A Guide to the Muscles of the Leg

Leg muscles are some of the largest and strongest muscles in the body. Before trying to grow them in size, it is important to first understand their anatomy. By knowing where they are located and what they do, each of them can be targeted with specific exercises. There are three major muscles groups in the leg:


The quadriceps femoris is a large muscle group located in the upper leg and consists of four primary muscles:

Rectus Femoris – front side of the thigh
Vastus lateralis – outside of the thigh
Vastus medialis – inside of the thigh
Vastus intermedius – also on the front side of the thigh

Located on the front and side of the thigh, all four of these muscles connect the front of the pelvic bone and femur (the large bone running from the hip to the knee in the upper leg) to the tibia (the large bone running from the knee to the ankle in the lower leg) via the patellar tendon that runs along the outside of the knee. The quadriceps are responsible for the extension or straightening of the leg at the knee.



The hamstring group comprises of three primary muscles:

Biceps Femoris – runs midline to the outside down the back of the thigh
Semimembranosus – runs along the inside of the thigh down the back of the leg
Semitendinosus – runs from midline down the back of the thigh

All three muscles connect at ischium (a bone on lower end of the pelvis), run down the leg, across the knee and connects at the tibia just below the knee. The hamstring serves two purposes – to extend the thigh (as in standing up from a seated position) and to rotate the leg laterally (move the lower leg to the inside and across the other leg).



The calf muscle group is located on the backside of the lower leg and is comprised of two muscles – the gastrocnemius and soleus. The first one connects at the bottom end of the femur in the upper leg and to the Achilles tendon at the other end. It is largely responsible for pushing the body forward when running or walking. It also allows the leg to bend at the knee. The soleus runs under the gastrocnemius and connects at the tibia and fibula at one end and the Achilles tendon at the other end. It is responsible for the plantar flexion of the foot - a decrease of the angle between the foot and lower leg as in standing on your tiptoes.


Building Leg Muscle

Here are some exercises that target each of the leg muscle groups:

Quadriceps – Sprints, step-ups, lunges, squats and leg presses
Hamstrings – Deadlifts , leg curls and squats
Calfs – calf raises, leg presses, dumbbell squats

As with any of the large muscle groups, perform exercises that build all of the muscles in the extremity equally. Otherwise you increase your risk for an injury from imbalanced strength.