The relationship between functional upper limb kinematics, pain and perceived disability in individuals with rheumatoid arthritis

Abstract

Shoulder motion is needed to perform essential independent living tasks such as feeding and bathing. Rheumatoid arthritis (RA) of the shoulder joint can result in pain and stiffness that may interfere with performance of such activities. This study compared the upper limb kinematics of a control group and a group of subjects with RA primarily affecting the glenohumeral joint, and examined the relationship between upper limb kinematics, pain and perceived disability in the RA group. Motion about four upper limb joints while performing various tasks (lifting two items to shoulder height, combing hair, touching back of opposite scapula and touching sacrum) was filmed using a three-dimensional motion analysis system. Data was collected from the RA subjects on their perception of the magnitude of upper limb pain (visual analog scale) and on their self stated ability to perform tasks of daily living (Health Assessment Questionnaire - HAQ and the Canadian Occupational Performance Measure - COPM). Results showed few differences in range of motion (ROM), maximum angular velocity and maximum angular acceleration between the groups during performance of the five functional tasks. The magnitude of upper limb pain was not associated with the functional ROM used by the RA group, however the magnitude of upper limb pain was positively correlated to the HAQ. Upper limb pain was negatively associated with maximum angular acceleration. Functional ROM used was not related to the HAQ. A comparison between the HAQ and the COPM revealed some conceptual differences. Although a direct relationship between functional upper limb kinematics, pain and perceived disability in individuals with rheumatoid arthritis was not found, various significant associations were discovered which warrant further study and definition of the factors which influence the study variables.