A-frame knees
The A-frame happens when your outside ski is on a higher edge than your inside one, so your knees drift towards each other. Skiers split on whether it is boot alignment or inside-leg timing, and the model can not tell them apart from a side view alone.
glutes working · lower back working
Muscle load
Easy, can hold all dayWorkingBurningTick: average through the turn
Tail at the finish
5%
Tip at the finish
12%
Showing: Model of your setup. your setup as it is.
The model has no two-ski view yet, so this is the side view of your stance. The two-ski front view, which is where an A-frame shows, is coming.
Shown for the default skier: 92 kg on the K2 Mindbender 89 Ti at the finish of the turn, 3 mm of boot play, groomed snow.
In an A-frame your knees move together and your feet spread apart, so your legs make the shape of the letter A when seen from the front. The outside ski is on a higher edge than the inside ski, which runs flatter or wanders.
That puts more load on the outside ski and asks more of your inside knee and inner thigh. It is common, and not always a problem. At high edge angles, some A-framing just means you have reached the limit of your range of motion.
The forum threads on this are long, and they split the same way every time. - Alignment. Your boot cuff angle, your footbed or the shape of your legs make it hard for both skis to tilt together. A fitter checks this, and a one-footed mirror test at home is a simple way to see what you want to show them. - Timing. You are leaving the old outside ski too late, or you are not tipping the new inside ski early enough. This is technique.
Both exist. A fitter can look at the first. A coach or a video can look at the second.
The model here is a side view of one skier. It can show your stance, but the A-frame is a front-view shape with two skis, and that view is not built yet. So the figure above shows the side view of your stance and the load in each muscle, and not the knees coming together. We are working on the two-ski view.
Stand in front of a mirror in your boots, bend your knees, and stand on one foot. Note whether your knee drops in on one side, and do it with both feet. It is a self-check to show your fitter, not a diagnosis.
The old advice to push your knee out with your hand rarely works. It treats the shape and not the cause.
The model’s first match for this symptom is your inside leg isn't tipping (56% of the evidence). Here is what else it ranks, and how to tell each one apart.
If the cuff angle doesn't suit your lower leg, or the shell is so tight the ankle can't roll, the inside ski can't match the outside one however good your technique.
How to tell: It happens on every turn and on both sides, however you try to fix it. That points to the cuff, footbed or shell rather than timing.
Model check: The model has no number for this one, so it rests on what you report.
If the mirror self-check shows your knee dropping in the boot, take the result to a boot fitter. A fitter checks alignment, and a drill alone may not change it.
Compare skisA-framing can load the inside knee. If you have knee pain, especially on the inside of the joint, see a physio.
Pain or injury? This tool is for how skiing feels, not medical advice. See a physio.
Not medical advice. Edge Lab describes how skiing feels and why.
The model above uses a default skier. Add your weight, skis and boots and see your own numbers.
Check your own setup