An experimental protocol was developed to investigate the effect of ski boot ramp angle on stability and on-hill turning kinetics. In an on-hill study, three ramp angles (2.5°, 5.5°, 8.5°) were tested by 10 experienced skiers through a giant- slalom race course, and the ground reaction forces were measured by ski-mounted force plates. As ramp angle increased, the center of pressure (COP) shifted medially and anteriorly, lateral forces increased, and three-dimensional moments increased. Qualitative inspection of the time histories of the forces and moments, and quantitative analyses of the average variables, identified two different groups of subjects:​ systematic and continuous reactors (SCRs) and inconsistent reactors (IRs). Between group analyses showed significant differences between these two groups:​ SCRs had a more medial and posterior position of the COP, higher lateral and vertical forces, lower anterior forces, and higher transverse and torsional moments. In a dynamic stability test, the same subjects were required to stand as still as possible on an unstable balance board in the different ski boot ramp angles;​ stability was measured by the movement of the COP. The two groups had significantly different postural performances:​ SCRs had a more anterior position of the COP, a larger surface area of the COP, and higher average speeds of movement of the COP.

In a separate in-depth stability analysis, 30 experienced skiers were required to stand as still as possible on an unstable surface while wearing ski boots of varying ramp angle. As ramp angle increased, COP shifted anteriorly, and knee flexion angle decreased. Overall, increasing ramp angle tended to have a negative effect on postural performance, but its effect on COP_area was different than on COP_vel, indicating that different postural strategies are affected differently by the orientation of the foot.

The effect of ramp angle on turning kinetics and stability was not consistent between all subjects. Some reacted systematically, while others showed discontinuities in their reactions. The results highlight that subject-specific differences exist, and alter the expected reactions of skiers movement to increasing ramp angle. Preliminary evidence suggests that limb length, and likely other physiological characteristics, affect skiers reactions to ramp angle.