Article
Wheelchair pushrim kinetics: Body weight and median nerve function,☆☆

https://doi.org/10.1016/S0003-9993(99)90082-5Get rights and content

Abstract

Objectives: Individuals who use manual wheelchairs are at high risk for median nerve injury and subsequent carpal tunnel syndrome (CTS). To gain a better understanding of the mechanism behind CTS in manual wheelchair users, this study examined the relation between (1) pushrim biomechanics and function of the median nerve, (2) pushrim biomechanics and subject characteristics, and (3) median nerve function and subject characteristics.

Design: Case series.

Setting: Biomechanics laboratory and an electromyography laboratory.

Participants: Thirty-four randomly recruited individuals with paraplegia who use a manual wheelchair for mobility.

Intervention: Subjects propelled their own wheelchair on a dynamometer at 0.9m/sec and 1.8m/sec. Bilateral biomechanical data were obtained using a force- and moment-sensing pushrim and a motion analysis system. Bilateral nerve conduction studies focusing on the median nerve were also completed.

Main Outcome Measures: Pearson's correlation coefficients between subject characteristics, median nerve conduction studies, and propulsion biomechanics; a regression model of nerve conduction studies incorporating subject characteristics and pushrim biomechanics.

Results: Subject weight was significantly related to median nerve latency (r = .36, p = .03) and median sensory amplitude (r = −.43, p = .01). Height was also significantly related to median sensory amplitude (r = −.58, p = .01). Subject weight was significantly related to the peak resultant force applied to the pushrim (r = .59, p < .001). Height, weight, and weight-normalized pushrim forces were successfully incorporated into a linear regression model predicting median sensory amplitude (r = .63, p < .05) and mean median latency (r = .54, p < .05).

Conclusion: This study found subject weight to be related to pushrim forces and median nerve function. Independent of subject weight, pushrim biomechanics were also related to median nerve function. Through weight loss and changes in pushrim biomechanics, it may be possible to prevent median nerve injury in manual wheelchair users.

References (32)

  • M Hagberg et al.

    Impact of occupations and job tasks on the prevalence of carpal tunnel syndrome [review]

    Scand J Work Environ Health

    (1992)
  • P Loslever et al.

    Biomechanical and epidemiological investigation of carpal tunnel syndrome at workplaces with high risk factors

    Ergonomics

    (1993)
  • BA Silverstein et al.

    Occupational factors and carpal tunnel syndrome

    Am J Ind Med

    (1987)
  • TJ Armstrong et al.

    Investigation of cumulative trauma disorders in a poultry processing plant

    Am Ind Hyg Assoc J

    (1982)
  • I Delgrosso et al.

    Carpal tunnel syndrome: role of occupation

    Int Arch Occup Environ Health

    (1991)
  • ML Boninger et al.

    3-D pushrim forces during two speeds of wheelchair propulsion

    Am J Phys Med Rehabil

    (1997)
  • Cited by (0)

    Supported in part by the US Department of Veterans Affairs Rehabilitation Research & Development Services (Project B689-RA), National Center for Medical Rehabilitation Research or the National Institutes of Health (NIH K08 HD01122-01, 5 P01 HD33989 03), and the Paralyzed Veterans of America.

    ☆☆

    No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.

    View full text