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Thoracic-worn accelerometers detect fatigue-related changes in vertical stiffness during sprinting
Horsley, Benjamin J. Tofari, Paul J. Halson, Shona L. Kemp, Justin G. Johnston, Rich D. Cormack, Stuart J.
Horsley, Benjamin J.
Tofari, Paul J.
Halson, Shona L.
Kemp, Justin G.
Johnston, Rich D.
Cormack, Stuart J.
Abstract
Horsley, BJ, Tofari, PJ, Halson, SL, Kemp, JG, Johnston, RD, and Cormack, SJ. Thoracic-worn accelerometers detect fatigue-related changes in vertical stiffness during sprinting. J Strength Cond Res 38(2): 283–289, 2024—Thoracic-mounted accelerometers are valid and reliable for analyzing gait characteristics and may provide the opportunity to assess running-related neuromuscular fatigue (NMF) during training and competition without the need for additional tests, such as a countermovement jump (CMJ). However, their sensitivity for detecting fatigue-related changes in gait across different speeds is unclear. We, therefore, assessed the changes in accelerometer-derived gait characteristics, including vertical stiffness (Kvert), following a repeated sprint protocol (RSP). Sixteen recreationally active subjects performed single and repeated CMJs on a force plate and 40 m run throughs overground at 3–4, 5–6, and 7–8 m·s−1 pre-post a 12 × 40 m RSP. Gait characteristics (contact time, step frequency, step length, Kvert, etc.) were derived from an accelerometer contained within a global navigation satellite system unit on the thoracic spine using a validated algorithm. Changes in running gait and CMJ performance were assessed using a linear mixed-effects model (95% confidence interval [95% CI]; effect size [ES]). Significance was set at p < 0.05. A significant reduction in Kvert occurred at 7–8 m·s−1 following the RSP (−8.51 kN·m−1 [−13.9, −3.11]; p = 0.007; ES [95% CI] = −0.39 [−0.62, −0.15]) which coincided with a decreased jump height (−0.03 m [−0.04, −0.01]; p = 0.002; ES [95% CI] = −0.87 [−1.41, −0.30]). However, all other gait characteristics were not significantly different irrespective of speed. Thoracic-worn accelerometers can detect changes in Kvert at 7–8 m·s−1 which may be useful for monitoring NMF during sprinting. However, a RSP does not result in altered gait mechanics in subsequent running at lower speeds.
Keywords
inertial measurement units, countermovement jump, gait analysis, global navigation satellite system, running, trunk
Date
2024
Type
Journal article
Journal
Journal of Strength and Conditioning Research
Book
Volume
38
Issue
2
Page Range
283-289
Article Number
ACU Department
School of Behavioural and Health Sciences
Faculty of Health Sciences
Faculty of Health Sciences
Relation URI
Source URL
Event URL
Open Access Status
License
All rights reserved
File Access
Controlled
Notes
© 2023 National Strength and Conditioning Association.