  Ground reaction force sensing is one of the key components of gait analysis
in legged locomotion research. To measure continuous force data during
locomotion, we present a novel compound instrumented treadmill design. The
treadmill is 1.7m long, with a natural frequency of 170Hz and an adjustable
range that can be used for humans and small robots alike. Here, we present the
treadmill's design methodology and characterize it in its natural frequency,
noise behavior and real-life performance. Additionally, we apply an ISO 376
norm conform calibration procedure for all spatial force directions and center
of pressure position. We achieve a force accuracy of $\leq$5.6N for the ground
reaction forces and $\leq$13mm in center of pressure position.
