DOI
https://doi.org/10.25772/KB36-RY11
Defense Date
2025
Document Type
Thesis
Degree Name
Master of Science
Department
Biomedical Engineering
First Advisor
Carrie Peterson
Abstract
Introduction The majority of manual wheelchair users (MWUs) with spinal cord injury or disorder (SCI/D) develop shoulder pain. In adults with SCI/D, there is evidence that upper limb strength imbalances are associated with shoulder pain. However, strength imbalances may indicate protective compensatory strategies, and other factors may be important contributors to pain. Currently, personalized prevention and management of pain is limited, little is known about joint strength imbalances and pain in children who use manual wheelchairs, and the effect of the age of SCI/D onset is poorly understood. The purpose of this study was to assess the effect of age of SCI/D onset on isometric joint strength imbalances, shoulder pain, and relationships between strength imbalances and pain.
Methods Forty-seven MWUs were recruited and participated. Participants were subdivided into one of three subgroups: 12 pediatric participants, 17 adults with pediatric-injury onset, and 17 adults with adult-injury onset. Participants performed maximum voluntary isometric contractions while seated in a dynamometer to measure maximum isometric joint moments in seven arm postures. Each participant performed three maximum contractions for 3-5 seconds. Shoulder pain was quantified using the Wheelchair User’s Shoulder Pain Index (WUSPI) questionnaire, a validated self-report measure. WUSPI scores range from 0 to 150, with a larger score indicating greater pain. The Kruskal-Wallis H test was used to evaluate differences in WUSPI scores and strength ratios across groups. Spearman’s rank correlation was used to examine the relationships between WUSPI scores and shoulder strength ratios.
Results Shoulder pain was prevalent in each group; shoulder pain was not different across the groups stratified by age of SCI/D onset (p = 0.288). The elbow flexion/extension moment ratio differed by group, being greatest in the adults with pediatric-onset SCI (p = 0.0489). No other differences in moment ratios were found across the groups, although the shoulder flexion/extension moment ratio was nearly significant (p = 0.0562), demonstrating the same trend across groups as elbow flexion/extension (i.e., being greatest in the adults with pediatric-onset SCI). Joint moment ratios and shoulder pain were not correlated.
Conclusions Children and adult participants with SCI/D experienced similar severity of shoulder pain, suggesting the need for a greater understanding of pain in children, and interventions to reduce the risk for shoulder pain. Isometric strength imbalances differed in groups stratified by age of SCI/D onset, but the strength imbalances we tested were not directly correlated with shoulder pain. Thus, a multivariate approach is needed to assess relationships between strength imbalances and pain to account for covariates such as age, sex, body mass, and years of wheelchair use.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-11-2025