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Knee fold

Lying on your back with the knees bent, one foot lifts and the knee floats up to a right angle while the pelvis stays still, then lowers: the first step towards the dead bug, from postnatal physiotherapy and Pilates. The other foot stays on the floor throughout.

Movement guide

Knee fold

DemandEasy
Equipment requiredFloor space
Muscle focusAbs · Hip flexors

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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

Make it easier or harder

Start where you can move well, then step up.

Easier option

Supine heel slide demonstrated on the 3D figure3D demoSupine heel slideBeginner · No equipment

Suggested next step, beginner grade.

Harder option

Dead bug heel taps demonstrated on the 3D figure3D demoDead bug heel tapsBeginner · No equipment

Suggested next step, beginner grade.

Source-researched guide. Clinical review is pending.

How to move

  1. Lie on your back with your knees bent, feet flat and hip-width apart, and your arms by your sides.
  2. Breathe in. As you breathe out, gently draw up your pelvic floor and lower tummy.
  3. Lift one foot a few centimetres and float the knee up until the hip is bent to about a right angle, keeping the pelvis still.
  4. Hold for a short count, breathing.
  5. Lower the foot slowly to the floor, relax, and repeat on the other side.

Form cues

  • Keep the low back and pelvis still; only the leg moves.
  • Breathe out as the knee floats up.
  • Avoid: letting the middle of your tummy bulge into a ridge; if it does, lift the foot only a little.

Practice and cautions

2 sets of 5 to 10 each side, every other day: the dose a UK pelvic health physiotherapy booklet (POGP) gives for alternate knee bends. A standard early postnatal and Pilates step; no trial has tested it on its own.

After a caesarean, start once lifting a leg doesn't pull on the wound. In pregnancy after the first trimester, do it propped up on pillows. 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.

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.

What it works

Muscles

Main: Abs. Also: Hip flexors.

Anatomy: Rectus abdominis, Obliques, Transversus abdominis.

Equipment

None: body weight and floor space.

Level

Beginner. See the easier and harder options above.

Workouts that use it

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Questions people ask

What muscles does the Knee fold work?

Mainly the abs, with help from the hip flexors.

What equipment do I need for the Knee fold?

No equipment: your body weight and a little floor space.

Is the Knee fold good for beginners?

It is graded beginner, so it suits most people starting out. When it feels easy, try the Dead bug heel taps.

What is an easier alternative to the Knee fold?

Try the Supine heel slide. It is the suggested step down from this move.

How do I make the Knee fold harder?

Progress to the Dead bug heel taps, or add load, range or slower lowering once your form is solid.