Ten Minutes of Passive Hip and Knee Joint Movement Reduces Stiffness Due to Osgood‐Schlatter Disease in the Rectus Femoris Muscle

Purpose To investigate the acute effects of passive movement on rectus femoris (RF) stiffness, flexibility, and subjective knee joint pain in patients with Osgood‐Schlatter disease (OSD). Methods Patients with bilateral OSD at the orthopedic clinic between July 2023 and June 2025 were prospectively enrolled. One foot was randomly assigned to the intervention group (10 minutes of passive hip and knee joint movement), and the other was assigned to the control group (10 minutes of rest). The acute effects before and after the intervention (PRE and POST, respectively) were compared. RF stiffness was assessed PRE and POST using shear modulus values, heel‐buttock distance, and subjective pain. A stratified cluster analysis of the treatment effect was performed based on the PRE shear modulus values in the intervention group (high‐value and low‐value groups). Results Fifty‐three participants diagnosed with bilateral OSD participated in the study. The RF shear modulus significantly decreased following the intervention (21.0 ± 4.4‐17.5 ± 3.2 kPa) ( P < .001), with the high‐value group (–20.1 ± 9.6%) showing a significantly greater effect than the low‐value group (–13.8 ± 8.6%) ( P = .022). Depending on the threshold, 83.0% exceeded the minimal detectable change at the 95% confidence level, and 86.8% exceeded the smallest worthwhile change (0.2 standard deviation), while 66.0% exceeded the more conservative smallest worthwhile change (0.5 standard deviation). Heel‐buttock distance and subjective pain significantly improved after passive movement (heel‐buttock distance: 12.5 ± 4.7 to 9.3 ± 3.4 cm; subjective pain: 4.2 ± 2.4 to 2.6 ± 2.0 cm) (both P < .001). None of the parameters changed significantly in the control group. Conclusions Ten minutes of passive hip and knee joint movement reduced RF stiffness in patients with OSD and improved knee joint flexibility and subjective pain. Furthermore, passive movement showed the greatest effect in the high‐value shear modulus group. Level of Evidence Level II, prospective comparative study.