Leg extension, machine

Leg extension, machine is an exercise for the extensors of the thigh (m. quadriceps femoris). Due to its simplicity it is very suitable for beginners.

Leg extension, machine

Muscles involved in leg extension, machine



Correct execution

  • Sit in the leg extension machine and adjust the seat so that the knee joint axis is aligned with the machine´s rotation axis and your back is firmly against the seat back.
  • Now position the foot roll so that it rests just above the foot on the shin in a normal sitting position.
  • Hold on to the handholds with your hands.
  • Begin the exercise by raising the tips of your feet, tensing your leg muscles and slowly extending your knee joints against the weight of the roller (but do not hyperextend).
  • Pause briefly in the final position and then bend the knees again to approx. 90° – this maintains the tension in the muscles of the front thighs.

Common mistakes with leg extension, machine

  • Too much weight: too much weight will prevent you from performing the exercise correctly. This reduces the training effect and increases the risk of injury. 
  • Momentum: If you move the weight with momentum, you relieve the target muscles and thus reduce the training effect.  Consequently, you should avoid swinging movements and get the strength isolated from the m. quadriceps femoris.
  • Incorrect seating position: When choosing the seating position, the knee joint axis has to be aligned with the machine´s rotation axis. Adjust the seat cushion carefully to avoid knee injuries.
  • Wrong position of the foot roll: The foot roll should press against your lower shins just above the feet. Make sure the position doesn’t slip