Back knee at contact
What your back leg is doing as the other foot lands
While one foot touches down, the back leg is already coming forward. Runify Motion measures how bent it is at that instant: it shows how you bring the leg back through.
Approximate measure: it has a score, but the app reads it with caution and doesn’t suggest exercises.
Opposite contact: the back leg as the other foot touches down
How to read the value
0° is a straight leg; the higher the value, the more tightly the back leg is folded.
More flexion doesn’t mean better: that’s one more reason the value depends on speed and the app reads it with caution.
It’s an approximate measure: the card says “Approximate · The back leg is often the one far from the camera, hidden by the other.”
What it can mean
It describes how the back leg is coming forward at the moment of foot contact. It’s often the leg far from the camera, hidden by the other: the value is approximate.
Running studies rarely report this measure as a number: that’s why the app doesn’t use it to suggest exercises.
To measure it well
To measure the other leg too, record a second clip running in the opposite direction.
The moment your foot touches down is very short: record at 60 frames per second or more. Below 60 fps the app flags it and the values at contact become approximate.
What the app suggests
Nothing to try: this measure is approximate, and no gait retraining backed by studies exists to change it.