Hip impingement, or femoroacetabular impingement (FAI), is a hip condition in which an unusually shaped ball or socket pinches during movement, causing deep groin pain with squatting, sitting and twisting. Most people improve with targeted physiotherapy and activity changes. For selected patients whose pain persists, keyhole hip surgery (hip arthroscopy) gives a further, modest benefit, according to three randomised trials.

This guide explains what FAI is, how to recognise it, how it is diagnosed, and what the best research says about physiotherapy and surgery, so you can make an informed decision with your doctor.

Key takeaways

An odd-shaped hip on X-ray is very common and often painless. FAI syndrome needs symptoms, examination signs and imaging together.
Typical symptoms are deep groin pain with bending, squatting, long sitting and twisting, often with stiffness or clicking.
Physiotherapy-led care is the right first step for most people.
In three randomised trials (UK, England and Australia), hip arthroscopy improved symptoms more than physiotherapy at 8–12 months, but both groups got better.
Most athletes return to sport after arthroscopy; about three in four return to their previous level, typically around 7 months after surgery.

What is hip impingement (femoroacetabular impingement)?

Your hip is a ball-and-socket joint. The ball is the femoral head, at the top of the thigh bone. The socket is the acetabulum, part of the pelvis. A rim of cartilage called the labrum seals the socket.

In FAI, the ball or socket has extra bone. When you bend the hip deeply, the bones meet too early and pinch the labrum and joint cartilage. Over time this can cause labral tears and cartilage wear.

In 2016, an international panel of experts published the Warwick Agreement in the British Journal of Sports Medicine. It defines FAI syndrome as a motion-related hip disorder with a triad of symptoms, clinical signs and imaging findings. All three must be present.

Types of FAI

Type	What is different	Who it commonly affects
Cam	Extra bone at the femoral head-neck junction makes the ball less round	Young, active men; athletes who played high-impact sport during adolescence
Pincer	The socket covers too much of the ball, or is angled backwards	More often women; active middle-aged adults
Mixed	Both cam and pincer features	Common; many patients have some of each

Hip shape is not the same as hip disease

Impingement-type hip shape is very common in people with no pain. A systematic review by Frank and colleagues (Arthroscopy, 2015) found cam shape in about 37% of people without symptoms, rising to about 55% in athletes. Labral tears were also seen on MRI in many pain-free people.

The English FAIT trial authors estimate that fewer than one in four people with FAI shape go on to develop pain or arthritis. This is why a good specialist treats you, not your X-ray.

Hip impingement symptoms

Common symptoms include:

Deep groin pain at the front of the hip, sometimes felt on the outer hip or buttock
The "C-sign": cupping the side of the hip with a C-shaped hand to show where it hurts
Pain with deep bending: squatting, floor sitting, cross-legged sitting, Indian-style toilets, getting in and out of a car
Pain after sitting for long periods, especially in low chairs
Pain with twisting, pivoting and kicking in football, cricket, hockey and kabaddi
Clicking, catching or locking, which can suggest a labral tear
Stiffness, especially when turning the bent hip inwards

Symptoms usually start gradually and worsen with activity. FAI is often mistaken for a groin strain or a back problem, so many patients see several doctors before diagnosis.

FAI vs other causes of groin and hip pain

Condition	Typical age	Pain pattern	Key feature
FAI syndrome	15–45 years	Deep groin pain with bending and twisting	Positive FADIR test; cam or pincer shape on X-ray
Adductor (groin) strain	Any athlete	Inner thigh pain	Pain squeezing knees together; often a specific injury
Sports hernia (athletic groin pain)	Young athletes	Lower abdominal and groin pain	Pain with sit-ups, sprinting or coughing
Hip osteoarthritis	Usually over 50	Groin pain, morning stiffness	Joint space narrowing on X-ray
Referred pain from the lower back	Any adult	Buttock and thigh pain	Pain linked to back movement

How is FAI diagnosed?

Diagnosis combines your history, an examination and imaging. No single test is enough.

Examination

FADIR test (flexion, adduction, internal rotation): the doctor bends your hip and turns it inwards. If it does not reproduce your pain, FAI is less likely. A positive test, however, is not specific to FAI.
Range of motion: reduced inward rotation with the hip bent is common.
FABER test (flexion, abduction, external rotation): may cause groin or buttock pain.

