Effects of Different Stretching Techniques on the Outcomes of Isokinetic Exercise in Patients with Knee Osteoarthritis

TLDR

The study compared how different stretching techniques influence the outcomes of isokinetic muscle strengthening exercises in 132 patients with bilateral knee osteoarthritis. Participants were randomized into four groups—(I) isokinetic strengthening only, (II) static stretching plus isokinetic exercise, (III) proprioceptive neuromuscular facilitation plus isokinetic exercise, and (IV) control—and outcomes were assessed via Lequesne’s index, range of motion, visual analog pain scale, and peak muscle torques during knee flexion and extension. All treated groups showed significant pain and disability reductions and increased peak muscle torques, but only groups II and III improved range of motion and muscle strength at 60°/s, with group III achieving the greatest strength gains at 180°/s, indicating that stretching—especially PNF—enhances the effectiveness of isokinetic exercise in knee osteoarthritis.

Abstract

We recruited 132 subjects with bilateral knee osteoarthritis (Altman Grade II) to compare the effects of different stretching techniques on the outcomes of isokinetic muscle strengthening exercises. Patients were randomly divided into four groups (I–IV). The patients in Group I received isokinetic muscular strengthening exercises, Group II received bilateral knee static stretching and isokinetic exercises, Group III received proprioceptive neuromuscular facilitation (PNF) stretching and isokinetic exercises, and Group IV acted as controls. Outcomes were measured by changes in Lequesne's index, range of knee motion, visual analog pain scale, and peak muscle torques during knee flexion and extension. Patients in all the treated groups experienced significant reductions in knee pain and disability, and increased peak muscle torques after treatment and at follow‐up. However, only patients in Groups II and III had significant improvements in range of motion and muscle strength gain during 60°/second angular velocity peak torques. Group III demonstrated the greatest increase in muscle strength gain during 180°/second angular velocity peak torques. In conclusion, stretching therapy could increase the effectiveness of isokinetic exercise in terms of functional improvement in patients with knee osteoarthritis. PNF techniques were more effective than static stretching.