A big step up means stepping onto a high box or block, about knee height, and using the front leg alone to lift your whole body up. The back leg should leave the floor without pushing, so the front thigh and buttock do all the work. In the video she keeps her hands on her hips, rises onto the box, holds her balance on the front leg for a few seconds with the back foot hovering beside it, and then steps back down. It is a harder version of the ordinary step up, and it needs good control on a low step first.

How to do the big step up

Set a solid box or sturdy platform in front of you, no higher than your knee, with a wall, rail or counter beside it to touch. Start lower if a knee-high box is new to you.
Stand tall with your hands on your hips. Lift one knee and place that whole foot flat on the box, heel included.
Lean your chest a little forward over the front foot. Press that foot into the box and drive up until the leg is straight, letting the back foot leave the floor without pushing off, so it hangs in the air as you rise.
Bring the back foot up beside the front one, but keep it just off the box, or let only its toes rest lightly on it. Stand tall and hold your balance on the front leg for a moment.
Step down with the free foot first, lowering it slowly to the floor behind you while the leg on the box bends to control the drop. Then bring the other foot down beside it.
Lead with the other leg on the next rep, or finish your set on one side and then switch, as your program says.

What you should feel

Hard work in the front of the thigh and the buttock of the leg on the box, far more than on a normal stair. You may also feel your ankle and hip making small corrections as you steady yourself at the top.

Common mistakes

Springing off the back foot, so the floor leg does part of the lift.
Using a box so high that you lurch forward or swing your arms to get up.
The front knee caving in toward the other leg as you rise.
Letting yourself drop off the box rather than lowering slowly.

How often

Many programs begin with 1 to 3 sets of 5 to 8 step ups on each leg, resting between sets, with the box at a height you can control. Your physio will adjust this.

Stop and check with your physio if

Your knee buckles, or you get sharp pain in the knee, hip or ankle.
Kneecap pain that gets worse with every step up.
You feel dizzy, lightheaded, faint or sick, or the room seems to spin. Hold your support, sit down and get medical advice the same day before you practice again. If you faint, it does not settle within a few minutes of sitting still, your vision suddenly blurs or goes double, or you cannot stand or walk steadily, call emergency services.
You lose your balance on top of the box and need the support to stop a fall. Step down and rest.
Chest pain or pressure, dizziness or feeling faint, a racing or irregular heartbeat, or being far more out of breath than the effort should cause.

From the clinic

Push the box against a wall so it cannot slide, with a rail, counter or wall at your side to touch as you rise and as you come down. In the video she has nothing to hold. At home, keep a support within reach and clear the floor around the box.

Wear flat shoes that fit well and grip the floor, not socks, tights or bare feet. Anyone who has fallen within the last year, or feels unsteady on stairs or on one leg, should stay with a low step for now and ask their physio before trying this height. If you are pregnant, check with your midwife or physio before you start.

A sudden loss of balance is different. Call emergency services straight away for any sign of a stroke, even if it goes away: sudden dizziness with unsteadiness or falling over, a face that droops on one side, an arm you cannot lift or keep up, slurred or muddled speech, weakness or numbness on one side of your body or face, sudden blurred vision, double vision or loss of sight, or a sudden severe headache.

Lifting your whole body up a knee-high step raises your heart rate more than a normal stair does. With a heart condition or high blood pressure, check with your doctor before you start. If you have high blood pressure, breathe steadily through every repetition and never hold your breath. If chest pain, pressure or tightness does not ease quickly when you rest, spreads to your arm, neck, jaw, stomach or back, or comes with sweating, feeling sick, feeling light-headed or being short of breath, call emergency services straight away, as this can be a heart attack. If it eases quickly and none of these happen, get medical advice the same day, and do not exercise again until you have been checked.

If you have had a hip replacement, get the go-ahead from your surgeon or physio before you try the big step up. Placing your foot on a knee-high box and leaning forward to rise bends the hip past a right angle, and many surgeons ask you to avoid that for the first months after some operations. After a knee fracture or knee surgery, including a knee replacement, follow your surgeon's or physio's plan, and start this exercise only when they have cleared you. After an ankle fracture or ankle surgery, follow your surgeon's or physio's weight-bearing plan, and start this exercise only when they have cleared you.

Get the ordinary step up smooth on a low step first, then raise the height a little at a time. Stair climbing and step up and over are other ways your physio may build up step work.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-28.

This page is general education, not a diagnosis or a personal treatment plan. If you have pain, an injury or a health condition, see a physiotherapist or doctor before starting new exercises.

Big step up