Impact of pain reduction on muscular and functional performance in patients with knee osteoarthritis

الملخص EN

Objectives : This study aimed at studying the effect of pain reduction on periarticular muscle strength and muscle reflex activation as well as functional performance in patients with symptomatic knee osteoarthritis.

Methodology : Twenty five patients suffering from primary OA of the knee (s) and joint pain (aged 42 to 58 years) together with twenty healthy subjects matched in age, gender and body mass index were included in this study.

The severity of knee pain was evaluated by visual analogue scale (VAS).

Also pain severity impact on patient’s global activity of daily living was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index for pain scale (WOMAC).

Scoring of OA impact on Patient's functional status was determined by Lequesne's functional index.

Quadriceps muscle strength was assessed.

Surface electromyographic (SEMG) activity of the quadriceps and hamstrings muscles evoked by postural responses to sudden unpredictable forward and backward translation of the support surface was studied.

These data were measured at baseline and immediately after completion of 6 weeks of treatment program aimed at relieving knee (s) pain.

Quadriceps muscle strength and postural evoked response SEMG testing of quadriceps and hamstrings muscles were obtained from the control group as well.

Results : Patients showed significant reduction in their pain VAS score accompanied with reduction of WOMAC and Lequesne’s indices, increase in quadriceps muscle strength and improvement of postural evoked response of quadriceps and hamstrings muscles after 6 weeks treatment period.

Percent change in pain VAS correlated significantly with Percent change in WOMAC, Lequesne’s indices, quadriceps muscle strength and postural evoked SEMG parameters of quadriceps and hamstrings muscles.

Conclusions : Pain is a central determinant of disability in OA of the knee interfering with the voluntary and reflex control of peri-articular muscles.