
Occupational exposure to whole body vibration has long been associated with increased incidence of low back pain and low back injuries. A number of studies have investigated transmissibility of seat pan vibration. While transmissibility has been well researched, the mechanism by which vibration may induce injury has not been thoroughly studied. Winter et al. identified increased reflex response delay after vibration exposure and speculated that muscular fatigue may be the cause of this increase. However, a mechanism has yet to be demonstrated completely. A potential mechanism that may explain the increased risk is neuromotor habituation. Muscle spindle organs have been shown in the extremities to be sensitive to muscle and tendon vibration. Rapid length changes in muscle have been shown to result in kinesthetic illusions as the regular firing of the muscle spindles is interpreted as muscle lengthening. These illusions have also been demonstrated in the paraspinal musculature. With removal of vibration, research in the extremities has demonstrated increased positioning errors, probably due to neuromotor habituation. In this research, it has been hypothesized that neuromotor habituation after exposure to occupational vibration will increase positioning errors. It is further hypothesized that these errors can be shown to be linked to increased reflex response time. Such increased reflex response time could, in turn, decrease spinal stability and increase low back injury risk.
Neuromotor-function; Neuromuscular-system; Biomechanics; Biokinetics; Muscle-function; Sensory-motor-system; Vibration-effects; Reflexes; Injury-prevention; Back-injuries
Proceedings of the First American Conference on Human Vibration, June 5-7, 2006, Morgantown, West Virginia
University of Kansas Lawrence