Leg extension

Seated in the machine, the knees straighten against the pad's load and lower slowly: the straight-leg raise's open-chain work with a weight that can be raised gradually.

Quadriceps strength family

Leg extension

Harder option

Seated in the machine, the knees straighten against the pad's load and lower slowly: the straight-leg raise's open-chain work with a weight that can be raised gradually.

DemandEasy

Equipment requiredStrength machine

Muscle focusQuads

Gets into position, then repeats the movement. Technical checks passed; qualified exercise review is pending.

Watch it bigger, and flip through similar moves, in the studio.Open in the studio

Source-researched guide. Clinical review is pending.

How to move

Sit back against the pad with the knees at the edge of the seat and the roller on the front of the lower shins.
Straighten the knees until the legs are nearly level, the thighs staying on the seat.
Lower the weight slowly back to the start.

Form cues

Choose a weight you can lower over two or three seconds.
Keep the back against the pad; no swinging.

Practice and cautions

No universal dose is assigned. Choose a manageable amount for your current capacity, leave room for controlled repetitions, and allow recovery. A clinician’s individual plan takes priority.

This is movement education, not an assessment or treatment prescription. Stop for sharp or increasing pain, dizziness, numbness or tingling; seek individual guidance for symptoms, injury or restrictions.

Add to a routine Log a session

Sources and review status

Sources support the educational description; they do not establish that this exercise is suitable for you.

AAOS OrthoInfo · Knee conditioning program (straight-leg raises, leg extensions) ↗
Cambridge University Hospitals NHS · Knee exercises (static quads first, the straight leg raise after) ↗
Free Exercise DB · alias and muscle metadata ↗
Unlicense · Free Exercise DB contributors; derived from wrkout/exercises.json. Text import; no photographs or media. · Revision f00c92c7dcf1216a928a52c3706c7ce8e2f71ed5

No variation is labeled clinically validated.

Loading movement options…

What it works

Muscles

Main: Quads.

Equipment

Strength machine

Level

Beginner. See the easier and harder options above.

Workouts that use it

Leg day workout (gym) · 55 min

Pain guides that use it

Part of a staged plan, with when to get help first.

Jumper's knee (patellar tendinopathy): a loading plan

Similar moves

Single-Leg Leg Extension demonstrated on the 3D figure

3D demoSingle-Leg Leg ExtensionBeginner · Strength machine

Back squat with bands demonstrated on the 3D figure

3D demoBack squat with bandsAdvanced · A barbell + A band

Back squat with chains demonstrated on the 3D figure

3D demoBack squat with chainsAdvanced · A barbell + Other / check instructions

Barbell Bulgarian split squat demonstrated on the 3D figure

3D demoBarbell Bulgarian split squatAdvanced · A barbell + A bench or box

Barbell hack squat demonstrated on the 3D figure

3D demoBarbell hack squatIntermediate · A barbell

Barbell lunge demonstrated on the 3D figure

3D demoBarbell lungeIntermediate · A barbell

Browse more

Questions people ask

What muscles does the Leg extension work?

Mainly the quads.

What equipment do I need for the Leg extension?

Strength machine.

Is the Leg extension good for beginners?

It is graded beginner, so it suits most people starting out. When it feels easy, try the Barbell box squat.

What is an easier alternative to the Leg extension?

Try the Straight-leg raise. Both are written steps in the same progression.

How do I make the Leg extension harder?

Progress to the Barbell box squat, or add load, range or slower lowering once your form is solid.