Groin pain is a common issue among athletes, particularly in sports that involve sprinting, sudden changes of direction, or kicking. While muscle strains are the most frequent cause, another possible cause is obturator nerve entrapment. This condition is less well-known but can cause ongoing obturator nerve pain that is often difficult to diagnose without careful assessment.

What Is the Obturator Nerve?

The obturator nerve comes from the lower back (lumbar spine) and travels through the pelvis into the inner thigh. It passes through the obturator foramen and divides into two branches: the anterior branch supplies the adductor longus and brevis and gracilis muscles and sensation to the medial thigh; the posterior branch supplies the adductor magnus and the back of the knee joint. 

When the nerve becomes irritated or compressed, a condition referred to as obturator nerve entrapment, it can lead to groin and adductor pain, weakness, and loss of function. Causes of entrapment include fascia thickening in the adductor muscle region and pathology in the pelvis or hip, such as cysts or growths.  

obturator nerve map

Symptoms of Obturator Nerve Pain

Athletes with obturator nerve pain often describe: 

  • Aching or burning pain in the inner thigh or groin, usually triggered by running 

  • Pain that gets worse with sprinting, side steps, or kicking

  • Weakness of the inner thigh muscles (adductors)

  • Numbness and paraesthesia over the medial thigh 

  • A feeling of the leg “not working properly” during sport

  • Usually, symptoms are relieved almost immediately by rest 

  • Symptoms that don’t improve with standard groin strain treatments

Sometimes, the pain may spread into the knee or even feel as though it originates from the hip.

Clinical Assessment

A sports doctor will typically begin by taking a history and conducting an examination to determine if the problem is musculoskeletal or nerve-related. Signs that suggest obturator nerve entrapment include:

  • Tenderness along the inner thigh, close to where the nerve passes

  • Weakness when squeezing the legs together (adduction)

  • Pain is reproduced with the stretching of the inner thigh

  • No significant findings of osteitis pubis, hip joint pathology, stress fractures, hernias or urological problems

It is essential that your doctor systematically excludes other causes of groin pain in athletes. 

Investigations

As obturator nerve pain can look similar to other causes of groin pain, investigations are often needed:

  • MRI scan: Helps rule out hip joint, pubic symphysis or muscle injuries. It may also show wasting of the adductor muscles or mass lesions in the pelvis. 

  • Ultrasound: Can look for nerve compression or scar tissue in the groin area. It can also exclude an inguinal or femoral hernia. 

  • Nerve conduction studies (EMG): Sometimes used to check the function of the obturator nerve, though not always necessary.

  • Diagnostic injection: An anaesthetic injection directed with ultrasound guidance around the obturator nerve can help confirm if it is the source of pain. To be positive, the block needs to abolish the pain. 

Treatment of Obturator Nerve Entrapment

Treatment depends on how severe the problem is, but most cases start with conservative care:

  • Rest and load management: Reducing sprinting, side-step drills, or kicking until symptoms settle.

  • Physiotherapy focuses on stretching and strengthening the hip and groin muscles, as well as correcting biomechanical issues.

  • Medication: NSAIDs may be used for short-term relief.

  • Ultrasound-guided injections: Corticosteroid or nerve hydrodissection injections around the obturator nerve can reduce inflammation and release pressure. Doctors use ultrasound guidance to inject the anterior and posterior branches of the obturator nerve close to the obturator foramen. Generally, we use a combination of local anaesthetic, 5% dextrose and a small dose of cortisone. 

  • Surgery is rarely needed, but in stubborn cases, surgical decompression of the obturator nerve may be considered.

Final Word from Sportdoctorlondon about Obturator Nerve Entrapment 

Obturator nerve entrapment is an uncommon but important cause of persistent groin pain in athletes. Unlike a typical muscle strain, obturator nerve pain typically does not improve with rest or standard rehabilitation alone. With careful diagnosis, targeted physiotherapy, and in some cases guided injections, athletes can recover fully and return to their sport.

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