By Mr Ahmed-Ramadan Sadek, Neurosurgeon · 9 min read

📄 Download a one-page summary to print or share (PDF)

Why buttock and leg pain can be confusing

The sciatic nerve starts as several nerve roots leaving the lower spine. It travels through the pelvis, passes deep in the buttock beneath a group of small muscles, and runs down the back of the thigh towards the foot.^[1][3] Irritation anywhere along this path can cause similar pain.

Doctors separate true sciatica, from the nerve roots in the spine, from pain caused further along the nerve. NICE’s summary for GPs lists piriformis syndrome, also called deep gluteal syndrome, as one of these causes, along with hip and sacroiliac joint problems that can mimic sciatica.^[4]

Sciatica from the spine

Here a nerve root is irritated as it leaves the spine. A slipped disc is the most common cause. Lumbar spinal stenosis, a narrowing of the space for the nerves, is another.^[1]

Typical features

• Pain in one leg that spreads below the knee, often to the foot or toes.^[1][4]
• Leg pain that is worse than any back pain.^[1][4]
• Pins and needles or numbness in a strip of skin supplied by one nerve root. Doctors call this a dermatomal pattern.^[4]
• Sometimes weakness or changed reflexes in the muscles that nerve root supplies.^[4]
• Pain that may be worse with bending, twisting, coughing or sneezing.^[1][4]

A common examination is the straight leg raise. You lie on your back and the doctor slowly lifts your straight leg. If this brings on your leg pain before the leg reaches about 60 degrees, the test is called positive.^[4] A Cochrane review found it picks up most people with a disc problem in groups having surgery, but it is also positive in many people without one. It is a clue, not proof.^[5]

Is an MRI scan needed?

Often not straight away. NICE advises against routine scans in a non-specialist setting such as a GP surgery. A scan is considered in a specialist setting, such as a musculoskeletal clinic or hospital, only if the result is likely to change your treatment.^[6] Most sciatica gets better within a few weeks to a few months.^[1] See our sciatica guide for treatment.

Piriformis syndrome and deep gluteal syndrome

The piriformis is a small muscle deep in the buttock, and the sciatic nerve passes close to it. The idea that this muscle can squeeze or irritate the nerve has been around for many decades, yet it is still debated.^[7] Specialists now often use the wider term deep gluteal syndrome. This is because the nerve can also be caught by bands of tissue, other small muscles, blood vessels or the hamstring attachment.^[8][3]

There is no agreed single test. Studies of how common the condition is are few, and the larger ones are at high risk of bias.^[9] In practice it is usually diagnosed after a spinal cause has been looked for and ruled out.^[3][10]

Typical features

Systematic reviews of published cases found four features came up most often:^[7][9]

• Pain in the buttock.
• Pain that is worse when sitting. A review of deep gluteal syndrome found that difficulty sitting for 30 minutes was a common complaint.^[10]
• Tenderness deep in the buttock, near the notch in the pelvis where the nerve leaves.
• Pain brought on by movements that stretch or tighten the piriformis muscle.

Back pain is usually mild or absent.^[4] Doctors may test hip movements, such as bending the hip, bringing the knee across the body and turning the hip inwards (the FAIR position), or seated stretch tests.^[11][12] There is no agreed test, and studies of these tests have reported varying results.^[12] A systematic review concluded that the accuracy of the symptoms and tests cannot yet be judged from the studies available.^[9] The straight leg raise is often normal, so a normal result does not rule this condition out.^[9][12]

Tests

An MRI of the lower spine helps rule out a spinal cause. In specialist centres, an MRI of the pelvis and buttock, sometimes using a detailed nerve technique called MR neurography, can show the nerve and anything pressing on it.^[8][10] A diagnostic injection guided by a scan can also help. If numbing the area eases the pain, that points to the buttock as the source, and the injection may bring some relief as well.^[8][3]

