How to Locate, Test and Stretch the Psaos Muscle

About the Psoas Muscle

The psoas muscle, also known as the iliopsoas muscle, is a deep-seated muscle located in the lower part of the torso, stretching from the lumbar spine to the femur bone. It is one of the largest and most powerful muscles in the body, and plays a vital role in stabilising the spine and allowing movement in the hips and lower back.

The psoas muscle is made up of two distinct muscle groups, the iliacus muscle and the psoas major muscle, which originate from different parts of the pelvis but merge together to form the iliopsoas muscle. The iliacus muscle originates from the iliac fossa, a concave surface on the inner surface of the hip bone, and the psoas major muscle originates from the lumbar vertebrae of the lower back.

The psoas muscle runs down the front of the spine and connects to the lesser trochanter of the femur bone in the hip joint, allowing it to be involved in flexion of the hip joint. The muscle is responsible for several important movements, including lifting the leg, walking, and maintaining proper posture. It is also involved in stabilising the spine and preventing excessive curvature.

The Thomas Test

The Thomas Test is a physical examination technique used to assess the length and flexibility of the hip flexor muscles, including the psoas muscle. This test is commonly used by healthcare professionals, such as physical therapists, manual therapists, and athletic trainers to evaluate muscle imbalances and diagnose conditions related to the hip and lower back.

The Thomas Test is named after Dr. Hugh Owen Thomas, a prominent orthopedic surgeon from the late 19th century. The test involves having the patient lie on their back on a table, with their legs hanging off the edge. The patient is then instructed to bring one knee to their chest and hold it there, while the other leg remains straight and relaxed. The examiner then observes the position of the straight leg and assesses any changes that occur when the knee is released.

During the Thomas Test, the examiner is looking for several key signs that can indicate tightness or weakness in the hip flexor muscles, including the psoas. If the straight leg lifts off the table or bends at the knee when the opposite leg is raised, it suggests tightness in the hip flexors. If the straight leg remains on the table but is elevated, it suggests weakness in the hip flexors.

The Thomas Test can provide valuable information about the patient's hip and lower back function, and can help guide treatment decisions. If tightness in the hip flexors is identified, stretching exercises can be prescribed to improve flexibility and reduce pain. If weakness in the hip flexors is identified, strengthening exercises may be recommended to improve muscle function and reduce the risk of injury.

It is important to note that the Thomas Test should always be performed by a qualified healthcare professional, as improper technique or interpretation of results can lead to inaccurate diagnoses or inappropriate treatment. Additionally, the test should be used in conjunction with other diagnostic tools and assessments to ensure a comprehensive evaluation of the patient's condition.

In conclusion, the Thomas Test is a valuable tool for assessing the length and flexibility of the hip flexor muscles, including the psoas muscle. By providing insight into the patient's hip and lower back function, this test can help guide treatment decisions and improve outcomes for individuals with muscle imbalances or related conditions. If you are experiencing pain or discomfort in your hip or lower back, speak with your healthcare provider about whether the Thomas Test may be an appropriate diagnostic tool for your condition.

How to Stretch the Psoas Muscles

About Dr Elizabeth Wagner PT PhD