Femoroacetabular impingement

Femoroacetabular impingement (FAI) is a condition that affects the hip joint. It causes pain, limitation of movement, and ultimately, joint damage. Fortunately, physical therapy exercises can strengthen the muscles that support your hip joint. They can help reduce hip pain and improve your range of motion.

In this guide on femoroacetabular impingement syndrome, we discuss the different types of FAI. We also explain the causes, symptoms, and treatment of femoroacetabular impingement. Last but not least, we introduce you to some exercises that can help you reduce your symptoms.

Juhi Modi Medical Writer


What is Femoroacetabular Impingement (FAI) Syndrome?
Types of FAI
Causes of Femoroacetabular Impingement
Symptoms of Femoroacetabular Impingement
Diagnosis of Femoroacetabular Impingement
Treatment for FAI Syndrome
Other Treatment Options for Femoroacetabular Impingement
When to see a doctor
Healing from Hip Impingement

Do you find your hip joint is painful and stiff? Is it difficult for you to sit for very long or walk without a limp? Does the pain in your hip keep you up at night? You could be suffering from a condition called femoroacetabular impingement (FAI). Your symptoms may be making it impossible to do the things you love, such as dancing, running, hiking, or skiing. Thankfully, femoroacetabular impingement doesn’t have to leave you sitting on the sidelines. You can get back in the game with the right treatment and exercise.

FAI occurs due to abnormal development of the hip bones during your growing years. Over time, the hip joint becomes damaged, leading to hip pain. Active people often begin to experience the symptoms of femoroacetabular impingement earlier in life. This is because they use the hip joint more intensely during athletic activities.

If you’ve been diagnosed with FAI, do not despair. People with femoroacetabular impingement can live long, active lives without major problems. The hip pain and other symptoms can be managed with physical therapy exercises at home. The Injurymap app makes these exercises easily accessible to you. It also demonstrates the correct way to do the exercises.

In this comprehensive guide we give you all the information you need about femoroacetabular impingement. Remember, the guide is for information only. It is not a replacement for formal medical care. Specifically, you should seek the opinion of a healthcare provider if your symptoms do not improve with home rehab exercises.

Looking for a solution to hip pain from femoroacetabular impingement? Try the Injurymap exercise app now.

What is Femoroacetabular Impingement (FAI) Syndrome?

Femoroacetabular impingement is a condition that affects your hip joint. The hip joint is a ball-and-socket joint. The ball is the upper end of the femur (the large bone in your thigh). It fits into a cavity or socket in the pelvic bone called the acetabulum. In a healthy hip, the ball fits snugly into the socket. A strong cartilage called the labrum lines the acetabulum and creates a tight seal. This helps maintain a smooth surface between the bones and prevents friction. It also provides stability to the hip joint.1

Hip Anatomy

In people with femoroacetabular impingement, bone spurs develop around the head of the femur (the ball) and/or along the acetabulum (the socket). Bone spurs are abnormal bony projections that form at the edges of a bone.2 When these extra bone growths develop in one or both of the hip bones, they encroach or impinge upon the joint. Hence the name femoroacetabular impingement. The bone spurs in the hip create abnormal contact between the bones. They give the joint an irregular shape. This creates friction when the bones move, leading to symptoms such as hip pain. Over time, the continued friction can lead to limitation of movement and damage to the joint.

Types of FAI

There are three types of femoroacetabular impingement, depending on the location of the bone spurs.

Pincer: In this type of FAI, bone spurs grow on the rim of the acetabulum. These abnormal bumps can crush the labrum, and collide with the cartilage of the head of thefemur,, leading to joint damage.


Cam: This type of hip impingement occurs when the neck of the femur, which is usually smooth and concave, develops bone spurs. The misshapen femoral neck grinds against the labrum (cartilage) and damages it.


Combined: This is a combination FAI in which bone spurs are present on both the femur and the acetabulum.


Causes of Femoroacetabular Impingement

FAI or hip impingement is a structural abnormality. It is caused due to the irregular shape of the femur (thigh bone) or acetabulum (hip socket) from the formation of bone spurs.

Some people with femoroacetabular impingement are born with an abnormal joint. In other cases, the hip joint develops bone spurs during the growing years.3 You cannot prevent the development of hip impingement. But it is possible to control the symptoms and lead an active and pain-free life.

Symptoms of Femoroacetabular Impingement

The two main symptoms of hip impingement are pain and stiffness. Some people may limp or be unable to bend the hip beyond a right angle.3 The pain from hip impingement can be a sharp, stabbing pain or a dull ache. It is usually present in the groin area. Squatting, turning, and twisting typically make the pain worse. The symptoms may also be worse after activities such as running, jumping, or sitting for an extended period.3

Some people with FAI do not experience any symptoms and are unaware that they have the condition. Symptoms usually develop when the condition progresses and there is damage to the labrum or the hip joint cartilage..

Athletes who play sports such as football, baseball, tennis, and golf often perform repetitive movements of the hip. They also tend to move the legs beyond a normal range of motion.3 For this reason, the symptoms of hip impingement can begin earlier in dancers and athletes compared to less active people. It is worth remembering that exercise or dance does not cause femoroacetabular impingement. The condition is a developmental structural abnormality that cannot be prevented.

