The Quadriceps Muscle, or simple, The Quads
The quadriceps muscle is a group of four muscles located in the anterior thigh on both sides of the body and are needed to be strong and quick for faster running speed. Their names are: 1) Vastus Rectus (a.k.a. Rectus Femoris), 2) Vastus Medialis, 3) Vastus Lateralis, and 4) Vastus Intermedialis. These muscles are shown in Figure 1 below:
Figure 1. The Quadriceps Muscle.
Innervation, or, Nerve Supply to the Quadriceps Muscle
The nerve supply to the quadriceps muscles is supplied by the the femoral nerve . See Figure 2:
Figure 2. LumboSacral Plexus showing the Femoral Nerve.
Function of the Quads
The quadriceps muscle’s main function is to extend the leg at the knee. This occurs during activities such as sprinting, jogging, jumping, kicking and walking. This is illustrated by the athlete’s right leg in Figure 3 below:
Figure 3. Leg extended at the knee.
Muscles involved: R-Vastus Rectus, R-Vastus Medialis,
R-Vastus Lateralis, and R-Vastus Intermedialis
Because one of the four quadriceps muscles also crosses the hip joint, it make it a hip flexor as well. The muscle I am referring to is the rectus femoris, so, this muscle has two functions, knee extension as just explained and hip flexion. If you look at the athlete’s left leg in the image above, you will see his left thigh, or, hip is flexed upward and this hip flexion action is accomplished in part by the rectus femoris muscle.
Antagonist Muscles
Muscles that work opposite the quadriceps are 1) the hamstrings, which are knee flexors and work opposite knee extension, and 2) the hip extensors, which work opposite the rectus femoris’s hip flexion action. The hip extensors include the glutes and yes, hamstrings. It is not uncommon for muscles to have more than one function and this is the case here with both the quadriceps and hamstrings. I will talk more about the hip extensors in another post.
Best Exercises for the Quadriceps
When it comes to the quads, there is no shortage of exercises one can do. Examples include leg extensions, squats and lunges. However, to really target in a safe and effective way for speed, the Run Faster With Isometric Training program has proven to be a valuable resource for many athletes, both young and old.
