Effect of high-speed power training on muscle performance, function, and pain in older adults with knee osteoarthritis: a pilot investigation.

Objective: To examine the effect of high-speed power training (HSPT) on muscle performance, mobility-based function, and pain in older adults with knee osteoarthritis.
Methods: Thirty-three participants (mean ± SD age 67.6 ± 6.8 years) were randomized to HSPT (n = 12), slow-speed strength training (SSST; n = 10), or control (CON; n = 11) for a 12-week intervention. HSPT performed 3 sets of 12-14 repetitions at 40% of the 1-repetition maximum (1RM) "as fast as possible," SSST performed 3 sets of 8-10 repetitions at 80% of the 1RM slowly, and CON performed stretching and warm-up exercises. Outcome measures included leg press (LP) 1RM and LP peak power (PP) from 40-90% of the 1RM and the corresponding PP velocity (PPV) and PP force; 400-meter walk, Berg Balance Scale, and timed chair rise; and self-reported function and pain using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Analysis of variance models were used to compare changes from baseline to 12 weeks. Statistical significance was accepted at P < 0.05.
Results: LP PP improved in both HSPT and SSST compared to CON (P = 0.04). LP PPV improved only in HSPT (P = 0.01). There were also improvements in timed chair rise (P = 0.002), WOMAC function (P = 0.004), and WOMAC pain (P = 0.02) across all of the groups.
Conclusion: HSPT was effective at improving function and pain, but no more so than either SSST or CON. Because HSPT improved multiple muscle performance measures (strength, power, and speed), it is a more effective resistance training protocol than SSST and may increase safety in this population, especially when high-speed movements are required during daily tasks.
(Copyright © 2012 by the American College of Rheumatology.)