Fig. 2

Illustration of the computation of the range of motion. a The motion of a single arm from a backward position to a forward position. The range of motion is defined as the difference, \(\Delta _{\theta }\), in the estimated angle \(\theta\) between the final points of consecutive forward and backward swings of the same arm. b An example of the estimated angle in degrees (deg) of a single time window, with detected peaks marked in red. The range of motion is calculated as the absolute difference between consecutive peaks