What is Ober’s Test?
Ober’s test is used to evaluate the tightness in the Tensor Fascia Latae muscle (TFL) and Iliotibial band (ITB). Let us now study the clinically relevant anatomy of both the structures, the iliotibial band and the tensor fascia latae muscle.
Anatomy of Tensor Fascia Latae Muscle And Iliotibial band
The Iliotibial band is a continuation of the tensor fascia latae muscle. It runs along the lateral aspect of the thigh.
- The Tensor Fascia Latae originates from the anterior superior iliac spine’s outer surface, the outer lip of the anterior iliac crest and deep surface of the fascia latae.
- The Iliotibial Band (ITB) is a continuation or longitudinal reinforcement of the tensor fascia latae muscle in the thigh.
- The Tensor Fascia Latae inserted or blends into the iliotibial band.
- The Iliotibial Band inserts to Gerdy’s tubercle of the tibia.
- The Tensor Fascia Latae muscle assist in flexion, medial rotation and abduction of the hip joint.
- The Iliotibial band extends, abducts and laterally rotates the hip joint.
The connection between TFL and IT Band
The Tensor Fascia Latae runs inferiorly and blends into the Iliotibial band (ITB). A tendon is present in every muscle at both the ends which joins them from one bone to another bone. The TFL is just one of the few exceptions, as it blends into the IT band rather than forming its tendon.
The Iliotibial band is a non-contractile portion of tissue. This implies it can not become tight of its own accord. Here, the TFL is inserting or blending into the IT Band. Now when the tensor fascia latae becomes tight, it will pull on the iliotibial band and hence tighten it.
Ober’s test is used to test the tightness in IT band and TFL. Frank Ober introduced this test to detect tightness in TFL and IT band’s in an article labelled ‘Back Strain and Sciatica’. In that article, he discussed the connection of tightened TFL and ITB to low backache in May 1935.
Procedure For Performing The Ober’s Test
- The patient should lie in a side-lying position with the affected side up.
- The patient’s lower leg (bottom hip and knee) should be flexed for stability as well as to flatten the lumbar curve.
- The therapist should stand behind the patient and stabilize the upper iliac crest (pelvis/greater trochanter) with one hand to prevent movement in any direction.
- With the other hand, grasp the distal end of the patient’s affected leg and flex the leg to a right angle (90°) at the knee.
- The therapist then gradually lift the patient’s upper leg (extend and abducts the hip joint) with the knee flexed at 90°.
- After that, the therapist then slowly lower the leg towards the table.
- Ensure that the patient’s hip and pelvis should be stabilized. The hip should be slightly extended, and the hip should not internally rotate and flex during the test. If the examiner could not stabilize the hip during the trial, the leg will drop down, giving a false negative result.
If the TFL and ITB are tight, the leg would remain in an abducted position and does not fall to the table, and the patient would experience lateral knee pain. Therefore, this indicates the positive Ober’s test.
If the TFL and ITB is normal, the leg will slowly drop down towards the table, and the patient won’t experience any pain. Therefore, this indicates the negative Ober’s test.