Lower limb
Vastus Medialis
Musculus vastus medialis
- Origin
- Medial lip of the linea aspera and the intertrochanteric region of the femur
- Insertion
- Via the quadriceps tendon onto the patella and further via the patellar ligament onto the tibial tuberosity; the most distal fibers (vastus medialis obliquus) attach directly to the medial patellar border
- Function
- Extends the knee and stabilizes the patella medially, especially in the terminal degrees of extension
- Innervation
- Femoral nerve (L2-L4)
- Movement & chain
- The oblique fibers (VMO) prevent lateral subluxation of the patella during the last 30° of extension - a frequent target of rehabilitation exercises for patellofemoral complaints.
- Palpation
- Medial-distal on the thigh, just above the patella, clearly visible/palpable during resisted active extension.
- Clinical
- Selective weakness/atrophy of the VMO is associated with patellofemoral pain syndrome and patellar instability.
- 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