Straight Leg Raise with Hip Impingement: Clinical Presentation
The straight leg raise (SLR) test is not a primary diagnostic maneuver for hip impingement and typically does not reproduce the characteristic symptoms of femoroacetabular impingement (FAI).
Key Clinical Distinction
Hip impingement is best assessed through flexion, adduction, and internal rotation of the hip (the anterior impingement test), not through straight leg raising 1, 2. The SLR test primarily evaluates hamstring flexibility and neurogenic pain patterns, not intra-articular hip pathology 3, 4.
Expected Findings During SLR in Hip Impingement Patients
Limited Range of Motion
- Hip flexion is typically restricted to approximately 97 degrees in patients with symptomatic FAI 2
- Internal rotation in flexion is markedly limited to an average of only 9 degrees 2
- The SLR may demonstrate reduced hip flexion range compared to unaffected individuals, but this reflects overall hip stiffness rather than impingement-specific pathology 2
Pain Characteristics (When Present)
- If pain occurs during SLR in a patient with hip impingement, it is predominantly located in the groin (83% of cases) 2
- Pain onset during SLR is typically activity-related and insidious rather than acute 2
- The pain pattern differs from the sharp, catching sensation characteristic of the anterior impingement test 1
Critical Clinical Pitfall
Do not rely on the SLR test to diagnose or exclude hip impingement. The anterior impingement test (flexion, adduction, internal rotation) reproduces pain in 88% of hips with FAI, making it far superior for clinical diagnosis 2. The SLR test evaluates different biomechanical stressors—primarily posterior hip tissue extensibility and hamstring flexibility—rather than the anterosuperior acetabular rim contact that defines impingement 5, 3.
Biomechanical Context
- Hip impingement involves pressure of the femoral head on the anterosuperior rim of the acetabulum during hip flexion 5
- This pathomechanics occurs with combined flexion, adduction, and internal rotation, not with the extended knee position of SLR 5
- The SLR primarily loads posterior hip structures and creates passive stretch rather than the anterior impingement contact 3
Recommended Clinical Approach
Use the anterior impingement test as your primary physical examination maneuver for suspected hip impingement 1, 2. Perform this by bringing the hip into 90 degrees of flexion, then adding adduction and internal rotation while the patient is supine 1. Pain reproduction with this maneuver, combined with groin-predominant symptoms and limited internal rotation, strongly suggests FAI 2.