Stiff ankles and vertical jump: why mobility is holding you back

The point, in two lines

If your ankle doesn't bend forward enough, your knee can't travel out over your foot. The loading gets shorter, the drive starts from a higher and shorter position, and you lose centimeters before you've even pushed.

It's one of the most annoying limits because you can't see it. You can have strong legs, decent squats, plyometrics in order — and still jump the same, because at some point the ankle says no.

What the ankle actually does when you jump

When you load up before takeoff, three joints bend together: hip, knee and ankle. The ankle bends into dorsiflexion — the shin tips forward over the foot while the heel stays down.

If that movement is limited, two things happen, both bad:

• You load less. The body stops earlier, your center of mass drops less, the approach produces less.
• You compensate somewhere else. The heel lifts off the floor, the knee caves in, the back bends more. The jump still comes out, but it costs more in load on knees and lower back.

In volleyball this hits hardest on the last step of the approach, where you have to absorb a lot of horizontal speed in very little time. In basketball you feel it on the second jump, when you have to reload right away without time to set yourself.

How to tell if you're stiff (no equipment)

The simplest test is the wall test. Kneel in front of a wall with one foot forward and try to touch the wall with your knee while keeping your heel glued to the floor. Then move the foot back until you can't reach it anymore.

You don't need an exact number. You need to answer three questions:

• Does my heel lift as soon as I push the knee forward?
• Do the right and left ankles behave the same way?
• Do I feel a block at the front of the ankle, like bone on bone, or a pull behind, in the calf?

That third answer changes the work. A pull behind is tissue: short calf and posterior chain. A hard block at the front is more often joint-related, and often it's the memory of an old sprain. If you've had serious sprains and the ankle keeps locking up or giving way, this isn't article material: go see a physiotherapist.

Compare right and left too. A marked asymmetry explains quite a few things, like why you take off better on one side.

What to do, in order of priority

1. Work on the ankle first, then on the jump

Mobility belongs where the body is warm and receptive: in the warm-up, before the explosive part. A few minutes, slow and controlled movements, heel staying down. It's not 30 seconds of passive stretching tossed in at the end of the session.

2. Get strong in the new range

Gaining degrees and not using them is pointless. After the mobility work, add something that asks the ankle to work while bent: lunges where the knee really travels forward, squats with the heel on the floor, full calf raises. The range you don't train is the range you don't keep.

3. Don't neglect the calf

A short, weak calf limits dorsiflexion and doesn't hold up during takeoff. If you want to understand how much this area really matters, we covered it in a dedicated piece.

4. Then go back to the jump

Once the ankle lets you load, plyometrics become more useful because they start from a better position. Measure first, then work, then measure again: without that first number you don't know whether you're getting anywhere.

A mistake we see a lot

People who find out their ankles are stiff throw themselves into twenty minutes of mobility a day and take that time away from strength. It doesn't work that way. Mobility is a permit, not an engine: it opens up the position, but the centimeters come from strength and from being able to express it fast. Five minutes done well every day is worth more than half an hour on Sunday.

How to measure whether anything is changing

Two reference points, not one:

• The wall test, always under the same conditions, to see whether the ankle is opening up.
• Your measured jump, to see whether that opening has turned into drive.

You can gain mobility and not gain jump: that means the limit was somewhere else. And that's still information that saves you months.

The free JHP tool calculates your jump height from flight time: you upload a two-second video, the analysis runs in your browser and the video never leaves your phone.

You might also like:

• Calves and vertical jump: how much they really matter
• Why your vertical jump has stopped improving: 6 reasons