Comparison of instrument-assisted soft tissue mobilization and proprioceptive neuromuscular stretching on hamstring flexibility in patients with knee osteoarthritis

BACKGROUND: The association between hamstring tightness and knee osteoarthritis (KOA) is significant because tight hamstrings can put more strain on the knee joint, reduce its range of motion, and cause compensatory movements that worsen the KOA. OBJECTIVE: To compare the effects of instrument-assisted soft tissue mobilization (IASTM) and proprioceptive neuromuscular (PNF) on hamstring flexibility in patients with KOA. METHODS: Data for the randomized controlled trial (NCT05110326) was collected from n = 60 participants randomly divided into group A received IASTM and group B received PNF stretching. In group A, the therapist made 30 strokes gentle strokes with the tool from the origin to the insertion while holding the plane at a 45-degree angle over the treatment area. In group B, PNF stretching was done with three repetitions and 10 seconds rest between each, after isometric contraction of the hamstring muscle using approximately 50% of their maximum strength, holding it for 8 seconds, and then releasing it. A 30-minute session was given to each patient three times per week and was given for 6 weeks. Outcome measures were the visual analog scale (VAS) for pain intensity, the active knee extension test (AKET) for hamstring flexibility, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for the health status of KOA patients. RESULTS: The study found a significant interaction (p < 0.001) between interventions and time across several measurements. After 6 weeks, both interventions resulted in significant improvements (p < 0.001) across all dependent variables, with group A (IASTM) showing more significant improvement in hamstring flexibility, pain reduction, and health status (p < 0.001) compared to group B (PNF). CONCLUSIONS: Both the IASTM technique and PNF stretching resulted in increased hamstring flexibility, decreased pain, and enhanced general health. The IASTM technique, however, showed potential benefits over PNF stretching in terms of flexibility, pain relief, and public health enhancement. Physical therapists and manual therapists may prioritize the usage of the IASTM technique for patients who want to make significant changes in these areas.