Seated knee extension (chair)

Sitting tall on a chair, you straighten one knee against an ankle weight or a band, then lower it slowly: thigh strength with no balance demand, so it suits older adults and a flared-up knee.

Quadriceps strength family

Seated knee extension (chair)

Standard option

Sitting tall on a chair, you straighten one knee against an ankle weight or a band, then lower it slowly: thigh strength with no balance demand, so it suits older adults and a flared-up knee.

DemandEasy

Equipment requiredA bench or box + Something with weight

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 tall on a firm chair with your back supported and your thighs fully on the seat. Add an ankle weight, or loop a band from the chair leg to your ankle.
Tighten the front of the thigh and straighten the knee over 2 to 3 seconds.
Pause briefly near straight. With pain around the kneecap, stop at about halfway (the knee still bent about 45°) for the first weeks.
Lower over about 3 seconds.
Finish the set, then switch legs.

Form cues

Lift slowly and lower more slowly.
Keep your back against the chair.
Avoid: swinging the leg, leaning back to help the lift, or starting too heavy.

Practice and cautions

3 sets of 10 to 15 each leg, 2 to 3 days a week. An editorial starting point: this exact move has not been tested on its own, though quadriceps-focused programmes showed larger effects in knee arthritis trials.

If the full range hurts, work only in the bent-knee half, from 90° to about 45°: in a lab study that range loaded the kneecap joint least. 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.

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Sources and review status

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

No variation is labeled clinically validated.

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What it works

Muscles

Main: Quads.

Equipment

A bench or box + Something with weight

Level

Beginner. See the easier and harder options above.

Pain guides that use it

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

Similar moves

Sit to stand from a chair demonstrated on the 3D figure

3D demoSit to stand from a chairBeginner · A bench or box

Captain's chair knee raise demonstrated on the 3D figure

3D demoCaptain's chair knee raiseIntermediate · Other / check instructions

Horizontal back extension (hyperextension, Roman chair) demonstrated on the 3D figure

3D demoHorizontal back extension (hyperextension, Roman chair)Advanced · A bench or box

Single-Leg Leg Extension demonstrated on the 3D figure

3D demoSingle-Leg Leg ExtensionBeginner · Strength machine

Step-up with knee raise demonstrated on the 3D figure

3D demoStep-up with knee raiseIntermediate · A step

Bodyweight squat demonstrated on the 3D figure

3D demoBodyweight squatBeginner · No equipment

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Questions people ask

What muscles does the Seated knee extension (chair) work?

Mainly the quads.

What equipment do I need for the Seated knee extension (chair)?

A bench or box + Something with weight.

Is the Seated knee extension (chair) good for beginners?

It is graded beginner, so it suits most people starting out. When it feels easy, try the Leg extension.

What is an easier alternative to the Seated knee extension (chair)?

Try the Quad set (static quads). Both are written steps in the same progression.

How do I make the Seated knee extension (chair) harder?

Progress to the Leg extension, or add load, range or slower lowering once your form is solid.