Assessment of grip difficulty of a smart climbing hold with increasing slope and decreasing depth

Abstract

In order to assess the grip difficulty of a curved climbing hold, an experimental hold was designed and instrumented with two force transducers. The hold's surface was restricted to steeper gradients by adding wooden panels to the wall. The more the centre of pressure on a curved hold surface moves off the wall, the steeper the surface gradient becomes and the more difficult it is to grip the hold. As the surface gradient steepens, the coefficient of friction increases, whereas contact time and forces decrease. At flatter gradients, the hand exerts a pulling force to the hold whereas at steeper gradients, the hand pushes against the hold. The latter action is only possible if the body moves dynamically in horizontal direction, by accelerating backwards. The transition from pulling to pushing occurs in the more experienced climber at a centre of pressure position of approximately 0.045 mm off the wall (34° slope), and in the less experienced climber earlier at approximately 30 mm off the wall (22° slope).