The correct way to do the leg extension

Trifocus Fitness Academy - leg extension
Personal/Fitness Training Blog

It takes a number of exercises in order to be successful in building up the powerhouse muscles which are on the front of your thigh. It’s worth including a mix of compound as well as isolation moves into your routine if you want to develop stronger quads.

What is the leg extension?

The leg extension is a steadfast isolation exercise which puts highlights your quads. It is the perfect complement to the leg curl that isolates the hamstrings. Together this pair of exercises will go a long way to bulking up the back and fronts of your thighs.

The proper form for the leg extension

Adjust the back of the seat as well as the footpad of the leg extension machine with the intention that when you sit in it your knees come to the edge of the bench. In addition, your ankles are just below the footpad rollers. Sit back with your back pushed firmly touching the back pad.

Take hold of the handles of the seat edges behind your hips and keep your upper body stable as your legs extend in a smooth controlled movement until they are fully extended. Contract your quadriceps at the top of the movement and then slowly lower the weight down to your starting position. Do as many reps as necessary for the desired results.

Safety tips for the leg extension

  • Monitor knee flexion
  • Cue your quads
  • Keep your lower back level with the bench
  • Try to get a good range of movement

Biomechanical analysis of the leg extension

The leg extension is a movement of the lower body that takes place in a sagittal/media plane and mainly uses the muscles of the legs. The actions are concerned with using a single joint, namely the knee. During the upward phase of the leg extension, the knee (which is a hinge joint formed from the tibia, femur, rectus femoris, vastus medialis, vastus lateralis and vastus intermedialis muscles) causes extension. The upward movement is a concentric muscle contraction.

During the downward phase, at the knee the rectus femoris, vastus medialis, vastus lateralis and vastus intermedialis muscles cause flexion. The downward movement is an eccentric muscle contraction.

The benefits of the leg extension

As previously mentioned, the leg extension targets the quadriceps, which are the big muscles on the front of the thigh. Theoretically, this is an “open chain kinetic” exercise and is different from a “closed chain kinetic exercise,” for example a squat. The variance is that, in the squat, the body part which you are exercising is anchored (feet on the ground) as opposed to in the leg extension, you’re moving the padded bar. This means your legs aren’t stationary as they work so the chain of movement is not closed in the leg extension.

The quads are well-developed during cycling however if your cardio is running or walking you are typically exercising the hamstrings which are located at the back of the thigh. If this is the situation, you may wish to develop the quads to be more in balance. developing your quads may also increase the force of kicking movements, which can be useful in sports such as soccer or, alternatively, martial arts.

Contact Trifocus Fitness Academy

Want to become a personal trainer and learn more about exercises such as the one above? If you do then follow this link.

Trifocus fitness academy personal training course registration