Diagnosis of Femoroacetabular Impingement

One of the tests doctors use to diagnose FAI is called the impingement test. It consists of bringing the knee toward the chest and rotating it inward in the direction of the shoulder. If this movement recreates your hip pain, it indicates you have femoroacetabular impingement.

Impingement Test

In another test for FAI, a local anesthetic (numbing medicine) is injected into the hip joint. If the medication gives you temporary pain relief, it points towards FAI as the source of your pain, in the absence of other causes of hip joint pain1

Your doctor may order an imaging test such as an X-ray, MRI, or CT scan to see if there is any damage to the hip joint cartilage.1

Treatment for FAI Syndrome

Physical therapy is key in treating femoroacetabular impingement. Rehab exercises can help strengthen the muscles that support the hip joint. They also improve your hip range of motion. Stretching these muscles relieves the stress on the damaged cartilage. Here are three exercises that can help you control your hip pain from femoroacetabular impingement.

Exercises for FAI Syndrome

  1. Hip bend I
    5 reps x 3 sets

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    • Sit on a chair with your legs bent.
    • Keep your back straight by tightening your stomach and back muscles.
    • Keep one leg bent 90 degrees in the knee and lift it up into the air so that it is completely free of the chair.
    • Keep the other leg relaxed on the floor and avoid using it to push away from the floor.
    • Push down on the thigh with as much force as possible while being able to hold the position for 10 seconds.
    • Perform 3 sets of 5 repetitions in each direction.
  2. Outer hip stretch
    30 sec. x 3 sets

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    • Stand with an arm's length to a wall.
    • Support yourself against the wall at shoulder height.
    • Stand on the leg that is closest to the wall.
    • Rotate your toes a little away from the wall.
    • Slide the pelvis forward and move it towards the wall.
    • You should feel the stretch along the outside of your hip.
    • Hold the stretch for 30 seconds and perform 3 repetitions on each side.
  3. Lunges I
    8 reps x 3 sets

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    • Stand with your weight evenly distributed between both legs.
    • Take a long step forward with one leg.
    • Bend your knee and ankle while moving forward, then push back to the initial position.
    • Make sure the knee is moving straight forward in the direction of your toes.
    • Perform 3 sets of 8 repetitions with each leg.
    • It should feel similar with both legs.

Other Treatment Options for Femoroacetabular Impingement

Activity Changes: It may be possible to reduce your hip pain by avoiding certain types of activities in your daily routine. For example, you could avoid squatting if it causes symptoms or makes your pain worse.

Pain Medication: NSAIDS (nonsteroidal anti-inflammatory drugs) such as ibuprofen can provide short-term relief of pain from hip impingement.

Surgery: Doctors sometimes recommend surgery in people who have damaged hip joint cartilage due to FAI. Surgery may also be recommended if your pain does not get better with medications and exercise. During the surgery, the surgeon will trim down the bumps in the bone to reduce friction and relieve symptoms.1


Risk of Osteoarthritis and Labral Tear

Over time, the friction caused by bone spurs in the hip can lead to a breakdown of the labrum and of the cartilage. The labrum is a ring of fibrocartilage that surrounds the hip socket. The cartilage is a protective structure that cushions the bones and prevents friction. If the labrum or cartilage becomes torn or damaged, it can lead to painful and debilitating osteoarthritis. The longer you leave painful symptoms of femoroacetabular impingement untreated, the more damage it can cause in your hip.1

When to see a doctor

Most people can manage femoroacetabular impingement with home remedies. All you need to do is avoid the activities that cause pain and use occasional pain pills. Once the hip has had a chance to rest and your pain has settled down, you can begin working on strengthening and stretching the hip muscles. However, if your symptoms do not go away with home physical therapy, you should see a doctor and find out the exact cause of your hip pain.

Healing from Hip Impingement

If you have femoroacetabular impingement, it is not the end of an active lifestyle for you. And you don’t have to live with constant hip pain and stiffness. It is possible to restore your hip to good health with the proper training. Exercises can help reduce your pain by strengthening the muscles that surround the hip joint. This includes large muscles such as the hamstrings, quadriceps, glutes, hip adductors, and hip flexors. Performing stretches can also provide you with good pain relief. But it’s important to do the exercises and stretches correctly.

The Injurymap app shows you the correct way to perform dozens of different hip strengthening exercises. You can do these exercises in the comfort of your home with little to no equipment. As your muscles become stronger and you become more flexible, your symptoms of femoroacetabular impingement should be reduced.

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About the author

Juhi Modi has two decades of experience as a medical writer with varied interests and an enduring passion for health, biology, and science. She uses her educational background in medicine to write science-backed articles for clients around the world.


  1. https://orthoinfo.aaos.org/en/diseases--conditions/femoroacetabular-impingement/ 

  2. https://www.mayoclinic.org/diseases-conditions/bone-spurs/symptoms-causes/syc-20370212 

  3. https://www.ortho.wustl.edu/content/Patient-Care/3206/Services/Hip-Knee/Adult-Reconstruction-and-Hip-Preservation-Overview/Hip-Impingement.aspx