Predicting maximal strength of quadriceps from submaximal performance in individuals with knee joint osteoarthritis
Version of Record online: 28 JAN 2011
Copyright © 2011 by the American College of Rheumatology
Arthritis Care & Research
Volume 63, Issue 2, pages 216–222, February 2011
How to Cite
McNair, P. J., Colvin, M. and Reid, D. (2011), Predicting maximal strength of quadriceps from submaximal performance in individuals with knee joint osteoarthritis. Arthritis Care Res, 63: 216–222. doi: 10.1002/acr.20368
- Issue online: 28 JAN 2011
- Version of Record online: 28 JAN 2011
- Accepted manuscript online: 1 OCT 2010 02:08PM EST
- Manuscript Accepted: 23 SEP 2010
- Manuscript Received: 2 DEC 2009
- Maori Education Trust Scholarship
To compare the accuracy of 12 maximal strength (1-repetition maximum [1-RM]) equations for predicting quadriceps strength in people with osteoarthritis (OA) of the knee joint.
Eighteen subjects with OA of the knee joint attended a rehabilitation gymnasium on 3 occasions: 1) a familiarization session, 2) a session where the 1-RM of the quadriceps was established using a weights machine for an open-chain knee extension exercise and a leg press exercise, and 3) a session where the subjects performed with a load at which they could lift for approximately 10 repetitions only. The data were used in 12 prediction equations to calculate 1-RM strength and compared to the actual 1-RM data. Data were examined using Bland and Altman graphs and statistics, intraclass correlation coefficients (ICCs), and typical error values between the actual 1-RM and the respective 1-RM prediction equation data. Difference scores (predicted 1-RM − actual 1-RM) across the injured and control legs were also compared.
For the knee extension exercise, the Brown, Brzycki, Epley, Lander, Mayhew et al, Poliquin, and Wathen prediction equations demonstrated the greatest levels of predictive accuracy. All of the ICCs were high (range 0.96–0.99), and typical errors were between 3% and 4%. For the knee press exercise, the Adams, Berger, Kemmler et al, and O'Conner et al equations demonstrated the greatest levels of predictive accuracy. All of the ICCs were high (range 0.95–0.98), and the typical errors ranged from 5.9–6.3%.
This study provided evidence supporting the use of prediction equations to assess maximal strength in individuals with a knee joint with OA.