The motion of thrusting upon a partners leg which is defined by three corresponding elements of:
A. Position
B. Intensity
C. Range
A. In a crouched position, with hand supporting lean, helping you drive you pelvic region against your partners appendage.
B. This entails the speed at which you are thrusting in such "humping" motion.
C. The length of trajectory from furthest point to contact between genitals and leg.
Please note: Low level dry humping and the action of grinding are similar but different.
"I don't like to dance at clubs, because my attempt at grinding always turns into low level dry humping."