Exercise Profile
  • Target Muscle Group
  • Exercise TypeStrength
  • Equipment RequiredMachine
  • MechanicsIsolation
  • Force TypePush (Unilateral)
  • Experience LevelBeginner
  • Secondary Muscles
Target Muscle Group


Quads Muscle Anatomy Diagram

Single Leg Extension Overview

The single leg seated leg extension is a variation of the leg extension and an exercise used to target the muscles of the quads.

This exercise can be particularly hard on the knees. So, for those with prior knee issues, it may be beneficial to stick with other movements, preferably compound, to target your quads.

The leg extension is a great exercise for quad development and may be beneficial to include in your workout routines if your goals are more aesthetics-driven.

The leg extension can be utilized in both leg workouts and full body workouts.

Single Leg Extension Instructions

  1. Select the desired resistance on the weight stack and insert the pin.
  2. Adjust the seat so that the knees are directly in line with the axis of the machine.
  3. Sit down and position one shin behind the pad at the base of the machine.
  4. Take a deep breath and extend your leg as you flex your quadricep.
  5. As you lock out the knee, exhale to complete the repetition.
  6. Slowly lower your foot back to the starting position and repeat for the desired number of repetitions on both sides.

Single Leg Extension Tips

  1. Ensure the axis of rotation for the knee directly matches that of the machine. In other words, the point of rotation for the machine should be in line with your knee joint itself. If the knee is positioned too far in front or behind the axis of rotation, there will be excessive stress added to the joint which could cause significant injury.
  2. Typically extensions should not be done excessively heavy due to the lack of hamstring co-contraction with the quads. When one occurs in isolation it could present an injury risk to the knee if done with excessive weight.
  3. Pointing the toes can help to enhance mind muscle connection.