Measures in EMG in one-arm drive wheelchairs

Manual wheelchair propulsion is known to be an inefficient means of ambulation which has been associated with high a prevalence of upper limb injuries. Such injuries are thought to occur from a combination of repetitive movements, heavy loads on the extremities, upper limb weakness and inefficient propulsive technique. Hemiplegic users are particularly vulnerable to upper limb injury because of being reliant on only one arm for propulsion. Literature reports that nearly 70% of wheelchair users experience upper extremity pain or overuse injury at some point.

This research project was funded by PMG.

Project aims

The aim of this pilot study was to compare EMG activity in six muscles surrounding the shoulder joint during propulsion of three different Action3 manual one arm drive wheelchairs:

  • a NuDrive lever attached to one wheel
  • the Neater Uni-wheelchair
  • a standard Action3 wheelchair.

Each wheelchair was steered using the Neater Uni-wheelchair steering mechanism attachment. Surface EMG was measured during dynamic propulsion of each wheelchair during propulsion around an indoor circuit and obstacle course.

Seventeen non-disabled users were randomly assigned each wheelchair. During propulsion a multiple sensor, continuous measurement of force was recorded. The EMG data was measured using the biometrics data link system v 7.5 and the data was measured at 1000 Hz. The EMG electrodes were attached according to Seniam guidelines. Time taken to complete different sections of the circuit were recorded.

Mean activity levels for each muscle were calculated per user per wheelchair.

Project impact

The NuDrive produced the highest levels of activity in triceps muscle in straight running. The NuDrive produced the highest levels of activity biceps and Pectoralis major over mats and around corners.

The Neater produced the lowest levels of activity in biceps and Pectoralis major over mats and around corners. There was no significant difference in activity in the other muscles in the different wheelchairs.

The evidence suggests that the NuDrive is the least efficient to propel and the Neater generated the least force during the slalom and over mats. The evidence would suggest the need to replicate the study in a user population is warranted. There were no obvious confounding variables to explain this pattern however, from experience and observation during the data collection it was noted that some individuals struggled with propelling the NuDrive particularly over the different surfaces. This may be explained through variation in body proportion, muscle strength, or co-ordination issues within these individuals.

Research team

Anne Mandy

Output

Final Paper (PDF)