An estimated 265,000 Americans currently live with a disability related to an SCI, and 12,000 new cases of SCI occur in the United States each year. SCI often results in permanent damage to the body’s limbs. In some injuries, SCI can lead to partial or complete paralysis and loss of feeling. However, SCI can also cause debilitating spasms and stiffness in affected muscles.
Researchers supported through the National Center for Medical Rehabilitation Research are working to understand how SCI changes the underlying biology of affected nerves and muscles. This knowledge may help develop new ways to treat damaged tissue to improve the symptoms of SCI.
Scientists believe that muscle spasms in many SCI patients can happen when spinal neurons provide too much stimulation to the muscles they normally activate. This over-excitation results in spasms and stiffness. Researchers applied vibration—which has been shown to reduce muscle excitation—to the lower leg muscles of SCI patients and non-SCI volunteers.
The two groups showed similar reductions in muscle excitation. However, the effect lasted longer in the non-SCI volunteers. Moreover, in the muscles affected by SCI, vibration also increased expression of genes related to healing and growth of neurons.
These findings have encouraged researchers to begin further testing to help determine if treating affected muscles with repeated vibration could promote healing and reduce muscle spasms and stiffness in SCI patients (PMID: 21963319).