Muscles Worked. The primary mover during the seated or lying leg extension exercise is a group of four muscle heads on the front of the thigh, collectively referred to as the quadriceps. The largest muscle head is the rectus femoris, which sits in the center of the front thigh. The vastus intermedius lies under the rectus femoris.
Stabilizer muscles do not move the way agonist and antagonist muscles do during exercise. Instead, they help the rest of the body to remain relaxed and absorb shock, so the primary muscles can do the necessary work to perform the action. The trapezius muscles stabilize your torso and hips so your thighs can lift and lower during leg extensions.
A trainer may send you to the leg curl or leg extension machine to work your legs. These two machines work the opposing sides of your thighs. Use a leg curl machine to load the muscles in the back or posterior of the leg, primarily the hamstrings. The leg extension machine has you straighten your ...
According to About.com, the quadriceps are the primary muscles used in leg extensions. The quadriceps are located on the front of the thighs and include the rectus femoris, vastus intermedius, vastus lateralis and vastus medialis muscles.
Muscles Used. Leg extensions target your quadriceps. This large muscle group located on the front of your thigh contains four muscles. Three of the muscles -- known collectively as the vasti -- are only capable of extending the knee joint. The fourth muscle -- the rectus femoris -- can extend the knee and flex, or bend, the hip.
Leg extension alternative exercises work more muscles than just a simple leg extension, and are less likely to cause an injury. Subscribe. 8 Alternatives to Leg Extension Exercises.
Leg exercises such as step-ups, leg presses, and squats which can also be used to work the quadriceps use the calves, hamstrings and glute muscles to assist during movement but the leg extension machine focuses solely on the quadriceps which makes it the best exercise for strengthening weak quads.
Leg presses and leg extensions are both machine exercises that work muscles in your lower body, specifically the quadriceps. Resistance machine exercises are often an effective way for beginners to make a start in strength training, according to the McKinley Health Center at the University of Illinois.
Leg extensions are exercises usually done with a lever machine. You sit on a padded seat and raise a padded bar with your legs. The exercise works mainly the quadriceps muscles of the front of the thigh—the rectus femoris and the vastus muscles.
Main Muscle Worked: Quadriceps Equipment: Machine ... 8.5 Excellent Leg Extensions Images Show female images and videos Leg Extensions Instructions For this exercise you will need to use a leg extension machine. First choose your weight and sit on the machine with your legs under the pad (feet pointed forward) and the hands holding the side ...