[The relevance of muscle strength--extensors of the knee on pain relief in elderly people with knee osteoarthritis].

The main aim of this study was to evaluate muscle strength after short-term exercise program by elderly people with knee osteoarthritis that usually non exercising and to estimate if this change have influence on decrease of the pain. This study was longitudinal experiment that involved thirty participants aged 61-80 years with clinical signs and radiographic evidence of knee OA stage Kellgren II and III. They completed individual strengthening program knee muscle stabilisator and hydrotherapy in the pool during two weeks. Muscle strength and pain was estimated pre and post experimental time. The results are analysed by SPSS programme, version 15.0 for Windows. Values demonstrated decreasing degrees of the pain and increasing of muscle strength. The pain decreased 33% in advance, final pain oposite initial estimated 2.4 degrees smaller by VAS. Muscle strength for stronger leg was (initial/final) 93.10/106.33 kg/cm2 (t-test 3.584*, p < 0.001), and for weak leg 71.93/83.37 kg/cm2 (t-test 3.118* p < 0.004). Regression analysis gave small valuables of determination coefficient (R2 of 0.014-0.081) and regression coefficient (B of 0.004-0.015) for stronger and weaker leg. Exercises produced significant increase in muscle strength and decrease in pain in OA of the knee. Hypothesis that increase of muscle quadriceps strength have influence on decrease of the pain in the knee is not confirmed.