Whole-body biomechanical load in running-based sports: The validity of estimating ground reaction forces from segmental accelerations. Issue 6 (June 2019)

• Record Type: Journal Article
• Authors: Verheul, Jasper; Gregson, Warren; Lisboa, Paulo; Vanrenterghem, Jos; Robinson, Mark A.
• Is Part Of: Journal of science and medicine in sport. Volume 22:Issue 6(2019)
• Page Start: 716
• Page End: 722
• Publication Date: 2019-06
• Subjects: Training load monitoring -- Biomechanical loads -- Full-body segmental accelerations -- Loading characteristics -- Segment reductions; Sports sciences -- Periodicals; Sports medicine -- Periodicals; Exercise -- Physiological aspects -- Periodicals; Sports -- physiology -- Periodicals; Sports Medicine -- Periodicals; Sportgeneeskunde; 617.102705
• DOI: 10.1016/j.jsams.2018.12.007
• Languages: English
• ISSNs: 1440-2440

Abstract

Abstract: Objectives: Unlike physiological loads, the biomechanical loads of training in running-based sports are still largely unexplored. This study, therefore, aimed to assess the validity of estimating ground reaction forces (GRF), as a measure of external whole-body biomechanical loading, from segmental accelerations. Methods: Fifteen team-sport athletes performed accelerations, decelerations, 90° cuts and straight running at different speeds including sprinting. Full-body kinematics and GRF were recorded with a three-dimensional motion capture system and a single force platform respectively. GRF profiles were estimated as the sum of the product of all fifteen segmental masses and accelerations, or a reduced number of segments. Results: Errors for GRF profiles estimated from fifteen segmental accelerations were low (1–2 N kg −1 ) for low-speed running, moderate (2–3 N kg −1 ) for accelerations, 90° cuts and moderate-speed running, but very high (>4 N kg −1 ) for decelerations and high-speed running. Similarly, impulse (2.3–11.1%), impact peak (9.2–28.5%) and loading rate (20.1–42.8%) errors varied across tasks. Moreover, mean errors increased from 3.26 ± 1.72 N kg −1 to 6.76 ± 3.62 N kg −1 across tasks when the number of segments was reduced. Conclusions: Accuracy of estimated GRF profiles and loading characteristics was dependent on task, and errors substantially increased when the number of segments was reduced. Using a direct mechanical approach to estimate GRF from segmental accelerations is thus unlikely to be a valid method to assess whole-body biomechanical loading across different dynamic and high-intensity activities. Researchers and practitioners should, therefore, be very cautious when interpreting accelerations from one or several segments, as these are unlikely to accurately represent external whole-body biomechanical loads.