Background: Various methods are used for recovery of knee flexion range of motion (ROM) due to a tightened rectus femoris muscle (RFM) or limited inferior glide of the patella. Stretching methods are common interventions for restoring the tightened RFM length. Also patellar inferior gliding (PIG) technique can recover tightened RFM length too. However, effect of applying the PIG to passive knee flexion (PKF) has not been studied.
Objects: The purpose of this study was to investigate the effect of combining PIG with RFM stretching for improving knee flexion ROM in subjects with RFM tightness.
Methods: Twenty-six subjects with RFM tightness were recruited. Two different methods of knee stretching were tested: 1) PKF during modified Thomas test (MTT) and 2) PKF with PIG during MTT. The passive stretching forces was controlled by hand-held dynamometer. The knee flexion ROM angle was measured by a MTT with ImageJ software. Differences between the conditions with and without PIG were identified with a paired t-test.
Results: The knee flexion ROM was significantly greater for PKF with PIG (114.44±9.33) than for PKF alone (108.97±9.42) (p<.001).
Conclusion: A combination of passive knee flexion exercise and PIG can be more effective than PKF in increasing knee flexion ROM in individuals with RFM tightness.

• Jun-hee Kim(Kinetic Ergocise Based on Movement Analysis Laboratory, Dept. of Physical Therapy, The Graduate School, Yonsei University)
• Moon-hwan Kim(Dept. of Rehabilitation Medicine, Wonju Severance Christian Hospital)
• In-cheol Jeon(Kinetic Ergocise Based on Movement Analysis Laboratory, Dept. of Physical Therapy, The Graduate School, Yonsei University)
• Ui-jae Hwang(Kinetic Ergocise Based on Movement Analysis Laboratory, Dept. of Physical Therapy, The Graduate School, Yonsei University)
• Oh-yun Kwon(Kinetic Ergocise Based on Movement Analysis Laboratory, Dept. of Physical Therapy, College of Health Science, Yonsei University, Dept. of Ergonomic Therapy, The Graduate School of Health and Environment, Yonsei University) Corresponding author