Imaging

X-rays (a standing pelvis view and a side view of the hip) show cam or pincer shape. Doctors measure angles such as the alpha angle (cam) and the centre-edge angle (socket coverage). X-rays also rule out arthritis and hip dysplasia, which change treatment.
MRI or MR arthrogram shows labral tears and cartilage damage.
CT scan helps plan surgery in complex cases.
Diagnostic injection of local anaesthetic into the joint can confirm whether pain comes from inside the hip.

Hip impingement treatment: what are the options?

Treatment aims to reduce pain, restore function and protect the joint.

Non-surgical treatment (first line for most people)

Activity modification: avoid positions that pinch the hip, such as deep squats, very low seats and long cross-legged sitting. A cushion on low chairs and a raised toilet seat help day to day.
Physiotherapy: a personalised programme to strengthen the hip, core and gluteal muscles, improve movement control and adjust sport technique. In the UK FASHIoN trial, physiotherapy-led care involved 6–10 sessions over 12–24 weeks.
Pain relief: short courses of anti-inflammatory medicines (NSAIDs), only under medical advice.
Joint injection: an image-guided steroid injection can ease pain and help confirm the diagnosis.
Load management for athletes: cut back high-volume kicking, deep lunging and repetitive pivoting while you rebuild strength.

Surgical treatment: hip arthroscopy

Hip arthroscopy is keyhole surgery using a small camera and instruments passed through two or three small cuts. The surgeon can:

Reshape the femoral head-neck junction to remove a cam bump (femoroplasty)
Trim an over-covering socket rim (acetabuloplasty)
Repair or reconstruct a torn labrum
Treat damaged cartilage where possible

Surgery is generally considered when symptoms persist after a good trial of physiotherapy (usually at least 3 months), imaging confirms impingement, and there is no significant arthritis. Hip arthroscopy does not work well in established arthritis.

What does the evidence say? Physiotherapy vs hip arthroscopy

Three well-designed randomised trials have compared hip arthroscopy with physiotherapy for FAI syndrome. All three found that both treatments help, and surgery helps somewhat more in the short to medium term.

Trial	Patients	Main result
UK FASHIoN (Griffin, The Lancet, 2018)	348	At 12 months, hip quality-of-life score (iHOT-33, out of 100) was 58.8 after arthroscopy vs 49.7 with physiotherapy; adjusted difference 6.8 points, just above the 6.1-point threshold patients notice
FAIT, England (Palmer, BMJ, 2019)	222	At 8 months, daily-activity score (HOS ADL) was 78.4 after arthroscopy vs 69.2 with physiotherapy and activity modification
Australian FASHIoN (Hunter, BMC Musculoskeletal Disorders, 2021)	99	Hip quality of life improved 14 points more after arthroscopy at 12 months; no difference in cartilage health on specialised MRI

Two further findings help keep this in perspective:

Longer term: at about 3 years, FAIT patients who had surgery still reported better function (8.9 points on HOS ADL) and showed less cartilage damage on MRI. There was no difference in X-ray joint space, the standard marker of arthritis (Palmer, BJSM, 2025).
What part of surgery works? The international FIRST trial (American Journal of Sports Medicine, 2021) compared bone reshaping with a simple arthroscopic joint washout in 220 patients. Pain improved equally in both groups at 12 months. However, by 2 years fewer patients needed repeat surgery after bone reshaping (8 of 105 vs 19 of 104).

A smaller US military trial (Mansell, 2018) found no difference between surgery and physical therapy at 2 years, although many patients switched treatment groups.

What this means for you: start with a structured physiotherapy programme. If meaningful pain and limitation persist after about 3 months, and imaging shows impingement without arthritis, arthroscopy is a reasonable, evidence-supported next step. Surgery is not a guaranteed cure, and the decision should weigh your goals, your sport and the risks.

Physiotherapy vs arthroscopy at a glance

Factor	Physiotherapy-led care	Hip arthroscopy
Best for	Most patients first; mild to moderate symptoms	Persistent symptoms after rehab; confirmed impingement; no significant arthritis
Recovery	Gradual gains over 3–6 months	Staged rehab over 4–9 months for athletes
Risks	Minimal	Infection, nerve irritation, stiffness, need for further surgery
Evidence	Improves symptoms in many patients	Greater improvement than physiotherapy at 8–12 months in three randomised trials

A 2019 meta-analysis in the American Journal of Sports Medicine found that about 1.7% of patients had a complication and about 5.5% needed further surgery, including later hip replacement.