Treatment

• Physiotherapy, including stretching and strengthening programmes, is the usual first step.^[3][13]
• Changing activities that bring on the pain, such as long spells of sitting.^[14]
• Guided injections, for example a local anaesthetic and steroid injection near the muscle or nerve.^[3][13]
• Surgery to free the nerve, by open or keyhole operation, only in the small number of people who have not improved with other treatment.^[3][14][13]

The evidence is weak and results vary widely. In one large US study with no comparison group, 79% of people improved by at least half with injection and physiotherapy.^[11] By contrast, a 2023 systematic review of 13 small studies (508 people) found that only three trials showed a meaningful fall in pain. It rated the evidence as low quality, could not recommend one treatment over another, and advised physiotherapy first, as for other back pain and sciatica.^[13]

Ischiofemoral impingement

The ischium is the sitting bone. Between it and the top of the thigh bone (femur) is a narrow gap containing a small muscle called the quadratus femoris. If the gap is too narrow, the muscle can be pinched as the hip moves. This is ischiofemoral impingement.^[15][16] The sciatic nerve runs just behind this muscle, so it can be irritated too.^[3][17]

It is an uncommon cause of pain in the hip, buttock and groin, and some people notice a snapping feeling.^[17] Pain is often brought on by walking with long strides as the hip straightens behind you, and there may be tenderness just beside the sitting bone.^[3] It is seen more often in women. In the first MRI study all nine people affected were women aged 30 to 71,^[15] and in a later pooled analysis 133 of 154 people were women.^[18]

How it is diagnosed

MRI is the main test.^[16] It shows a narrowed space between the bones and swelling (oedema) in the quadratus femoris muscle.^[15][18] The measurements overlap with people who have no symptoms, so the scan has to be read alongside your symptoms and examination. An injection into this space can help confirm the diagnosis and may ease pain.^[16]

Treatment

Non-surgical treatment comes first, such as physiotherapy and changing activities, with a guided steroid injection if needed.^[16][17] Keyhole or open surgery is kept for people who do not improve. A systematic review found 17 studies, all case series or single case reports with no comparison groups, so no one treatment can be called the best.^[17]

Comparing the three

	Sciatica from the spine	Piriformis or deep gluteal syndrome	Ischiofemoral impingement
Where the pain is	Leg pain worse than back pain, usually below the knee to the foot	Buttock, may spread down the back of the thigh; little or no back pain	Deep buttock or hip, sometimes groin
What makes it worse	Bending, twisting, coughing, sneezing	Sitting	Walking with long strides
Key examination clues	Positive straight leg raise; numbness or weakness in one nerve root pattern	Tenderness deep in the buttock; pain with hip stretch tests	Tenderness beside the sitting bone; pain as the hip straightens behind you
Most useful test	MRI of the lower spine, if it would change treatment	MRI to rule out the spine; pelvic MRI or diagnostic injection in specialist centres	MRI of the hip and pelvis
First treatment	Keep active, exercise, physiotherapy	Physiotherapy and stretching, activity changes	Physiotherapy, activity changes; guided injection if needed

This is a simplified summary.^{[1][4][7][3][17]} Symptoms often overlap.

Why the right diagnosis matters

Treatment is aimed at where the problem is. Spinal decompression surgery is considered for sciatica when non-surgical treatment has not helped and the scan findings match the symptoms.^[6] It will not help pain coming from the buttock. In the same way, an injection or operation in the buttock will not help a trapped nerve root in the spine. That is why specialists check the lower back first, before turning to the buttock.^[3]

Other causes to consider

Several other conditions can cause pain in the buttock or leg:^[4][3]

• Hip joint problems, such as arthritis.^[4]
• Sacroiliac joint pain, from the joint between the base of the spine and the pelvis. See our sacroiliac joint pain guide.^[4]
• Hamstring tendon problems where the tendon attaches to the sitting bone, which can also irritate the nearby sciatic nerve.^[3]
• Trochanteric pain on the outer side of the hip.^[4]

