Associations among manual wheelchair fit, supraspinatus tendon properties, scapular kinematics, and shoulder pain in young adult manual wheelchair users

Introduction Shoulder pain is highly prevalent in manual wheelchair users (MWUs), so clinical guidelines for manual wheelchair prescription and fitting aim to preserve upper limb function. Subacromial impingement may be a common cause of shoulder pathology and is associated with high supraspinatus occupation ratio (OR) and scapular kinematics. However, manual wheelchair fit parameters, supraspinatus OR, and scapular kinematics have not been well explored in pediatric and young adult MWUs. Purpose The purpose of this cross-sectional, observational study was to explore the correlations between manual wheelchair parameters, and shoulder pain in young MWUs and explore the potential casual mediation of supraspinatus OR and scapular kinematics in the manual wheelchair fit-shoulder pain relationship. Materials and Methods Twenty-two (n=22) adolescent and young adult MWUs were recruited. Reflective markers were affixed to participants’ upper extremities, torso, and manual wheelchairs. Participants sat comfortably and propelled their wheelchair using a self-selected speed and propulsion technique to obtain manual wheelchair fit parameters and upper extremity kinematics. The supraspinatus tendon and subacromial space were imaged with B-mode ultrasound in the Crass and mock push positions. Using digital calipers on ImageJ, average tendon thickness was obtained based on three points along the tendon. A single measurement was used to determine acromiohumeral distance (AHD). Occupation ratio was calculated as a ratio of the thickness compared to the AHD. Shoulder pain was quantified using the Wheelchair User Shoulder Pain Index (WUSPI) and Shoulder Pain and Disability Index (SPADI). Spearman correlations and quadratic regressions were performed to explore the associations between several manual wheelchair fit parameters and shoulder pain. Two causal mediation analyses were performed on significant manual wheelchair fit-shoulder pain relationships with peak scapular rotation during propulsion or supraspinatus OR as mediators. Results Rear wheel toe angle was significantly and linearly correlated with WUSPI and SPADI scores with toe-in associated with greater pain. Scapular kinematics and supraspinatus OR showed no relationship with toe angle. Elbow angle at top-dead-center was significantly correlated with WUSPI and SPADI scores in quadratic models. Scapular kinematics showed no mediating effect on the elbow angle – shoulder pain relationship. Supraspinatus OR was not related to elbow angle. Seat dump, seat/shoulder width, rear wheel camber, and anterior-posterior axle position relative to the shoulder were not significantly correlated to shoulder pain. Conclusion Manual wheelchair setup has few associations with shoulder pain in pediatric and young adult MWUs, though elbow angle and toe angle had significant, moderate correlations with pain. Supraspinatus OR was not related to any manual wheelchair fit parameter, and AC kinematics did not mediate the relationship between manual wheelchair parameters and pain. These analyses suggest that the role of manual wheelchair fit in shoulder pain and health-related quality of life may be different in children and young adult MWUs compared to mature adult MWUs; however, more research is needed to better understand the associations between manual wheelchair fit parameters and shoulder pain in this unique clinical population.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Tran, Dustin Fan

Contributors dc:contributor

• Hanks, Matthew M
• Rice, Laura A

• wheelchair setup
• rotator cuff
• occupation ratio
• shoulder impingement
• upper extremity
• propulsion
• biomechanics
• disability
• rehabilitation

Statement dc:rights

• Copyright 2025 Dustin Tran

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129260

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129260