Increased Seat Dump Angle in a Manual Wheelchair is Associated with Changes in Thoracolumbar Lordosis and Scapular Kinematics during Propulsion

Publication date: Available online 18 March 2017
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Beth A. Cloud, Kristin D. Zhao, Arin M. Ellingson, Ahmad Nassr, Anthony J. Windebank, Kai-Nan An
ObjectiveTo quantify and compare spinal curvature and shoulder kinematics throughout the manual wheelchair propulsion cycle for individuals with spinal cord injury (SCI) who were seated at 2 different seat dump angles.DesignSingle-group, repeated-measures study.SettingAcademic medical center.ParticipantsTwenty-eight individuals completed the telephone screening; 21 were eligible and completed the study.InterventionsParticipants' personal manual wheelchairs were modified to have seat dump angles of 0° or 14°, with a vertical backrest. Participants completed at least 3 propulsion cycles in each condition, during which spine and shoulder motion data were collected with fiber optic and electromagnetic sensors, respectively.Main Outcome MeasuresThoracolumbar spinal curvature, glenohumeral kinematics, and scapulothoracic kinematics at the start of push (SP), mid push (MP), end of push (EP), and mid recovery (MR).ResultsParticipants had significantly less lordosis in the 14° condition for all propulsion events. Median differences ranged from 2.0° to 4.6°. Lordosis differences were more pronounced in those with low SCI. Scapulothoracic internal rotation was increased in the 14° condition at SP and MP (mean differences of 2.5° and 2.7°, respectively). Relative downward rotation increased in the 14° condition at SP and MP (mean differences of 2.4° and 2.1°, respectively). Scapulothoracic differences were more pronounced in those with high SCI. No glenohumeral rotations were significantly different between the conditions.ConclusionsScapulothoracic kinematics and spinal curvature differences during propulsion may be associated with the position of other body segments or postural stability. Because no differences were observed at the glenohumeral joint, risk of subacromial impingement may not be affected by this seat angle change.



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