Effects of static stretching of knee musculature on patellar alignment and knee functional disability in male patients diagnosed with knee extension syndrome: A single-group, pretest–posttest trial

• Patellar tilt angle was increased in male Kext syndrome patients.
• Rectus femoris shortness had a significant effect on patellar tilt angle.
• Patella alta does not seem to be severe in male Kext syndrome patients.
• Stretching was effective in improving Kujala scores in male Kext syndrome patients.

BackgroundKnee extension (Kext) syndrome is based on movement system impairments and is described as knee pain associated with quadriceps stiffness.ObjectiveTo investigate the effects of 3 times per week for 4 weeks static stretching of knee musculature on patellar alignment and knee functional disability in male Kext syndrome patients.DesignA single-group, pretest–posttest clinical trial.SettingHazrat-e-Rasoul Akram Hospital.ParticipantsForty-six male Kext syndrome patients aged 18–35 years.MethodsKnee functional disability was assessed by the Kujala questionnaire. Patellar tilt was assessed using the skyline view X-ray. In addition, patella alta was assessed by X-ray using the Insall–Salvati ratio. After intervention, changes in knee flexion–extension range of motion (ROM) and hip adduction were assessed by goniometer and inclinometer. Changes in patellar tilt and patella alta were evaluated. Correlations between muscles length, patellar tilt and knee functional disability were also evaluated.ResultsThe mean of patellar tilt in male Kext syndrome patients was 15.19°. Only the correlation between rectus femoris shortness and patellar tilt (P = 0.002) and the correlation between rectus femoris shortness and knee functional disability (P = 0.037) were significant. Patella alta was not severe in male Kext syndrome patients (1.28 ± 0.10). Knee flexion–extension ROM and femoral adduction increased significantly after a 12-session stretching programme (P < 0.0001).ConclusionThe results demonstrated that rectus femoris shortness had higher correlation with patellar tilt and knee functional disability than iliotibial band and hamstring shortness. Stretching was effective in reducing patellar tilt, patella alta, knee functional disability, increasing knee ROM and hip adduction in these patients.