<p class="first" id="P1">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.
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