Figure 4.

Loss of balance experienced by participant #2, with voice annotation, “Activity for the last hour and half or so. Got to our cottage, about 2-3 feet snow in the driveway. Probably 100-150 foot walk from the car on the road to the house in numerous trips, probably a lot of slip and slide.” (left) Data from IMUs. (right) Reconstructed body motions. The event starts with a faulty step of the right foot, shown as an unusual slow, sideways step. It is followed by a quick compensatory left foot step. See also the animation in supplementary material.