16 Nov Causes of lower back pain 2/2
The beauty of the Thomas test is that it can help identify dysfunctions in both the 1 joint and 2 joints hip flexors.
Tightness within the illiopsoas muscles (1 joint hip flexors) presents as seen on picture B. Where the tested limb is forced into hip flexion, instead of remaining flat on the bed as seen on picture A.
Whilst the individual in picture A is showing adequate illiopsoas muscle length but tightness within the Rectus Femoris (2 joint hip flexor). This is illustrated by the lower leg not being parallel with the legs of the bed but instead the knee is forced into extension.