College of Massage Therapists of British Columbia (CMTBC) Practice Exam

During supine assessment of a patient with low back pain, increased lumbar lordosis occurs when one knee is brought to the chest. Which condition contributes to this presentation?

1. Sacroiliac joint dysfunction

2. Weakness in lumbar extensor muscles

3. Tight gluteus maximus in the bent leg

4. Iliopsoas contracture in the straight leg

The correct answer is: Iliopsoas contracture in the straight leg

Increased lumbar lordosis during supine assessment, particularly when one knee is brought to the chest, can be attributed to an iliopsoas contracture in the straight leg. The iliopsoas muscle group, which includes the psoas major and iliacus muscles, plays a crucial role in hip flexion and stabilization of the lumbar spine. When the knee is drawn to the chest, it causes the hip of the straight leg to extend. If the iliopsoas is contracted or tight on the straight leg side, it can pull the lumbar spine into a more pronounced lordotic curve. This occurs because the iliopsoas is a powerful hip flexor and stabilizer of the lumbar spine. A tight iliopsoas can cause an anterior pelvic tilt and accentuate lumbar lordosis as the hip flexes on the opposite side. In this context, the other options do not directly contribute to the increased lordosis in the same way. For instance, sacroiliac joint dysfunction may lead to pain or altered movement patterns but doesn't specifically generate the increased lordosis observed during this assessment. Weakness in the lumbar extensor muscles might contribute to a general lack of support for the spine, but not specifically to the increased lordosis