In the Thomas Test, bottom position deviation of the femur laterally indicates tightness of which muscle group?

• A. Tensor Fasciae Latae
• B. Iliotibial Band
• C. Tightness of Tensor Fasciae Latae
• D. Adductor Magnus

Answer: (C)

The test looks at how the hip muscles influence the position of the leg when one hip is flexed to shorten the hip and flatten the spine. If the bottom leg drifts out to the side (lateral deviation) when you let the knee of the other leg come toward the chest, it points to tightness in muscles that pull the thigh outward. The Tensor Fasciae Latae is a primary hip flexor and abductor; when it’s tight, it tends to pull the femur into abduction, causing that lateral deviation. The iliotibial band isn’t a muscle, so while it can be involved with lateral pull, the muscle most directly implicated here is the Tensor Fasciae Latae. Adductor Magnus would pull the thigh inward, not outward, so it doesn’t fit the finding.