Wheelchair Vibration, Whole Body Vibration and Spasticity: A Study of the Influence of Wheel Design on Wheelchair Vibration and Whole Body Vibration as a Trigger of Muscle Spasms in Populations With Spinal Cord Injury

Links

Abstract

INTRODUCTION: The majority of individuals with chronic spinal cord injury (SCI) experience spasticity, which can often impair function and de- grade quality of life. Reports by individuals with SCI suggest that whole body vibration (WBV), as can occur while riding wheelchairs, may trigger spasticity.

OBJECTIVES: 1. Examine the influence of wheel design on wheelchair vibration. 2. Develop a system allowing exposure of individuals with SCI to WBV and analysis of muscle activity to identify spasticity.

METHODS: 1. A wheelchair wheel comparison study: Vibration acceleration and frequency content produced by wheelchairs equipped with 2 different wheel designs (steel spoked and composite material spoked) were compared as:

1a. 13 subjects with SCI wheeled through an obstacle course simulating a wheelchair user’s daily activities

1b. 22 non-SCI subjects wheeled down a ramp and over a vibration inducing obstacle.

Vibration acceleration was recorded using 2 accelerometers mounted on the wheelchairs’ main axle and footrest. The influence of wheelchair vibration on spasticity was assessed using questionnaires, completed by the SCI subjects.

2. A controlled whole body vibration (CWBV) pilot study: 2 SCI subjects were exposed to 10 WBV sessions. Each exposure consisted of a single frequency, lasted 20 seconds, and was repeated on 2 separate days. The WBV was applied using an electrodynamic shaker and the subjects’ leg muscles’ activity was recorded using an electromyography (EMG) system. Muscle spasms were identified by calculating the ratio between periods of increased muscle activity and the period before exposure to vibration.

RESULTS: No statistically significant differences (p=0.05) were found in wheelchair vibration acceleration or frequency content between the 2 tested wheel designs and no clear correlation between wheelchair vibration and spasticity was apparent. The CWBV system was able to apply vibration (±0.5Hz, ±0.001g) and record muscle activity (±7 mV). The CWBV exposures produced several muscle responses that were considered to be spasms.

CONCLUSIONS: The tested composite material spoked wheels do not differ, in vibration performance, from steel spoked wheels. The developed CWBV apparatus appears suitable for studying muscle activity in response to WBV.

Cited Works (9)

Year	Entry
2005	Bovenzi M. Health effects of mechanical vibration. G Ital Med Lav Ergon. January–March 2005;27(1):58-64.
2006	Pickett GE, Campos-Benitez M, Keller JL, Duggal N. Epidemiology of traumatic spinal cord injury in Canada. Spine. April 1, 2006;31(7):799-805.
1999	Bovenzi M, Hulshof CTJ. An updated review of epidemiologic studies on the relationship between exposure to whole-body vibration and low back pain (1986–1997). Int Arch Occup Environ Health. September 1999;72(6):351-365.
2008	Kiiski J, Heinonen A, Järvinen TL, Kannus P, Sievänen H. Transmission of vertical whole body vibration to the human body. J Bone Miner Res. August 2008;23(8):1318-1325.
1990	Griffin MJ. Handbook of Human Vibration. London, UK: Academic Press Limited; 1990.
1975	Kelsey JL, Hardy RJ. Driving of motor vehicles as a risk factor for acute herniated lumbar intervertebral disc. Am J Epidemiol. July 1975;102(1):63-73.
1997	De Luca CJ. The use of surface electromyography in biomechanics. J Appl Biomech. May 1997;13(2):135-163.
1993	Seidel H. Selected health risks caused by long-term, whole-body vibration. Am J Ind Med. April 1993;23(4):589-604.
2004	Kittusamy NK, Buchholz B. Whole-body vibration and postural stress among operators of construction equipment: a literature review. J Safety Res. 2004;35(3):255-261.