Comparison of Kinematics, Kinetics, and EMG Throughout Wheelchair Propulsion in Able-Bodied and Persons With Paraplegia: An Integrative Approach

Abstract

A systematic integrated data collection and analysis of kinematic, kinetic, and electromyography (EMG) data allow for the comparison of differences in wheelchair propulsion between able-bodied individuals and persons with paraplegia. Kinematic data from a motion analysis system, kinetic data from force-sensing push rims, and electromyography data from four upper-limb muscles were collected for ten push strokes. Results are as follows: Individuals with paraplegia use a greater percentage of their posterior deltoids, biceps, and triceps in relation to maximal voluntary contraction. These persons also reached peak anterior deltoid firing nearly 10 deg earlier on the push rim, while reaching peak posterior deltoid nearly 10 deg later on the push rim. Able-bodied individuals had no triceps activity in the initial stages of propulsion while their paraplegic groups had activity throughout. Able-bodied participants also had, on average, peak resultant, tangential, and radial forces occurring later on the push rim (in degrees). There are two main conclusions that can be drawn from this integrative investigation: (1) A greater "muscle energy," as measured by the area under the curve of the percentage of EMG throughout propulsion, results in a greater resultant joint force in the shoulder and elbow, thus potentially resulting in shoulder pathology. (2) Similarly, a greater muscle energy may result in fatigue and play a factor in the development of shoulder pain and pathology over time; fatigue may compromise an effective propulsive stroke placing undue stresses on the joint capsule. Muscle activity differences may be responsible for the observed kinematic and kinetic differences between the two groups. The high incidence of shoulder pain in manual wheelchair users as compared to the general population may be the result of such differences, although the results from this biomedical investigation should be examined with caution. Future research into joint forces may shed light on this. Further investigation needs to focus on whether the pattern of kinematics, kinetics, and muscle activity during wheelchair propulsion is compensatory or evolutionary by tracking individuals longitudinally.

Effect of velocity on shoulder muscle recruitment patterns during wheelchair propulsion in nondisabled individuals: Pilot study

“…The semicircular technique is used widely in experienced wheelchair users, while nonusers implemented the arcing technique [38]. Results gained from studies with nondisabled subjects demonstrated the validity and reliability of EMG data in the measurement of muscle activity; the findings of the present study are certainly in-line with earlier research [39][40]. The level and timing of muscle recruitment in people who actually need to use a wheelchair are bound to show considerable variations depending on the type and level of each individual's injury [34].…”

Validation of a musculoskeletal model of wheelchair propulsion and its application to minimizing shoulder joint forces

“…The high incidence of shoulder pain in MWUs as compared to the general population may be the result of muscle activity differences as evidenced in our prior study (Dubowsky et al, 2008); however, further investigation into the connection between this link cannot be achieved without the aid of a computational model. The use of a fully validated patient-specific upper limb model will allow for the quantification of the magnitude of shoulder joint forces.…”

“…Investigating the magnitude of shoulder joint forces throughout propulsion may provide insight into the potential cyclic-propulsion and cumulative-trauma link. We have taken a two-pronged approach to investigate this possible connection, the first, looking at differences in experimentally collected data between able-bodied individuals and individuals with paraplegia (Dubowsky et al, 2008), and the second-the focus of the current study-creating and validating a computational upper-body model of WC propulsion for use in investigating the magnitude of shoulder joint forces.…”

A case report of shoulder fatigue imbalance in wheelchair rugby: implications to pain and injury

“…As a result, unnatural joint motion and stresses occur at the shoulder joint, increasing risk of pain and injury. 3,4 It is clear that continuous pushing, a common rehabilitation and post-rehabilitation therapeutic exercise, leads to agonistantagonist fatigue imbalance both acutely and chronically; however, the effects of alternative therapeutic exercises on fatigue imbalance, such as wheelchair sport, are just starting to be explored. It is unknown if wheelchair sport activity leads to greater, similar or lesser imbalance than typical therapeutic exercise (that is, continuous pushing).…”