StyrkiStyrki
AI CoachExercisesBlogHelp Center
Sign inGet the app
StyrkiStyrki
AI Coach|Exercises|PB Tracker|Blog|Help Center|Privacy Policy|Terms of Service

© 2026 Styrki. All rights reserved.

Exercise Library/Quads/Machine/One-Legged Leg Extension
Back to Library

One-Legged Leg Extension

MachineUnilateralStrength

No video available

The One-Legged Leg Extension is a unilateral strength exercise performed on a leg extension machine, extending one leg at a time against the machine's resistance pad to isolate the quadriceps. It primarily works the quads while your core and the seat back stabilize your torso. This exercise benefits athletes, beginners, or anyone seeking to improve knee extension power and correct side-to-side strength imbalances, and requires a leg extension machine.

How to Perform One-Legged Leg Extension

  1. 1Sit on a leg extension machine with your back flat against the pad and knees aligned with the machine's pivot point. Adjust the shin pad to rest just above your ankles.
  2. 2Grip the side handles for stability and position only your right foot behind the shin pad; let your left foot rest to the side or on the footrest, not under the pad.
  3. 3Set the machine to an appropriate weight, then start with your right knee bent at about 90 degrees, shin pad resting against your lower shin.
  4. 4Inhale to prepare, then exhale as you extend your right leg by straightening your knee, lifting the pad until your leg is fully extended.
  5. 5Pause briefly at the top, squeezing your right quad.
  6. 6Inhale as you slowly lower the pad back to the starting position with control.
  7. 7Perform 8-12 reps on the right leg, then reposition your left foot under the pad and repeat on the left leg.
  8. 8Key form tips: Keep your back flat against the pad and hips still throughout; avoid using momentum—control both the lift and the lowering phase. Common mistakes: Locking the knee out forcefully at the top or letting the hips lift off the seat.

Muscles Worked

Front

Back

Primary
Secondary
Primary
Quads

Equipment Required

Machine

Track this exercise

Log your sets, track PRs, and monitor progress with Styrki.

Start tracking free

Quick answers

What muscles does One-Legged Leg Extension work?
One-Legged Leg Extension primarily targets the Quads.
What equipment do I need for One-Legged Leg Extension?
One-Legged Leg Extension requires Machine. Make sure to select an appropriate weight for your fitness level.
Is One-Legged Leg Extension a unilateral exercise?
Yes, One-Legged Leg Extension is a unilateral exercise, meaning it works one side of your body at a time. This helps identify and correct muscle imbalances between your left and right sides.
How do I perform One-Legged Leg Extension correctly?
One-Legged Leg Extension is performed in 8 steps. Start by: Sit on a leg extension machine with your back flat against the pad and knees aligned with the machine's pivot point. Adjust the shin pad to rest just above your ankles. See the full step-by-step instructions above for complete form guidance.
What type of exercise is One-Legged Leg Extension?
One-Legged Leg Extension is a strength training exercise designed to build muscle and increase force production. It primarily works the Quads.

More Quads Exercises

View All

Belt Squat

Quads
Machine

Landmine Hack Squat

QuadsGlutes+1

Equipped Squat

Quads
Barbell

Learn More

View all training guides

Let AI program your One-Legged Leg Extension

Styrki picks your One-Legged Leg Extension sets, weights and progression with adaptive periodization — and auto-detects PRs across 20+ record types. Free to track, free forever.

Get the iPhone appFree on the App Store · no credit card

Browse more exercises