A comparison of manual and automatic force-onset identification methodologies and their effect on force-time characteristics in the isometric midthigh pull

Guppy, SN; Brady, CJ; Kotani, Y; Connolly, S; Comfort, P; Lake, JP; Haff, GG

Abstract

The aim of this study was to assess the agreement of three different
automated methods of identifying force-onset (40 N, 5 SDs, and 3
SDs) with manual identification, during the isometric mid-thigh pull
(IMTP). Fourteen resistance-trained participants with >6 months
experience training with the power clean volunteered to take part.
After three familiarisation sessions, the participants performed five
maximal IMTPs separated by 1 min of rest. Fixed bias was found
between 40 N and manual identification for time at force-onset. No
proportional bias was present between manual identification and
any automated threshold. Fixed bias between manual identification
and automated was present for force at onset and F150. Proportional
but not fixed bias was found for F50 between manual identification
and all automated thresholds. Small to moderate differences (Hedges
g = −0.487- −0.692) were found for F90 between all automated
thresholds and manual identification, while trivial to small differences
(Hedges g = −0.122—−0.279) were found between methods for F200
and F250. Based on these results, strength and conditioning practitioners should not use a 40 N, 5 SDs, or 3 SDs threshold interchangeably with manual identification of force-onset when analysing IMTP
force–time curve data.

Citation

Guppy, S., Brady, C., Kotani, Y., Connolly, S., Comfort, P., Lake, J., & Haff, G. (2021). A comparison of manual and automatic force-onset identification methodologies and their effect on force-time characteristics in the isometric midthigh pull. Sports Biomechanics, 1-18. https://doi.org/10.1080/14763141.2021.1974532

• Journal Article Type: Article
• Acceptance Date: Aug 25, 2021
• Online Publication Date: Sep 22, 2021
• Publication Date: Sep 22, 2021
• Deposit Date: Dec 22, 2021
• Journal: Sports Biomechanics
• Print ISSN: 1476-3141
• Electronic ISSN: 1752-6116
• Publisher: Routledge
• Pages: 1-18
• DOI: https://doi.org/10.1080/14763141.2021.1974532
• Publisher URL: https://doi.org/10.1080/14763141.2021.1974532
• Related Public URLs: https://www.tandfonline.com/loi/rspb20
• Additional Information: Additional Information : ** From Crossref journal articles via Jisc Publications Router **Journal IDs: pissn 1476-3141; eissn 1752-6116 **History: issued 22-09-2021; published_online 22-09-2021; Funders : Australian Government Research Training Program Scholarship