The subject lay supine on a table so that the gluteal fold was located at the end
of the table and he held both knees to the chest. Then the right leg was lowered
until it came to rest and the subject was instructed to keep the leg as relaxed
as possible. Thomas test joint angles were calculated from a leg position
corresponding with a posterior pelvic tilt (lumbar spine on table), and was
defined as a horizontal alignment of the iliac crest and trochanterion
landmarks. If the alignment was judged as not being horizontal, the subject
was asked to move the contralateral knee closer to or further from the chest.