Biomechanical analyses of strongman exercises using inertial motion capture methods.

Abstract

Strongman is a strength-based sport where athletes compete to set personal bests and determine the strongest competitor. Unlike powerlifting and weightlifting, strongman requires athletes to lift, carry and pull heavy (and often large) objects, testing the athlete under a wide variety of loading conditions. The aim of the PhD thesis was to develop, validate and use ecologically valid motion capture methods to describe the biomechanics of experienced male and female strongman athletes undertaking previously under-assessed strongman exercises, to better inform the practices of strongman coaches and athletes and strength and conditioning coaches.From two systematic reviews (Chapter 2, Chapter 3), the yoke walk and atlas stone lift were identified as the most under-researched exercises commonly trained by strongman athletes. Limitations associated with traditional motion capture methods were suggested to partially explain the lack of biomechanical analyses performed on these exercises. Inertial motion capture (IMC) was presented as a solution to overcome many of the limitations of traditional motion capture methods. A technical summary (Chapter 5) of IMC data processing methods was used to develop an IMC approach suitable for the biomechanical analysis of strongman exercises.The validity of the devised IMC approach was assessed against an optical motion capture (OMC) system while participants performed the squat, box squat, sandbag pickup, shuffle walk and bear craw (Chapter 6). Good to unacceptable agreement with the OMC system was recorded for lower limb kinematic measures across all exercises, while good to excellent agreement was reported for spatiotemporal measures during the shuffle walk and bear crawl.The biomechanics of the yoke walk were characterised by: flexion of the hip and slight to neutral flexion of the knee at heel strike; slight to neutral extension of the hip and flexion of the knee at toe-off; and moderate hip and knee ROM (Chapter 7). During the acceleration phase, athletes used an abbreviated gait pattern to increase their stride rate. No main effect between-sex biomechanical differences were observed and few two-way interactions between sex and interval were observed.The biomechanics of the atlas stone lift were characterised by a recovery, initial grip, first pull, lap and second pull phase (Chapter 8). The initial repetitions in a series of four stones of increasing mass, were abbreviated versions of the later repetitions, which corresponded to a reduction in phase and total repetition duration. Between-sex biomechanical differences were primarily observed at the hip and were attributed to anthropometric differences in male and female athletes.As a result of this thesis, strongman coaches and strength and conditioning coaches will be better equipped with an understanding of the yoke walk and atlas stone lift required to: provide strongman athletes with recommendation on how to perform these exercises based on the technique used by experienced strongman athletes; conceptualise technique improvements for performance enhancement and injury minimisation; and prescribe the use of these exercises as a training tool for both strongman and non-strongman athletes. Researchers will be able to better direct future research into the biomechanics of strongman exercises and the development of IMC