Quadratus Femoris: Origin, Insertion, Nerve & Hip Impingement

The Quadratus Femoris is a flat, rectangular muscle located in the deep gluteal region. As its name suggests (Quadratus = square), it is short, thick, and four-sided. It is the most inferior of the deep external rotators, bridging the gap between the pelvis and the femur.

[Image of Gluteus Maximus muscle anatomy]

Quick Anatomy Snapshot

Origin (Proximal)	Lateral border of the Ischial Tuberosity (Sit bone).
Insertion (Distal)	Quadrate Tubercle on the Intertrochanteric Crest of the Femur.
Nerve Supply	Nerve to Quadratus Femoris (L5, S1).
Blood Supply	Medial Circumflex Femoral Artery and Inferior Gluteal Artery.
Primary Actions	External Rotation: Strong lateral rotator of the thigh. Adduction: Assists in adduction of the thigh. Stabilization: Holds the femoral head in the acetabulum.

Deep Dive: The Square Stabilizer

The Quadratus Femoris is located immediately below the Gemellus Inferior and above the Adductor Magnus. Its parallel fiber arrangement gives it significant strength for its size.

1. The Sciatic Relationship

The massive Sciatic Nerve passes directly over (posterior to) the surface of the Quadratus Femoris as it travels down the leg. This makes the muscle a potential (though less common than Piriformis) site for nerve compression.

2. Ischiofemoral Space

The muscle fills the space between the Ischium (pelvis) and the Lesser Trochanter (femur). This anatomical gap is known as the Ischiofemoral Space. Narrowing of this space can crush the Quadratus Femoris muscle, causing pain.

Physio Corner: Clinical Relevance

💪 Functional Fact: While walking, the Quadratus Femoris controls the rotation of the leg during the stance phase and fine-tunes the position of the femur to keep the ball centered in the socket.

Palpation

Palpation is difficult due to the muscle's depth (under Gluteus Maximus).
Technique: Locate the Ischial Tuberosity and the Greater Trochanter. The Quadratus Femoris lies horizontally between these two landmarks. Deep pressure here in a prone patient may reproduce buttock pain associated with Ischiofemoral Impingement.

⚠️ Clinical Pathology: Ischiofemoral Impingement (IFI)
This condition presents as deep buttock or groin pain. It occurs when the space between the Ischium and Lesser Trochanter narrows (often due to hip instability or structural abnormalities), crushing the Quadratus Femoris muscle.
Quadratus Femoris Sign: MRI shows edema or atrophy specifically in this muscle.

Manual Muscle Testing (MMT)

We test the external rotator group as a whole.

Testing Tip: Testing in the prone position (hip extension) recruits the Quadratus Femoris effectively, as it is a strong rotator in neutral/extension.

Step-by-Step Procedure (Oxford Scale)

Grade	Patient Action & Resistance
Grade 3, 4, 5 (Against Gravity)	Position: Prone (face down). Knee flexed to 90°. Action: Patient moves the foot medially (which rotates the hip externally). Resistance: Applied at the medial ankle, pushing the foot laterally (into internal rotation). Grade 3: Full range against gravity. Grade 4/5: Holds against strong resistance.
Grade 2 (Gravity Eliminated)	Position: Supine. Leg extended and internally rotated. Action: Patient rolls the leg outward (toes point out). Result: Full range of external rotation.
Grade 0, 1 (Palpation)	Action: Deep palpation between Ischium and Trochanter. Cue: "Try to turn your thigh out." Grade 1: Deep tension felt. Grade 0: No activity.

Frequently Asked Questions

Which nerve supplies Quadratus Femoris?

It has its own named nerve: The Nerve to Quadratus Femoris (L5, S1). This nerve also supplies the Gemellus Inferior muscle.

Is it an adductor?

Yes, it assists in Adduction because its line of pull is medial to the hip joint axis. However, its primary and most powerful action is External Rotation.

What sits above and below it?

Superior: Gemellus Inferior.
Inferior: Adductor Magnus (upper fibers).
Posterior (Superficial): Sciatic Nerve and Gluteus Maximus.

Test Your Knowledge: Quadratus Femoris Quiz

1. What is the shape of the Quadratus Femoris?

2. Where does the Quadratus Femoris insert?

3. Which nerve supplies this muscle?

4. What is the primary action?

5. Which pathology involves narrowing of the space between the Ischium and Femur?

6. Where does the Quadratus Femoris originate?

7. Which large nerve runs superficial (posterior) to this muscle?

8. Besides rotation, what is a secondary action?

9. The Quadratus Femoris is located immediately inferior to the:

10. True or False: The nerve to Quadratus Femoris also supplies the Gemellus Inferior.

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2018). Clinically Oriented Anatomy. 8th ed. Philadelphia: Wolters Kluwer.
• Standring, S. (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st ed. Elsevier.
• Travell, J. G., & Simons, D. G. (1999). Myofascial Pain and Dysfunction: The Trigger Point Manual. 2nd ed. Williams & Wilkins.