Quadriceps Strength Does Not Decrease With Knee Osteoarthritis Progression: 1660: Board #10 May 27 3:30 PM - 5:00 PM

Thomas, Abbey C.; Sowers, MaryFran; Karvonen-Gutierrez, Carrie; Palmieri-Smith, Riann M.

Medicine & Science in Sports & Exercise: May 2009 - Volume 41 - Issue 5 - p 87
doi: 10.1249/01.MSS.0000354825.43635.ef
B-23 Free Communication/Poster - Biomechanics: MAY 27, 2009 1:00 PM - 6:00 PM ROOM: Hall 4F

University of Michigan, Ann Arbor, MI.

(Sponsor: Christopher D. Ingersoll, PhD, ATC, FACSM)

Email: abbeyt@umich.edu

(No relationships reported)

Quadriceps weakness has been implicated as a potential risk factor for the development and progression of knee osteoarthritis (OA); however minimal data are available to demonstrate quadriceps dysfunction is present during the early stages of the disease. Further, if quadriceps weakness is a major determinant of disease progression it follows that muscle strength may diminish as OA severity worsens, but evidence supporting this hypothesis is lacking.

PURPOSE: To determine if quadriceps strength decreases as OA severity increases.

METHODS: Ninety-one women (age 56.49±2.8 yrs; height 1.63±0.07 m; mass 83.51±14.12 kg) participated in this study and underwent radiographic evaluation and strength testing. Semi-flexed standing A-P x-rays were taken and graded for tibiofemoral OA severity using the Kellgren-Lawrence scale. Quadriceps strength was assessed isometrically at 90°. Subjects performed three maximum voluntary isometric knee extension contractions and the peak torque values from those trials were averaged. Statistical analysis was performed via a 1×5 ANOVA.

RESULTS: Quadriceps strength (Nm/kg) was not statistically different between the five OA grades (P > 0.05) (Figure 1). While there appears to be a modest decline in strength associated with great knee OA severity (grade 4), the test for trend was not statistically significant (P = 0.09).

CONCLUSION: Contrary to our hypothesis, quadriceps weakness did not worsen with increasing OA severity. Albeit the data come from a cross-sectional study design, absence of a statistically significant association calls into question the importance of quadriceps strength in the etiology of tibiofemoral osteoarthritis.

Supported by The Michigan Arthritis Foundation (N007718)

©2009The American College of Sports Medicine