Recovery and return to sport after hip arthroscopy

Phase	Typical timing	What happens
Protection	Weeks 0–4	Crutches as advised, protected weight bearing, gentle range of motion, stationary cycling
Early strength	Weeks 4–8	Walking without crutches, glute and core strengthening, swimming when cleared
Advanced strength	Weeks 8–12	Gym work, balance training, light jogging if pain-free
Sport-specific	Months 3–6	Running, cutting, kicking and sport drills
Return to competition	Usually 5–9 months	When strength and hop tests are close to the other side

These are typical ranges; your surgeon will tailor the plan to what was done in surgery.

What the research shows about sport:

A meta-analysis by Lovett-Carter and colleagues (Clinical Journal of Sport Medicine, 2020) found about 88% of athletes returned to sport and about 85% to their pre-injury level.
A stricter meta-analysis by Reiman and colleagues (BJSM, 2018) of 1,634 athletes found about 74% returned at their pre-injury level, on average 7 months after surgery.
Athletes with less cartilage damage and a shorter duration of symptoms before surgery tend to do best.

For non-surgical care, many people notice improvement within 6–12 weeks of consistent physiotherapy, with further gains over 3–6 months.

Can hip impingement cause arthritis?

FAI is considered a risk factor for early hip osteoarthritis, particularly cam-type shape with repeated impingement. Some researchers estimate that up to half of all hip arthritis may develop on a background of FAI.

However, most people with FAI shape never develop arthritis. There is not yet proof that surgery prevents arthritis: the 3-year FAIT results showed less cartilage damage on MRI after surgery but no difference on X-ray. Treating painful FAI before major cartilage damage gives the best chance of a good outcome.

Living with FAI: practical tips for Indian lifestyles

Use a chair rather than sitting on the floor for meals or long periods.
Choose a Western-style or raised toilet seat where possible.
Avoid deep squats and very low sofas during flare-ups.
Modify yoga poses that need deep hip bending, such as malasana or padmasana, until your physiotherapist clears them.
Warm up thoroughly before cricket, football or hockey, and keep up hip strength work through the season.

When to see a hip specialist

See an orthopedic or sports medicine hip specialist if:

Groin or hip pain lasts more than 2–4 weeks despite rest
Pain stops you playing sport, sitting comfortably or sleeping
Your hip clicks, catches or locks with pain
You notice reduced hip movement or a limp

Seek urgent care if you cannot bear weight after a fall; have severe hip pain with fever; develop sudden hip pain with a history of steroid or heavy alcohol use (possible avascular necrosis, loss of blood supply to the bone); or if a child or teenager develops a new limp or knee pain without injury.

Conclusion

Hip impingement is a common cause of groin pain in active adults, but an abnormal hip shape alone is not a diagnosis. The best evidence supports starting with targeted physiotherapy and activity changes. For carefully selected patients whose symptoms persist, hip arthroscopy offers a further, meaningful benefit.

At Sports Orthopedics Institute, our team can examine your hip, review your imaging and recommend a plan that fits your sport and lifestyle. Learn how our arthroscopy surgeon in Bangalore treats hip, knee and shoulder problems, read about hip arthroscopy and total hip replacement for advanced arthritis, explore our sports injury rehabilitation programme, or book a consultation.

Disclaimer: This article is for general education and is not a substitute for diagnosis or treatment by a qualified orthopedic surgeon. Hip pain has many causes and needs a proper examination.

Frequently asked questions

What does hip impingement pain feel like?

Usually a deep, aching or sharp pain in the groin or front of the hip, sometimes spreading to the outer hip or buttock. It is triggered by deep bending, squatting, long sitting, getting out of a car or twisting in sport. Some people also feel clicking, catching or stiffness.

Can hip impingement go away on its own?

The bone shape does not change, but symptoms often settle. Many people improve with activity changes and physiotherapy to strengthen the hip and core. If pain persists for several months despite good rehab, a specialist may discuss hip arthroscopy.

What is the best treatment for hip impingement?

For most people, the best first treatment is a personalised physiotherapy programme with activity modification and short-term pain relief. In three randomised trials, both physiotherapy and hip arthroscopy improved symptoms, with arthroscopy giving greater improvement at 8–12 months. Surgery suits patients with persistent symptoms and no significant arthritis.

What exercises should I avoid with hip impingement?

During flare-ups, avoid deep squats, deep lunges, heavy leg press with the hip bent past 90 degrees, and stretches that pull the knee towards the opposite shoulder. Long floor or cross-legged sitting can also aggravate pain. You do not need to stop exercising; your physiotherapist can swap these for hip and core strengthening.

