Lower limb
Posterior cutaneous nerve of thigh (Posterior femoral cutaneous nerve)
Nervus cutaneus femoris posterior
- Origin
- Arises from the sacral plexus anterior rami S1, S2, S3
- Insertion
- Exits the pelvis through the infrapiriform foramen deep to gluteus maximus, descends beneath the fascia lata down the posterior midline of the thigh to the popliteal fossa
- Function
- Pure sensory innervation to inferior buttock (inferior clunial nerves), perineum, posterior thigh, and upper posterior calf
- Innervation
- Pure sensory nerve (S1–S3)
- Movement & chain
- Glides beneath the deep fascia over the hamstrings
- Palpation
- Sensory examination along the posterior midline of the thigh
- Clinical
- Entrapment causes chronic sitting pain over the ischial tuberosity and posterior thigh dysesthesias; mimics true sciatica
- Segmental innervation
- S1, S2, S3 spinal cord levels
- In clinical practice
- Evaluated in refractory posterior thigh pain to differentiate local cutaneous entrapment from lumbar radiculopathy
- Region in the model
- Lower limb