Lower limb
Vastus Intermedius
Musculus vastus intermedius
- Origin
- Anterior and lateral surface of the shaft of the femur
- Insertion
- Via the quadriceps tendon onto the patella and further via the patellar ligament onto the tibial tuberosity
- Function
- Extends the knee
- Innervation
- Femoral nerve (L2-L4)
- Movement & chain
- Lies deep beneath rectus femoris and delivers pure knee extension force without influencing the hip.
- Palpation
- Not directly distinguishable due to being covered by rectus femoris, vastus medialis and vastus lateralis.
- Clinical
- With prolonged immobilization or after knee surgery, this is often the first quadriceps head to atrophy; also involved in quadriceps tendon ruptures.
- Segmental innervation
- Femoral nerve, L2-L4.
- 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