Related Experiment Video
Updated: Jul 16, 2026

In Vivo Canine Muscle Function Assay
Published on: April 5, 2011
The piriformis muscle syndrome: a simple diagnostic maneuver
1Department of Neurosurgery, University of Illinois, College of Medicine, Chicago.
Abstract:
Current maneuvers to diagnose the piriformis syndrome are less than ideal. Freiberg's maneuver of forceful internal rotation of the extended thigh elicits buttock pain by stretching the piriformis muscle, and Pace's maneuver elicits pain by having the patient abduct the legs in the seated position, which causes a contraction of the piriformis muscle. This report describes a maneuver performed by the patient lying with the painful side up, the painful leg flexed, and the knee resting on the table. Buttock pain is produced when the patient lifts and holds the knee several inches off the table. The maneuver produced deep buttock pain in three patients with piriformis syndrome. In 100 consecutive patients with surgically documented herniated lumbar discs, the maneuver often produced lumbar and leg pain but not deep buttock pain. In 27 patients with primary hip abnormalities, pain was often produced in the trochanteric area but not in the buttock. The maneuver described in this report was helpful in diagnosing the piriformis syndrome. It relies on contraction of the muscle, rather than stretching, which the author believes better reproduces the actual syndrome.
Related Concept Videos
Muscles that Move the Thigh
Three other significant muscles are the gluteus maximus, gluteus medius, and gluteus minimus. The gluteus maximus originates from the posterior surface of the ilium, sacrum, and coccyx, and the thoracolumbar fascia...
Muscles that Move the Leg
Anterior Compartment
The quadriceps femoris, the most visible muscle of the anterior compartment, is integral for leg extension and thigh flexion. It is formed by merging four distinct muscles — the vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris. The quadriceps tendon, a shared tendon of the four quadriceps muscles, is affixed to...
Muscles of the Leg that Move the Foot and Toes
Anterior Compartment
The anterior compartment includes muscles that contribute to the dorsiflexion of the foot. This compartment houses the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles.
Reflex Activity
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
Appendicitis-I: Introduction
Etiology: Appendicitis can arise from various causes, primarily rooted in the obstruction of the appendix lumen. Factors contributing to this obstruction include fecal accumulation, lymphoid hyperplasia and, in...

