Biomechanical validation of upper extremity exercise in wheelchair users: design considerations and improvements in a prototype device

Abstract

Purpose. To develop guidelines for proper exercise execution on a novel device and to recommend design changes to the device based on biomechanical data and user feedback.

Method. Seven manual wheelchair users were instructed on proper exercise technique with a novel device, which allows a person to complete a seated row. Kinematics and kinetics of the dominant upper limb and trunk were measured with motion capture and electromyography data were collected on selected muscles.

Results. All subjects were able to exercise on the device with a mean power of 21.3 W (SD 7.1 W). Subjects did not keep the elbows close to the trunk during the drive phase of the row; rather, they moved from mean 75° (SD 12°) shoulder flexion to mean 62° (SD 11°) shoulder abduction. Identified problems included difficulty gripping the hand grips and user stability within the wheelchair.

Conclusions. The accessory unit should be adjustable to accommodate a wide range of user sizes and abilities. Proper exercise execution is important to maximise the potential benefit and minimise risk of injury. When executed properly, this exercise may benefit wheelchair users by improving cardiovascular fitness and strengthening muscle groups linked to the reduction of shoulder pain.

Keywords:

• Upper extremity
• wheelchair
• shoulder pain
• exercise
• universal design

Acknowledgements

Funding for this research was provided by NIDRR grant H133E070029. The sponsor was not involved in the study design, collection, analysis and interpretation of data, writing of the manuscript, or in the decision to submit the manuscript for publication. Michael J. Scott, PhD and graduate students were responsible for the design and fabrication of the accessory unit. The 9500HR stationary cycle that was provided by Life Fitness. Ms. Christine Hofmann assisted with data collection.