The effects of a rotator cuff tear on activities of daily living in older adults: A kinematic analysis

Abstract

Rotator cuff tears (RCT) in older individuals may compound age-associated physiological changes and impact their ability to perform daily functional tasks. Our objective was to quantify thoracohumeral kinematics for functional tasks in 18 older adults (mean age=63.3±2.2), and compare findings from nine with a RCT to nine matched controls. Motion capture was used to record kinematics for 7 tasks (axilla wash, forward reach, functional pull, hair comb, perineal care, upward reach to 90°, upward reach to 105°) spanning the upper limb workspace. Maximum and minimum joint angles and motion excursion for the three thoracohumeral degrees of freedom (elevation plane, elevation, axial rotation) were identified for each task and compared between groups. The RCT group used greater minimum elevation angles for axilla wash and functional pull (p≤0.0124) and a smaller motion excursion for functional pull (p=0.0032) compared to the control group. The RCT group also used a more internally rotated maximum axial rotation angle than controls for functional reach, functional pull, hair comb, and upward reach to 105° (p≤0.0494). The most differences between groups were observed for axial rotation, with the RCT group using greater internal rotation to complete functional tasks, and significant differences between groups were identified for all three thoracohumeral degrees of freedom for functional pull. We conclude that older adults with RCT used more internal rotation to perform functional tasks than controls. The kinematic differences identified in this study may have consequences for progression of shoulder damage and further functional impairment in older adults with RCT.

Introduction

Sarcopenia and reduced strength are well-known sequelae of aging contributing to functional declines older adults experience (Clark and Manini, 2010). Presence of a shoulder injury, like a rotator cuff tear (RCT), can further reduce an individual׳s ability to perform functional tasks (Lin et al., 2008, van Schaardenburg et al., 1994). RCT is a common musculoskeletal injury for older adults, with prevalence increasing from 25.6% to 50.0% for adults in their sixties and eighties, respectively (Yamamoto et al., 2010). Shoulder injury may result in adaptive movements caused by muscle weakness or force imbalance (Lippitt and Matsen, 1993, Lippitt et al., 1993, Magarey and Jones, 2003, Phadke et al., 2009), or used as a pain avoidance strategy (Hall et al., 2011, Mell et al., 2005). In addition to limiting functionality, altered kinematics may expose the glenohumeral joint to new contact force scenarios, which could lead to further joint damage (Hsu et al., 2003, Vidt, 2014).

The upper limb is critical for daily functional tasks, including eating and personal hygiene (Katz et al., 1963). Studies evaluating upper limb functional task performance have primarily focused on younger or uninjured individuals (Magermans et al., 2005, Safaee-Rad et al., 1990, van Andel et al., 2008). Little work has focused on older adults (Hall et al., 2011) or investigated functional task performance in those with RCT. Therefore, our objective was to quantify thoracohumeral kinematics for a group of older adults with and without RCT during performance of functional tasks spanning the upper limb workspace. Kinematics for three thoracohumeral degrees of freedom were compared between groups. The null hypothesis was that task kinematics for RCT and control groups would not be different.