Sartorius Muscle Pain: Everything You Need to Know

The sartorius muscle is a long muscle that runs from the front of the thigh to the knee and helps to rotate the thigh and flex the knee. Sartorius muscle pain can cause swelling, pain, and weakness in the muscle and limit mobility.

This article discusses the anatomy and function of the sartorius muscle, as well as what might cause pain in the muscle and what to do about it.

Symptoms of Sartorius Muscle Injury

Sartorius muscle injuries may cause symptoms in the upper part of your leg that include:

• Pain
• Tenderness
• Swelling
• Muscle weakness
• Stiffness

Anatomy

The sartorius muscle starts at the front part of your pelvis called the anterior superior iliac spine (ASIS). From there, the muscle courses down across the front of your thigh.

It then crosses your inner knee, inserting in the front of your shin bone at a place called the pes anserine. The pes anserine is called the goosefoot and is the insertion point for the sartorius, gracilis muscle, and the semi-tendinosis muscle of the hamstring.

The muscle is very long, and it can be palpated or touched in the front part of your hip near your pelvic bone. Simply place your hand on the bony part of your pelvis in front of your hip. Then, flex your thigh up and rotate it outward; the muscle that protrudes is the sartorius.

The sartorius is also known as the "tailor's muscle." This is because it helps to flex and rotate your hip and flex your knee; if you were to sit with one leg crossed over the other, with the ankle on top of the other knee, then the sartorius muscle would be working. This position was often adopted by tailors when sewing seams by hand.

Function

Since the sartorius muscle is very long and crosses two joints (the hip and the knee) it serves many functions for your body and lower extremities, including:

• Flexion of your hip: This means that it bends your hip up as if you were marching. Other muscles, such as your psoas muscle, also flex your hip up.
• External rotation of your hip: The sartorius has a line of pull across the front of your thigh, and this line of pull helps to rotate your hip outwards. If you are standing and lift your foot up and in to look at the bottom of your shoe, your sartorius would be active lifting and externally rotating your hip.
• Flexion of your knee: The sartorius crosses to the inner side of your knee and attaches to the front of your shin bone. When the muscle contracts, it bends your knee. Your hamstrings also bend your knee, so the sartorius is most active with knee bending while your hip is flexed and rotated.

The sartorius muscle is innervated (supplied by) the femoral nerve. This nerve arises from your low back at lumbar levels two, three, and four.

The sartorius muscle receives blood supply from various arteries that penetrate the muscle at irregular intervals. These blood vessels include the superficial circumflex iliac, the lateral femoral, and the deep femoral arteries of your thigh.

Associated Conditions

Your sartorius muscles may be involved in several different conditions that may limit your functional mobility.

These may include:

• Sartorius muscle strain
• Tear of the sartorius muscle
• Pes anserine tendonitis
• Sartorius paresis or paralysis due to a pinched nerve injury in your lumbar spine

If you have leg pain or weakness, visit your healthcare provider right away to get an accurate diagnosis and to start the proper treatment for your condition.

Rehabilitation

If you have an injury to your sartorius, you may benefit from working with a physical therapist (PT) during rehabilitation. The treatments you receive from your PT may vary based on your specific injury.

These injuries include:

• Sartorius tendonitis: Tendonitis typically causes pain and limited mobility of the muscle. You may feel pain in the front of your hip while flexing and rotating it during walking. Therapy may help decrease the inflammation of the muscle and improve its ability to contract properly to help you regain mobility.
• Sartorius tear: A tear to the sartorius may require a significant period of immobility and rest to allow for the muscle to heal. Once healing has taken place, your PT may work with you to improve scar tissue mobility, improve sartorius muscle flexibility, and improve the strength of the muscle.
• Pes anserine tendonitis: The hallmark of this condition is pain in the medial and front aspect of your upper shin bone just below your knee. Therapy can help you decrease pain and inflammation, improve sartorius flexibility, and improve strength.
• Weakness due to nerve injury: Nerve compression in the lower back due to herniated disc or spinal foraminal stenosis can produce pain and weakness in the front of your thigh, affecting your sartorius. Treatment may include exercises to relieve nerve compression and to correct your posture.

An injury to the sartorius muscle usually occurs in conjunction with an injury to another thigh muscle, like the psoas or the quadriceps. These muscles all work together to move your thigh and knee, and therefore an injury to one muscle may also affect the others.

Your healthcare provider and physical therapist can help you understand your specific prognosis when it comes to an injury to your sartorius.

Exercises

Exercises to strengthen the sartorius muscle include the following. Aim to repeat each exercise 10 to 15 times (on both sides if the exercise is done one leg at a time).

Squats

1. Stand with your feet slightly wider than your hip width
2. Keep your spine straight and your shoulders down
3. Imagine your heels are glued to the floor
4. Actively press your knees outward so they are pointing in the direction of the second toe
5. Engage your core to keep your lower back flat 
6. Lower your hips deeply, but keep your knees at a right angle
7. When you stand up, press your feet into the earth and straighten your legs

Lunges

1. From a standing position, take a step forward with one leg, lowering your body until both knees are bent at a 90-degree angle.
2. Push off with the front foot to return to the starting position
3. Repeat with the other leg.

Lateral Step- Ups

1. Stand to the side of a sturdy box or bench.
2. Bend your knee and hip to step on the bench.
3. Straighten the leg on the bench while lifting the other leg up (keeping it straight).
4. Repeat on the other side.
   

Clamshells

1. Lie on your side, your bottom arm extended upward to support your head and neck.
2. Flex your hips and knees, so your thighs are positioned at a 90-degree angle to your torso and your knees are also bent at roughly 90 degrees.
3. Make sure your shoulders and hips and knees are stacked, your body is perpendicular to the floor.
4. Keeping your big toes touching, tighten your core, and externally rotate your top hip so your knees open, as though you were a clam opening up.
5. Rotate as far as you comfortably can with good form, then reverse the movement, internally rotating your hip back to its starting position.
   

Summary

The sartorius, or tailor's muscle, is the longest muscle in your body. It runs from the pelvis to the knee and helps you flex and rotate your hip and flex your knee. Sartorius muscle pain can cause pain, weakness, swelling, and stiffness in the muscle. Physical therapy as well as specific exercises can help relieve the symptoms and restore function.