Groin, thigh, and knee pain are common complaints in athletes. Muscle strains, hip joint injuries, or overuse of the hip joint are the most common causes. However, a less well-known but significant cause is femoral nerve entrapment. This condition occurs when the femoral nerve becomes compressed or irritated along its course, resulting in weakness, altered sensation, and persistent pain in the thigh. Recognising this early is essential to prevent ongoing symptoms and reduced performance.

What Is the Femoral Nerve?

The femoral nerve arises from the lumbar spine (L2–L4) and travels through the pelvis, passing beneath the inguinal ligament to reach the thigh. It supplies the quadriceps muscles (critical for running, jumping, and kicking) and sensation to the front of the thigh and inner lower leg. The saphenous nerve arises from a branch of the femoral nerve and runs down the inner lower leg. When compressed or injured, athletes may experience thigh pain, numbness, or weakness that interferes with their ability to participate in sports. 

Risk factors for femoral nerve entrapment or injury include direct trauma to the thigh from sport, gynaecological surgery, or compression from cysts or growths

groin ma showing femoral nerve

Symptoms of Femoral Nerve Entrapment

Athletes with femoral nerve pain may notice:

  • Aching, burning, or sharp pain in the groin, front of the thigh, or inner knee

  • Numbness or tingling on the front of the thigh or inner lower leg

  • Weakness when kicking, sprinting, or climbing stairs due to quadriceps involvement

  • Feeling that the leg “gives way” during activity

  • Pain worsened by hip extension or prolonged running

Clinical Findings

On examination, sports doctors may find:

  • Weakness in knee extension (quadriceps) compared with the other side

  • Reduced sensation in the anterior thigh or medial calf

  • Pain or discomfort reproduced by stretching the femoral nerve (e.g. hip extension with knee flexion – the femoral nerve stretch test)

  • No tenderness directly over the muscles, which helps distinguish it from a quadriceps strain

Investigations

Several tests may be used to confirm femoral nerve entrapment and exclude other causes of thigh pain: 

  • MRI of the lumbar spine and pelvis: to rule out disc herniation or pelvic pathology compressing the nerve

  • Ultrasound: can assess the femoral nerve in the groin region and check for entrapment under the inguinal ligament or the front of the thigh

  • Nerve conduction studies: to assess nerve function and confirm femoral nerve involvement

  • Diagnostic nerve block: an injection of local anaesthetic using ultrasound guidance around the femoral nerve may temporarily relieve femoral nerve pain, confirming the diagnosis.

Treatment of Femoral Nerve Entrapment

Treatment depends on severity and the underlying cause but usually starts conservatively.

  • Rest and activity modification: Avoiding aggravating activities such as sprinting or high-load kicking until symptoms improve

  • Physiotherapy: Strengthening surrounding muscles, improving hip mobility, and correcting biomechanics to reduce stress on the femoral nerve

  • Medication: Anti-inflammatory agents or neuropathic pain medications may be used in some cases. Nerve medications include amitriptyline and duloxetine. 

  • Ultrasound-guided injection: Corticosteroid or nerve hydrodissection injections around the nerve can reduce inflammation and relieve pressure

  • Surgery: Rarely needed, but decompression may be considered if conservative measures fail or if a structural cause, such as a tumour or mass, is identified

Final Word from Sportdoctorlondon about Femoral Nerve Entrapment

Although uncommon, femoral nerve entrapment should be considered in athletes with persistent groin, thigh, or knee pain not explained by muscle or joint injuries. Careful assessment, targeted investigations, and tailored treatment can provide excellent outcomes. With the right management, athletes usually return to sport without long-term limitations.

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