Lower limb
Gracilis
Musculus gracilis
- Origin
- Inferior border of the pubic symphysis and the inferior ramus of the pubic bone
- Insertion
- Pes anserinus on the medial side of the tibia
- Function
- Adduction of the hip, flexion of the knee and internal rotation of the lower leg with the knee bent
- Innervation
- Obturator nerve, predominantly L3
- Movement & chain
- As a two-joint muscle it couples hip adduction with knee movement; works together with sartorius and semitendinosus in the pes anserinus as a dynamic stabilizer against valgus loading of the knee.
- Palpation
- Palpable as the most superficial and most medial tendon of the pes anserinus, just below the medial knee crease.
- Clinical
- Widely used as a tendon graft in anterior cruciate ligament reconstructions because of its favorable length and limited functional deficit after harvest.
- Segmental innervation
- Predominantly L3, via the obturator nerve; part of the myotome testing pattern for hip adduction.
- In clinical practice
- Frequent repositioning to prevent trochanteric and heel pressure ulcers; ensure hip dislocation precautions in total hip arthroplasty patients.
- Region in the model
- Lower limb