The quadriceps muscles make up much of the anterior, or front side, of the thigh. The four muscles of the quadriceps are the rectus femoris, vastus lateralis, vastus intermedius and the vastus medialis. While the quadriceps muscles work in conjunction to perform various movements, each has unique characteristics. These muscles vary in terms of location, function, potential for injury and the exercises that target them.
Rectus Femoris
The rectus femoris is the most centrally located of the quadriceps muscles. Knee extension is the main function of this muscle. Of the quadriceps muscles, it is the only one that is also involved in hip flexion, since it originates at the pelvis. The rectus femoris can rupture or become inflamed at the upper part. The main cause of this condition is overuse through kicking or explosive movements such as sprint starts. Rest, cold therapy and compression can be used to help the injury heal. Exercises to target the rectus femoris include squats and lunges.
Vastus Lateralis
The largest of the quadriceps muscles, the vastus lateralis, is located on the outermost portion of the thigh. Like the rectus femoris, this muscle's main function is knee extension. Injuries to the vastus lateralis can occur from activities like running and jumping but also from prolonged periods of sitting with the knee flexed. Cycling and walking up stairs are two exercises that activate the vastus lateralis.
Vastus Intermedius
The vastus intermedius sits at the upper portion of the mid-thigh under the rectus femoris. Knee extension is the main function of this muscle. Overdevelopment of outer thigh muscles can lead to lead to runner's knee, a condition characterized by pain at the front of the knee. The vastus intermedius is often the muscle injured when someone has runner's knee. Including inner thigh exercises will help relieve this condition. Leg presses are one example of an exercise that will work the vastus intermedius.
Vastus Medialis
Often called the "teardrop muscle," the vastus lateralis is located on the inner thigh just above the kneecap. Like the rectus femoris and other vastii, its main function is knee extension. Weakness of the vastus lateralis is another cause of runner's knee. Temporarily avoiding exercises where the knee is bent will also help relieve this condition. Lunges are an exercise that strengthens the vastus lateralis.
Member Comments