Does femoroacetabular impingement need surgery?

Not always. Many people manage well with physiotherapy and activity changes. Surgery is usually considered when significant pain continues after at least 3 months of good non-surgical care, imaging confirms impingement with labral or cartilage damage, and there is no advanced arthritis.

How long is recovery after hip arthroscopy for FAI?

Most people use crutches for 2–4 weeks, return to desk work in 1–2 weeks and to light activity by about 3 months. Return to competitive sport takes about 7 months on average. Timelines depend on what was repaired and how consistently you follow rehab.

Does hip impingement cause arthritis?

It can raise the risk, particularly with cam-type shape and repeated impingement. However, most people with FAI shape never develop arthritis, and it is not yet proven that surgery prevents it. Early assessment of painful impingement gives the best chance of protecting the joint.

Is hip impingement common in Indian athletes?

Impingement-type hip shape is common in athletes worldwide, especially in sports with repeated deep hip bending, twisting and kicking, such as football, cricket, hockey and kabaddi. Floor sitting and deep squatting can make symptoms more noticeable. Reliable Indian prevalence figures are limited, so diagnosis relies on careful examination.

References (for the blog's Resources section)

Griffin DR, Dickenson EJ, O'Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement. Br J Sports Med. 2016;50(19):1169–1176. doi:10.1136/bjsports-2016-096743
Griffin DR, Dickenson EJ, Wall PDH, et al. Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): a multicentre randomised controlled trial. Lancet. 2018;391(10136):2225–2235. doi:10.1016/S0140-6736(18)31202-9
Palmer AJR, Ayyar Gupta V, Fernquest S, et al. Arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of symptomatic femoroacetabular impingement: multicentre randomised controlled trial (FAIT). BMJ. 2019;364:l185. doi:10.1136/bmj.l185
Palmer A, Fernquest S, Rombach I, et al. Medium-term results of arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of femoroacetabular impingement syndrome. Br J Sports Med. 2025;59(2):109–117. doi:10.1136/bjsports-2023-107712
Hunter DJ, Eyles J, Murphy NJ, et al. Multi-centre randomised controlled trial comparing arthroscopic hip surgery to physiotherapist-led care for femoroacetabular impingement syndrome on hip cartilage metabolism: the Australian FASHIoN trial. BMC Musculoskelet Disord. 2021;22:697. doi:10.1186/s12891-021-04576-z
FIRST Investigators (Ayeni OR, Karlsson J, Heels-Ansdell D, et al.). Osteochondroplasty and labral repair for the treatment of young adults with femoroacetabular impingement: a randomized controlled trial. Am J Sports Med. 2021;49(1):25–34. doi:10.1177/0363546520952804
Mansell NS, Rhon DI, Meyer J, Slevin JM, Marchant BG. Arthroscopic surgery or physical therapy for patients with femoroacetabular impingement syndrome: a randomized controlled trial with 2-year follow-up. Am J Sports Med. 2018;46(6):1306–1314.
Frank JM, Harris JD, Erickson BJ, et al. Prevalence of femoroacetabular impingement imaging findings in asymptomatic volunteers: a systematic review. Arthroscopy. 2015;31(6):1199–1204.
Lovett-Carter D, Jawanda AS, Hannigan A. Meta-analysis of the surgical and rehabilitative outcomes of hip arthroscopy in athletes with femoroacetabular impingement. Clin J Sport Med. 2020;30(4):404–411. PubMed
Reiman MP, Peters S, Sylvain J, et al. Femoroacetabular impingement surgery allows 74% of athletes to return to the same competitive level of sports participation but their level of performance remains unreported: a systematic review with meta-analysis. Br J Sports Med. 2018;52(15):972–981. doi:10.1136/bjsports-2017-098696
Minkara AA, Westermann RW, Rosneck J, Lynch TS. Systematic review and meta-analysis of outcomes after hip arthroscopy in femoroacetabular impingement. Am J Sports Med. 2019;47(2):488–500. doi:10.1177/0363546517749475
American Academy of Orthopaedic Surgeons. OrthoInfo: Femoroacetabular Impingement. orthoinfo.aaos.org

Groin Pain When You Squat or Sit Cross-Legged? Hip Impingement (FAI) Explained — Symptoms, Diagnosis and Evidence-Based Treatment