A group of four large muscles on the front of the thigh that extend the knee and stabilize the kneecap.
Structure
The quadriceps comprises four heads: the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. They converge into the quadriceps tendon, which encases the patella and continues as the patellar ligament to the tibial tuberosity.
Function
The vasti act on the knee alone, while the rectus femoris crosses the hip as well, contributing to hip flexion. Together they generate the force needed to stand from sitting and to propel the body forward in gait.
Clinical note
The quadriceps tendon’s strong reflex contraction in response to a patellar tap is the basis of the knee-jerk test.
Find more body parts by letter
Quadriceps starts with Q and ends with S. Browse other body parts along the same letter.
Body Parts that contain a letter from "Quadriceps":