FABER Test: Understanding a Positive Result for Hip and SI Joint Issues

What is a positive Faber test?

A positive FABER test, an orthopedic assessment, indicates the presence of pain or restricted range of motion in the hip or sacroiliac (SI) joint when the hip is placed in a specific position of flexion, abduction, and external rotation, often suggesting underlying musculoskeletal pathology.

Understanding the FABER Test Acronym

The FABER test is an acronym that precisely describes the three movements the hip joint undergoes during the assessment:

• Flexion: The hip is bent, bringing the knee towards the chest.
• ABduction: The leg is moved away from the midline of the body.
• External Rotation: The leg is rotated outward, so the knee points away from the body while the foot is closer to the midline.

Also known as Patrick's test, this maneuver is a common orthopedic assessment used by healthcare professionals, physical therapists, and kinesiologists to evaluate the hip joint and the sacroiliac joint for various conditions.

How the FABER Test is Performed

The FABER test is typically performed with the individual lying flat on their back (supine position) on an examination table.

• Patient Positioning: The individual lies supine with both legs extended.
• Examiner Action:
  1. The examiner passively flexes the hip and knee of the test leg.
  2. The ankle of the test leg is then placed on the opposite thigh, just above the kneecap (patella). This position places the hip in flexion, abduction, and external rotation.
  3. The examiner gently stabilizes the opposite anterior superior iliac spine (ASIS) with one hand to prevent pelvic rotation.
  4. With the other hand, the examiner applies gentle, sustained pressure to the medial aspect of the test knee, attempting to lower the knee towards the examination table.

The goal is to assess the range of motion and provoke any pain or discomfort in the hip or sacroiliac region.

Interpreting a Positive FABER Test

A "positive" FABER test is indicated by two primary findings: pain or restricted range of motion.

• Key Indicators:

  • Pain: The primary indicator of a positive test is the reproduction of pain. The location of the pain helps to pinpoint the potential source:
    • Anterior hip/groin pain: Often suggests pathology within the hip joint itself, such as hip osteoarthritis, femoroacetabular impingement (FAI), iliopsoas muscle spasm or tendinopathy, or capsular restrictions.
    • Posterior hip/sacroiliac joint pain: Suggests dysfunction or pathology of the sacroiliac joint, such as sacroiliac joint inflammation, sprain, or instability.
  • Restricted Range of Motion: If the test leg's knee remains significantly elevated from the table compared to the opposite side, or if the individual cannot achieve the full FABER position without compensation, it indicates a restriction in hip mobility. This restriction could be due to tight hip adductors, hip capsule tightness, or bony impingement.

• Potential Implications: A positive FABER test is a provocative test, meaning it attempts to reproduce symptoms to identify a problem. It is not diagnostic on its own but suggests the need for further evaluation. Common conditions that may elicit a positive FABER test include:

  • Hip Osteoarthritis
  • Femoroacetabular Impingement (FAI)
  • Labral Tears of the Hip
  • Iliopsoas Tendinopathy or Bursitis
  • Sacroiliac Joint Dysfunction (e.g., sacroiliitis)
  • Hip Adductor Muscle Strain or Tightness

Clinical Relevance and Limitations

The FABER test is a valuable screening tool for assessing hip and sacroiliac joint function because it combines multiple movements that stress these structures. It is particularly useful for differentiating between intra-articular (within the joint) hip issues and extra-articular (outside the joint) or sacroiliac joint problems.

However, it is crucial to understand that:

• It is not a standalone diagnostic test. A positive FABER test should always be interpreted in conjunction with a thorough patient history, other orthopedic special tests, and potentially imaging studies (e.g., X-rays, MRI) to arrive at a definitive diagnosis.
• Specificity and Sensitivity: While helpful, the test has varying levels of specificity and sensitivity for different conditions. For instance, it's highly sensitive for hip intra-articular pathology but less specific for differentiating between various hip pathologies without additional testing.
• Individual Variation: Normal hip mobility varies among individuals. A comparison to the unaffected side is often helpful.

Conclusion

The FABER test is a fundamental orthopedic assessment used to evaluate the hip and sacroiliac joints. A "positive" result, characterized by pain or restricted motion during the specific flexion, abduction, and external rotation maneuver, serves as a critical indicator for potential underlying pathologies. For fitness professionals, understanding this test helps in recognizing potential issues in clients, guiding referrals to appropriate healthcare providers, and informing exercise modifications to ensure safety and promote recovery.