The leg extension is a stalwart isolation exercise that puts all the focus on your quads and it acts as the perfect complement to the leg curl, which isolates the hamstrings.
Technique of Leg Extension Exercise
1) Sit on the machine, with both legs positioned under the pad. To maintain stability and positioning throughout the movement, ensure that you are holding onto the bars on the side and that your feet are pointing forwards.
2) As you exhale your breath, extend your legs using only your quadriceps until they are fully extended. Throughout this part of the movement, the only muscle that should be under stress and tension is the quadriceps; keep the rest of the body as still as possible.
3) Once the quadriceps has been fully extended, hold for one second and squeeze the working muscle.
4) As you inhale your breath, lower the weight back to the starting position in a controlled movement.
5) Once the legs are back in the starting position once again, repeat for the amount of repetitions required.
Benefits of leg extension
Leg extensions are a key exercise in strengthening the patellar ligament and quadriceps attachment for the knee. This exercise focuses on strengthening the quad alone and, therefore, strengthens key attachments for the knee joint at the same time. A machine-assisted training, it is a very good option for exercise beginners and you need not worry about form and posture. It is also a good finisher exercise, as it is an isolation exercise for quadriceps that can be performed after compound exercises like squats or dead lifts. You can focus on target muscles more selectively. While doing squats, you hit a lot of muscles at once and expend a lot of energy. With leg extensions, you focus just on quads. There is a common belief that leg extensions can be harmful for your knees. But in my opinion, it is a good exercise for people with knee problems as they are performed while seated, reducing the impact on the knee. However, it is advisable to reduce the weight load and focus on the squeeze instead. Also, if you are recovering from any leg injury, it is best to consult a doctor before embarking on this form of exercise.
Major muscles used in Leg Extension
The leg extension exercise works out just one major muscle group, your quadriceps, or “quads.” Your quads run along the front of your thigh from your knee to your pelvis and are responsible for hip flexion and knee extension. When you perform leg extensions, you contract the quad to bring your knees up against the weighted resistance. While many other exercises such as squats, lunges or deadlifts also provide a heavy workout for the quads, they do not isolate the muscle like a leg extension does.
The muscles involved in leg extensions are:
Rectus Femoris and Vastus Intermedialis