Session: 05-11-01: Musculoskeletal and Sports Biomechanics I

Paper Number: 67624

Start Time: Friday, 01:15 PM

67624 - Preliminary Study: Development of Sport Climbing Hold Measurement System for Performance Analysis 

INTRODUCTION: Sport climbing participation has increased to over 35 million people worldwide in recent years. According to the Climbing Business Journal, it grew at a rate of 6.9 percent in 2016, 10 percent in 2017, and 11.8 percent in 2018, and is becoming more popular with its debut at the next Olympic Games in Tokyo. In spite of this growth in popularity, even elite climbers have limited options to assess their performance and understand their weaknesses, as coaches can only observe an athlete’s movements but do not have quantitative information about the interaction between the climbing hold and the climber’s body [1]. Moreover, new climbers do not typically have access to a coach and thus climb without feedback on technique since their only goal is to reach the top. 

PURPOSE: This paper discusses preliminary results for the development of a measurement system that provides quantitative feedback and information on various parameters for climbing, with the hope of creating a tool to improve sport climbing performance.

PRIOR WORK: Studies have been conducted by others to observe which parameters distinguish between elite and sub-elite climbers and have measured differences between climbers [1-3]. Previous researchers have also developed lab-use instrumented climbing holds to observe specific parameters in constrained environments. While their outcomes provide important information, these systems require changes to the climbing wall and/or the hold, limiting their potential use with existing climbing wall systems. Additionally, these lab-use holds have been expensive and thus impractical to cover an entire climbing route [1].

METHODS: Consequently, this research’s objective is to develop an inexpensive, instrumented climbing system that can be used with standard, off-the-shelf holds and can be installed on existing climbing walls. Such a system would not distract climbers whilst acquiring climbing parameters. The long-term aim is to design a measuring system capable of detecting parameters such as contact time, force in three dimensions (vertical loading, out of the plane force, and lateral forces), a measure of roughness with fractal dimensions, centre of pressure, and friction coefficient. These parameters are recognised as significant for determining climbers’ performance [2].

 
RESULTS: An instrumented climbing hold mounting screw was designed to measure vertical loading on the hold. Bending moment theory was used to determine what the expected output load should be. The experimental measuring system comprised a standard climbing hold, a modified socket head cap screw, and strain gauges bonded on the shank of the screw. With a resolution of 10 N, the data acquisition system consisted of a strain completion module and a 24-bit A2D converter with a 10 Hz sampling rate. Two strain gauges were bonded to the screw’s shank in a Wheatstone bridge configuration to compensate for temperature effects and noise due to cable length. Changes in strain on the screw were calibrated by applying different weights to the climbing hold mounted on a test wall. The aim was to have high sensitivity of the system to detect subtle changes in loads on the hold, and a sensitivity of 10 N was found to be sufficient. The results from testing also correlated well with theory.

CONCLUSIONS: In summary, the preliminary instrumented mounting screw was evaluated with a comparison between the analytical and experimental values of strain. Experimental output data coincided with theoretical calculations. Linear correlation was observed between weights applied to the climbing hold and strain changes of the mounting screw. Results showed that strain gauges bonded on a screw can detect vertical load applied to the climbing hold, and the obtained results are adequate for detecting contact time and vertical force, as well as roughness with fractal dimensions. However, to define other parameters, 1) forces in the other directions (out-of-the-wall and sideways), 2) centre of pressure, and 3) friction coefficient, additional experiments with sensors interfacing with the mounting screw will be carried out.
 

Presenting Author: Nina Pernus University of Canterbury

Authors:

Nina Pernus University of Canterbury
Deborah Munro University of Canterbury