When to get help

See your GP if your pain has not improved after a few weeks of home treatment, is getting worse, or is stopping you doing normal activities. In many areas you can also refer yourself to an NHS physiotherapy (musculoskeletal) service.^[1]

Frequently asked questions

Further reading

• NHS: Sciatica
• NICE NG59: Low back pain and sciatica in over 16s
• Spinemathema guide: Sciatica
• Spinemathema guide: Slipped disc
• Spinemathema guide: Lumbar spinal stenosis
• Spinemathema guide: Sacroiliac joint pain

References

1. NHS. Sciatica. NHS website; page last reviewed 3 December 2024. Link
2. NHS. Back pain. NHS website; page last reviewed 5 March 2026. Link
3. Martin HD, Reddy M, Gómez-Hoyos J. Deep gluteal syndrome. J Hip Preserv Surg. 2015;2(2):99-107. Link
4. National Institute for Health and Care Excellence. Clinical Knowledge Summaries: Sciatica (diagnosis, differential diagnosis, red flag symptoms and signs, management). Last revised August 2026. Link
5. van der Windt DA, Simons E, Riphagen II, et al. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database Syst Rev. 2010;(2):CD007431. Link
6. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management (NG59). Published 30 November 2016; last updated 29 July 2026. Link
7. Hopayian K, Song F, Riera R, Sambandan S. The clinical features of the piriformis syndrome: a systematic review. Eur Spine J. 2010;19(12):2095-2109. Link
8. Hernando MF, Cerezal L, Pérez-Carro L, Abascal F, Canga A. Deep gluteal syndrome: anatomy, imaging, and management of sciatic nerve entrapments in the subgluteal space. Skeletal Radiol. 2015;44(7):919-934. Link
9. Hopayian K, Danielyan A. Four symptoms define the piriformis syndrome: an updated systematic review of its clinical features. Eur J Orthop Surg Traumatol. 2018;28(2):155-164. Link
10. Kizaki K, Uchida S, Shanmugaraj A, et al. Deep gluteal syndrome is defined as a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2020;28(10):3354-3364. Link
11. Fishman LM, Dombi GW, Michaelsen C, et al. Piriformis syndrome: diagnosis, treatment, and outcome, a 10-year study. Arch Phys Med Rehabil. 2002;83(3):295-301. Link
12. Martin HD, Kivlan BR, Palmer IJ, Martin RL. Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region. Knee Surg Sports Traumatol Arthrosc. 2014;22(4):882-888. Link
13. Hopayian K, Mirzaei M, Shamsi M, Arab-Zozani M. A systematic review of conservative and surgical treatments for deep gluteal syndrome. J Bodyw Mov Ther. 2023;36:244-250. Link
14. Park JW, Lee YK, Lee YJ, Shin S, Kang Y, Koo KH. Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain. Bone Joint J. 2020;102-B(5):556-567. Link
15. Torriani M, Souto SC, Thomas BJ, Ouellette H, Bredella MA. Ischiofemoral impingement syndrome: an entity with hip pain and abnormalities of the quadratus femoris muscle. AJR Am J Roentgenol. 2009;193(1):186-190. Link
16. Hernando MF, Cerezal L, Pérez-Carro L, Canga A, González RP. Evaluation and management of ischiofemoral impingement: a pathophysiologic, radiologic, and therapeutic approach to a complex diagnosis. Skeletal Radiol. 2016;45(6):771-787. Link
17. Nakano N, Shoman H, Khanduja V. Treatment strategies for ischiofemoral impingement: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2020;28(9):2772-2787. Link
18. Singer AD, Subhawong TK, Jose J, Tresley J, Clifford PD. Ischiofemoral impingement syndrome: a meta-analysis. Skeletal Radiol. 2015;44(6):831-837. Link

This article is general information and is not a substitute for advice about your own situation. Please speak to your GP or specialist before making any change to your treatment.

Last checked: October 2026