Archives of Physical Medicine and Rehabilitation
Volume 88, Issue 4 , Pages 456-463, April 2007

Upper-Limb Joint Power and Its Distribution in Spinal Cord Injured Wheelchair Users: Steady-State Self-Selected Speed Versus Maximal Acceleration Trials

  • Robert Price, MSME

      Affiliations

    • Department of Rehabilitation Medicine, University of Washington, Seattle, WA
    • Corresponding Author InformationReprint requests to Robert Price, MSME, Dept of Rehabilitation Medicine, University of Washington, Box 356490, 1959 NE Pacific St, Seattle, WA 98053
    • ,
  • Zachary R. Ashwell, MSME

      Affiliations

    • Department of Rehabilitation Medicine, University of Washington, Seattle, WA
    • ,
  • Michael W. Chang, MD, PhD

      Affiliations

    • Department of Rehabilitation Medicine, University of Washington, Seattle, WA
    • ,
  • Michael L. Boninger, MD

      Affiliations

    • Human Engineering Research Laboratories, Veterans Affairs Pittsburgh HealthCare System, Pittsburgh, PA
    • Departments of Rehabilitation Science and Technology and Bioengineering, University of Pittsburgh, Pittsburgh, PA
    • Department of Physical Medicine and Rehabilitation, University of Pittsburgh Medical Center Health System, Pittsburgh, PA
    • ,
  • Alicia M. Koontz, PhD, RET

      Affiliations

    • Human Engineering Research Laboratories, Veterans Affairs Pittsburgh HealthCare System, Pittsburgh, PA
    • Departments of Rehabilitation Science and Technology and Bioengineering, University of Pittsburgh, Pittsburgh, PA
    • ,
  • Sue Ann Sisto, PT, MA, PhD

      Affiliations

    • Department of Physical Medicine and Rehabilitation, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ
    • Kessler Medical Rehabilitation Research and Education Corp, West Orange, NJ.

Abstract 

Price R, Ashwell ZR, Chang MW, Boninger ML, Koontz AM, Sisto SA. Upper-limb joint power and its distribution in spinal cord injured wheelchair users: steady-state self-selected speed versus maximal acceleration trials.

Objective

To compare upper-limb joint power magnitude and distribution between the shoulder, elbow, and wrist during maximal acceleration (MAC) versus steady-state, self-selected speed (SSS) manual wheelchair propulsion.

Design

Cross-sectional biomechanic study.

Setting

Research university and teaching hospital.

Participants

Volunteer sample of 13 manual wheelchair users with spinal cord injury below T1.

Interventions

Not applicable.

Main Outcome Measures

Propulsive joint power magnitude and fractional distribution among upper-limb joints.

Results

Wilcoxon signed-rank testing revealed shoulder power was larger for MAC versus SSS (median peak, 101.5W; interquartile range [IQR], 74.6; median peak, 37.7W; IQR, 22.9; respectively) (P<.01). Elbow and wrist power were unchanged. Peak shoulder power fraction was larger for MAC versus SSS (median peak, 1.055; IQR, .110 vs peak, .870; IQR, .252) (P<.01). Peak elbow power fraction was smaller for MAC versus SSS (median peak, −.012; IQR, .144 vs peak, .146; IQR, .206) (P<.05). Peak wrist power fraction was smaller for MAC versus SSS (median peak, −.058; IQR, .057 vs peak, −.010; IQR, .150) (P<.05).

Conclusions

Power at the shoulder was larger than at other joints. Peak shoulder joint power and power fraction was larger during MAC versus SSS propulsion. Elbow and wrist power fractions were smaller for MAC versus SSS propulsion. Higher joint power, present under MAC, may predispose manual wheelchair users to injury, particularly at the shoulder.

Key Words: Biomechanics, Kinetics, Movement, Rehabilitation, Wheelchairs

 

 Supported by the National Institute on Disability and Rehabilitation Research (grant no. H133A011107).

 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 author(s) or upon any organization with which the author(s) is/are associated.

PII: S0003-9993(07)00024-X

doi:10.1016/j.apmr.2007.01.016

Archives of Physical Medicine and Rehabilitation
Volume 88, Issue 4 , Pages 456-463, April 2007

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