Ten seconds of smartphone video, shot from the side and from behind, turn into a report on how you move when you run: how to film it well, where to start reading it, and when to take it to a physical therapist.
- Who founded Ochy, and the injury behind the idea
- How to set up the shot: where to put the phone, who films, what pace to run
- A box with five mistakes that make the video hard to use
- The order to read the report in, from the most reliable metrics to the ones to handle with more caution
- How to fit the exercises into your week, and when to bring in a professional
Biomechanics Outside the Lab
Until a few years ago, if you wanted to know how your foot lands or how much your knee bends while you run, you had two options. A salesperson at a running specialty store, who watches you run a few strides and forms an impression by eye. Or a biomechanics lab: a room full of infrared cameras, reflective markers taped to your skin, your movement rebuilt in three dimensions. Precise, expensive, and rarely around the corner.
Ochy sits in the space between. All it needs is a ten-second video shot on your phone, from the side and from behind. The model recognizes your body frame by frame, extracts joint angles, stride timing and alignment, and compares them with a reference posture calculated for your build. In under a minute you get the report, along with exercises to work on whatever it turned up.
The idea has a specific origin. Khaldon Evans ran the 400 meters at the University of Central Missouri until a string of recurring injuries cut his career short. For years nobody could pin down the cause. Then a single visit to a lab with multi-camera motion capture revealed a flaw in his running that no clinician had caught with the naked eye, on a bill that ran into the thousands. Ochy was founded in Rennes, France, in 2021 to put within everyone’s reach what had come to him late, and at a steep price.
Evans started it with Perrine Chapot, a physical therapist who was working in a biomechanics lab at the time and now leads that side of the project, and Victor Dequidt, an engineer who has been CTO since 2022. You can see the physical therapist’s hand in the product: every item in the report leads to an exercise, because a measurement with no guidance on what to do next is of little use.
How to Film It Right
The report is only as good as the video behind it, and the phone has to stay still while you run past it. A tripod is the easiest option, but a bench, a low wall or even a water bottle to lean it against will do the job. If someone is filming for you, their only task is to keep their hands still. You need two shots: one in profile, with your body crossing the frame, and one from behind as you run away from the camera.
If you run alone, the treadmill is probably the best place for your first video. With the phone propped beside the belt, the distance stays the same for the whole clip, and nobody has to film you. It’s an option the founders themselves suggest.
Run at your easy-day pace, and resist the urge to speed up because you know you’re on camera. The report will describe the running you actually do every day, and ground contact measurements are more accurate at comfortable paces than at very slow or very fast ones. If you record with your camera app and upload the video later, set it to 60 frames per second or higher. The foot moves so quickly that with too few frames, the instant it touches down can fall between one frame and the next.
Five Mistakes That Ruin the Footage
- Panning to follow the runner. The frame stays fixed; you’re the one who crosses it.
- Cutting off feet or head. Your whole body needs to stay in the shot, head to shoes, for the entire clip.
- Leaving other runners in the scene. On a group run or in a race, the model may end up analyzing the wrong person.
- Shoes that blend into the background. The foot is the hardest part to track, and light-colored shoes against a light background make it harder to read. For the same reason, avoid shooting into the sun, which turns your legs into a dark silhouette.
- Skipping the rear view. From the side you see knee and torso; from behind, the rotation of the foot at landing and the movement of the pelvis come into view.
Reading the Report
The first screen shows a score for each part of the body, and tapping one opens explanations and exercises. Start with what the model measures best: Ochy compared it against a lab-grade motion capture system, in a study the company ran itself.
Think of a photo of someone running. The torso is sharp, while the hands and feet, which move faster than everything else, come out slightly blurred. Read the report the same way, from the center out to the extremities.
The first number to look at is cadence, meaning how many steps you take per minute. It’s the most reliable measurement in the report and the easiest to put to use. Next comes the knee seen from the side: how straight it is when your foot lands, and how much it bends as it absorbs your weight.
Torso lean is the example Evans used to explain the app, and it’s also the one you can check on your own. Pause the side-view video at mid-stance and look at the line running from your ear to your hip. If what you see matches the report, you have one more solid reference point.
Treat the ankle, the elbow and the finer timing measurements, the ones tied to the moment your foot leaves the ground, as pointers rather than verdicts. They earn their keep when you compare them over time, or when you bring them to someone who can watch you run in person.
From Exercises to the Physical Therapist
The exercises are what turn the report into something you act on. Treat them as a strength and mobility block, two or three times a week, after an easy run or on a day off from running. During your runs, don’t try to fix your form stride by stride: if you want to raise your cadence, do it in small increments.
After four to six weeks, shoot a new video under the same conditions: same place, same pace, same phone. The app keeps your previous analyses, and a clear change between two identical shoots tells you more than any single number.
It’s worth seeing a physical therapist when pain or an injury keeps coming back, when the report flags something at the foot and ankle and you want to act on it, or before making a substantial change to the way you run. Evans is upfront about it: the app isn’t meant to replace coaches and physical therapists, but to give them one more tool. You can export the report as a PDF. Bring it along with both videos, and the appointment starts a step ahead.
It took Evans years to see the flaw that kept stopping him. Today the first look takes ten seconds, and the next one is still the job of someone who can put their hands on your legs.