Sitting with the trunk at 90 deg to the femur takes forces off the rectus femorus and tends to allow it to shorten, long term or short term.
My son-in-law, a software engineer, tested his posture for a tight rectus femorus. He could comfortably do the standing quad stretch with his pelvis tilted back from straight
, no problem.
This website provided has a simple 5 minute test specifically for the rectus femorus and flexibility in this area. Lying on a table, etc. Do you pass that test?
The Thomas test
I'm not familiar with this test. I show tight rectus femorus on the standing quad test as on the other site, the test that my son-in-law breezes through. I wish someone had told me about this posture issue many years ago.......did it contribute to my knee injuries?........