By: Lynda Bennett
Original article: Sadeghi M, Sawatzky B. Effects of vibration on spasticity in individuals with spinal cord injury: a scoping systemic review. American Journal of Physical Medicine and Rehabilitation. 2014 April. Find the original article here.
If you have ever had a spasm, a sudden involuntary muscle movement or contraction, you’ll know that it’s not a pleasant experience. Unfortunately, up to 78% of individuals with a spinal cord injury (SCI) experience numerous episodes of spasticity. Not only does it cause pain and fatigue, interfere with one’s ability to sit, transfer and wheel, it also causes ensuing negative self-image. In addition, there is the ever-present possibility of developing muscle deformities and skin wounds. So the question is, what are possible solutions that can alleviate these consequences?
What are the present-day solutions to spasticity?
Managing spasticity involves a wide range of approaches, including medication, surgery, and physical therapy. The least invasive of these is physical therapy, which is often used as in combination with either medication, surgery, or both.
Physical therapy strategies include strengthening, stretching, weight bearing, electrical stimulation, splinting, heat/cold therapy, and braces. It also includes both whole-body vibration (WBV) and focal vibration (FV), where vibrations are transferred to the human body and can be used to manage spasticity in individuals with SCI. However, WBV and FV treatments have not been adopted into clinical practice guidelines, despite published research on its application and efficacy. Why is this so? This review endeavors to uncover what is known about vibration therapy and to offer recommendations on how to proceed, by summarizing and analyzing the results of previous studies.
How were spasticity research selected for review?
To identify research on spasticity, the researchers conducted a directed, systematic investigation of relevant reports published since 1946 via major medical electronic databases.
Research selected for this review was based on the following criteria:
- Three or more participants of 17 years or older with chronic SCI for at least four months.
- Includes assessments of muscle tightness , passive movement resistance, involuntary muscle activity, spasm frequency, muscle stretch and other reflexes.
- Measurement of the frequency of vibration.
From a total of the 109 articles found on spasticity, only 10 met all the criteria. The selected studies included 195 participants with acute or chronic SCI of varying severity and 87 able-bodied participants.
What did the review discover?
The review revealed evidence that suggests a link between WBV/FV and the reduction of spasticity. However, there was also some evidence that vibration could induce spasticity in some individuals. The review also found considerable variability in the vibration types and frequencies used in these studies, making it difficult to form broad conclusions without more accurate data. These findings signify the need for more and better studies on factors such as vibration frequency level and duration.
What do these findings mean?
The findings indicate that vibration, both whole-body and focal, can play a role in reducing spasticity in individuals with SCI. The review cannot support WBV and FV therapies in managing spasticity because there were no randomized controlled trials nor larger sample size studies used.
Analysis of the studies reveals that FV and WBV can both reduce spasticity for brief periods. Further research in this area could potentially lead to a properly adjusted vibrator, with defined frequencies and intensities to manage spasticity. However, an evidence-based relationship between vibration frequencies and their impact on spasticity cannot yet be fully established.
What are the limitations of this study?
This review revealed that the current knowledge of vibration effect on spasticity is quite limited. The results underlined the need for clinicians and researchers to perform more comprehensive, randomized, and controlled trial studies on vibration using more individuals, in order to provide clearer directions in the use of vibration on spasticity.