The psoas muscle should be tested for strength with the patient supine and the hip flexed approximately 30 degrees. Examiner resists against the anterior distal femur. There may be pain in psoas tendinitis or iliopectineal bursitis and weakness with pain in avulsion fracture of the lesser trochanter, psoas rupture or upper femur metastasis. Weakness without pain may incicate L1, L2 or L3 nerve root involvement. Cyrias12 mentions that chronic psoas strain may remain for years unless treated by friction massage below the inguinal ligament, medial to the sartorius.
Patients who do sit-ups from a supine to a full-flexed position are really strengthening their iliopsoas rather than their abdominal muscles. They are creating an increased lordosis during the sit-up. The crunch method of sit-ups with the spine flat on the ground and the knees flexed over a chair is the recommended method.
During the first 30 degrees of hip flexion there is little or no activity in the iliopsoas. After that range there is greatly increased activity.9
References- Michele AA: Iliopsoas. Springfield, Ill: Charles C. Thomas, 1962.
- Bachrach RM, Micelotta J, Winuk C: The relationship of low back pain to psoas insufficiency. J Orth Med. 13:34-40, 1991.
- Sypher F: Pain in the back: A general theory. J Intl Coll Surg., 333:718-728, 1960.
- Goodheart GJ: Collected Published Articles and Reprints. Montpelier, Williams County Publishing, 1969.
- Nachemson AL: Electromyographic studies on the vertebral portion of the psoas muscle. Acta Orthopaedica Scandinavica, 37:177-190, 1966.
- Cailliet R: Low Back Pain Syndrome. Philadelphia: FA Davis, 84: 1962.
- Durianova J: Psoas spasm in the clinical picture of low back pain. In: Lewit K, et al., eds. Rehabilitacia, Proceedings of the IVth Congress Prague: International Federation of Manual Medicine, 1975.
- Travell JG, Daita B: Myofascial pain syndromes: The Travell trigger-point tapes, myofascial pain syndromes of the low back and hip. Baltimore, Maryland, Williams & Wikins, Electronic Media.
- Basmajian JV, Deluca CJ: Muscles Alive: Their Function Revealed by Electromyography. ed 5. Baltimore: Williams & Wilkins, 311: 1985.
- Fox EA: Let us consider the importance of psoas muscle contraction. J Natl Chiro Assoc., 26(7):69-74, 1956.
- Randeria JP: The role of the psoas muscles in low back pathology. Manuelle Medizin, 4:85-87, 1974.
- Cyriax J: Textbook of Orthopaedic Medicine: Diagnosis of Soft Tissue Lesions. ed. 8. London: Bailliere Tindall, 1:389, 1982.
Warren Hammer, M.S., D.C., D.A.B.C.O.Norwalk, ConnecticutEditor's Note:
Specialist Hammer will conduct his next soft tissue seminar on March 14-15, 1992 in Las Vegas, Nevada. You may call 1-800-327-2289 to register.
Specialist Hammer's new book, Functional Soft Tissue Examination and Treatment by Manual Methods: Extremities, is now available. Please see the Preferred Reading and Viewing list on page xx, Part #T126 to order your copy.