Straight Leg Raise
Demonstration photo coming soon
Part of these sets
This exercise rarely works alone. It appears in the following routines, where it is sequenced alongside the others that support it.
What it works
Primary muscles
- Quadriceps, holding the knee locked out straight
Also involved
- Hip flexors, lifting the leg
- Deep trunk muscles, stopping the lower back arching
Equipment: None. A mat or a firm bed, and an ankle weight later.
How to do it
- 1
Lie on your back with the training leg straight and the other knee bent, foot flat on the floor, which protects the lower back.
- 2
Pull the toes of the straight leg up towards you, tighten the thigh, and press the back of the knee down until the knee is completely locked out.
- 3
Keeping that lock, lift the whole leg 20 to 30 centimetres, no higher than the opposite bent knee.
- 4
Hold for two to three seconds. If the knee bends even slightly, the exercise has stopped doing its job.
- 5
Lower over three seconds and let the heel rest for a moment before the next repetition.
How much to do
3 sets of 10 repetitions each side
Daily while the knee is irritable, then 3 times a week
This is the low irritation option, because the knee never bends under load. Discomfort up to about four out of ten during the exercise is acceptable provided it settles within 24 hours.
Stop and get assessed if
Stop and get assessed if the knee will not straighten fully at all, if it swells after these sets, or if lifting the leg sends pain, pins and needles or numbness down the back of the leg, which points at the back rather than the knee.
Common mistakes
- Letting the knee bend as the leg lifts
- A bent knee hands the whole job to the hip flexors and leaves the quadriceps out of it. Set the lock first, then lift, and end the set at the repetition where you can no longer hold the lock.
- The heel rising before the knee is fully straight
- That gap is called an extension lag, and it means the quadriceps cannot yet hold the joint out. It is the exact deficit this exercise exists to fix, so work on the lock alone, five seconds at a time, before adding any lift.
- Lifting the leg too high
- Above the height of the opposite knee the movement is all hip and the lower back starts to arch. Lower and slower loads the thigh far more than higher and faster.
- Leaving the other leg flat
- Both legs straight lets the pelvis tip and the back arch as you lift, which is how a knee exercise turns into back ache. Keep the resting knee bent with the foot flat.
- Swinging the leg up quickly
- The quadriceps is being asked to hold, not to swing, and momentum removes the holding. Three seconds up, a pause, three seconds down, with the effort felt just above the kneecap.
Making it harder
- Increase the hold at the top towards ten seconds.
- Add an ankle weight of one to two kilograms and build the load gradually, because repetitions alone stop producing change once 15 are easy.
- Do them seated, straightening the leg out in front of you against the weight of the shin, which is the version that fits into a working day.
- Move on to sit to stands and wall squats once the knee tolerates bending under load. This exercise is a starting point, not a destination.
Making it easier
- Quadriceps setting alone: press the back of the knee down into the bed for five seconds, ten times, with no lift at all.
- Slide the heel along the floor rather than lifting the leg clear of it, keeping the knee locked throughout.