Lower limb
Kneecap
Patella
- Origin
- Embedded within the quadriceps femoris tendon; articulates posteriorly with the patellar surface of the femur
- Insertion
- Continues distally as the patellar ligament to the tibial tuberosity
- Function
- Largest sesamoid bone in the human body; increases the mechanical leverage of the quadriceps muscle during knee extension
- Innervation
- Femoral nerve (L2–L4)
- Movement & chain
- Glides proximally and distally along the femoral trochlear groove during knee flexion and extension
- Palpation
- Easily palpable on anterior aspect of the knee; mobile when quadriceps is relaxed
- Clinical
- Patellar dislocation (commonly lateral); patellofemoral pain syndrome (PFPS); patellar fracture; chondromalacia
- Segmental innervation
- L2–L4
- In clinical practice
- Key site for eliciting the patellar tendon reflex (knee jerk, L3–L4) and patellar mobilization
- Region in the model
- Lower limb