Effect of ultrasound on mobility in osteoarthritis of the knee. A randomized clinical trial

Ultrasound increases soft tissue extensibility and may be an effective adjunct in the treatment of knee contractures secondary to connective tissue shortening. A randomized clinical trial was conducted to determine the effectiveness of ultrasound in relieving stiffness and pain in patients (age mean = 67.5 years, SD = 13.0) who had osteoarthritis (OA) and a chronic knee contracture. Subjects received 12 treatments of exercise preceded by either ultrasound (n = 34) or sham ultrasound (n = 35) and a blinded evaluation at baseline, after treatment, and 2 months after treatment. MANCOVA controlling for baseline scores showed that there were no significant differences in knee active range of motion (ROM) (goniometry) or pain (visual analogue scale) between experimental and control groups. Possible explanations for the no difference finding involve dosage issues, muscle shortening, transiency of effects, and the effects of exercise. Paired t-tests revealed that both groups significantly improved (p less than 0.05) in active ROM, pain, and gait velocity, and maintained improvement for at least 2 months. Although ultrasound may not contribute to the management of patients with chronic knee stiffness and OA, benefits of the exercise program and increased activity secondary to program participation probably influenced the overall improvement.