Longitudinal change in thigh muscle strength prior and concurrent to a @entity922 worsening or improvement in knee function - Data from the XXXX Initiative.

@entity1 @entity571 @entity922
OBJECTIVE: To test whether a clinically relevant change in knee function is associated with concurrent or prior change in thigh muscle strength. METHODS: 2675 @entity571 Initiative @entity1 (1485 @entity1 /1190 @entity1 ) with measurements of isometric muscle strength at baseline (BL), year 2 (Y2) and 4 (Y4) follow-up were divided into those with greater than @entity922 ( @entity922 ) worsening (>= 6/68 in WOMAC function) during Y2 > Y4, @entity922 improvement, or without relevant change. Changes in isometric muscle strength, concurrent (Y2 > Y4) and preceding (BL > Y2) function change, were compared between groups using ANCOVA. RESULTS: Concurrent loss in extensor muscle strength in @entity1 with worsening knee function during Y2 > Y4 differed significantly (p=0.03) from that in @entity1 without change (-4.6% 95% CI[-6.8, -2.4]) vs. -2.2% 95%CI[-3.0, -1.4]) and so did the concurrent increase in strength in those with functional improvement (+2.2% 95%CI[-0.3, 4.7]; p<0.0001). This increase in strength remained significantly different after adjusting for covariates but was preceded by a greater loss in strength (-7.7% 95%CI[-10.3, -5.0]; p=0.02) during BL > Y2 compared to those without function change during Y2 > Y4 (-4.3% 95%CI[-5.2, -3.4]). The strength decrease during BL > Y2 in those with worsening knee function during Y2 > Y4 (-4.5% 95%CI[-6.9, -2.2]) did not significantly differ (p=0.87) from those without change in function. No differences between changes in flexor muscle strength were observed between groups. CONCLUSION: The findings suggest a positive concurrent longitudinal association between change in extensor muscle strength and worsening/improvement in knee function in KOA. However, a corresponding change in muscle strength was not observed to precede change in function. This article is protected by copyright. All rights reserved.
