Figure 1. The Actigraph GT3X accelerometer measures movement on three axes

From

Physical Intensity of Movement along Horizontal, Vertical, and Lateral Climbing Planes

Buddy R. Woodman, Kirk E. Mathias, James De Paepe, Michelle Adler, Brian Mc Gladrey

Journal of Physical Activity Research. 2018, 3(2), 125-130 doi:10.12691/jpar-3-2-10