Shoulder rotational strength, movement, pain and joint tenderness as indicators of upper-extremity activity limitation in moderate rheumatoid arthritis

In this study 32 women were investigated in order to elucidate how shoulder rotational muscular strength and upper-extremity impairments are associate d with activity limitation in moderate rheumatoid arthritis. A regression a nalysis was carried out to determine whether these variables could indicate the outcomes of a shoulder-arm disability questionnaire (SDQ) comprising t hree parts, plus parts of the Health Assessment Questionnaire, the Function al Status Questionnaire and the Sickness Impact Profile. Shoulder-arm and w rist movements were moderate-to-good (r = 0.53, p < 0.01 and r = 0.58, p < 0.01, respectively) in relation to isometric internal rotational strength. The relationship between isokinetic concentric and eccentric internal rotat ional strength was moderate-to-good (r = 0.59, p < 0.01). Isokinetic eccent ric internal rotation strength, shoulder-arm movement, joint tenderness and pain variables together indicated 25-61% (adjusted R-2) Of the variation i n SDQ, Eccentric strength had the highest adjusted R-2 (41%) in relation to SDQ 1, covering mainly personal hygiene. Shoulder rotational strength did not indicate the more general instruments, Thus, hand and elbow impairments also are probably important in explaining activity limitations.