Quantification of the Grip Difficulty of a Climbing Hold (P142)

Abstract

The difficulty of a climbing hold was attempted to be quantified based on fractal dimensions. The difficulty was confined to the change of a single value, namely the inclination of the grip surface, by increasing the overhang of the wall. Sixteen climbers of different experience levels participated in this experiment and had to climb a route equipped with an instrumented hold repeatedly until they failed at a specific degree of overhang. The force-time signals served to calculate the Hausdorff dimension. Subsequently, the Hausdorff dimension was normalised to force and time by a power fit. The normalised Hausdorff dimension increases significantly with the difficulty of a climbing hold, which is — in this study — the inclination of the grip surface. Weaker climbers produced larger normalised Hausdorff dimensions. If the climber fails at the instrumented hold, the force-time signal shows smaller normalised Hausdorff dimensions. Fractal dimensions are a suitable tool to quantify the difficulty of a hold if applied with caution.