Validity and Reliability of a Portable Isometric Mid-Thigh Clean PullJames, Lachlan P.1; Roberts, Llion A.1; Haff, G. Gregory2; Kelly, Vincent G.1,3; Beckman, Emma M.1Journal of Strength & Conditioning Research: May 2017 - Volume 31 - Issue 5 - p 1378–1386 doi: 10.1519/JSC.0000000000001201 Technical Report Abstract Author Information Abstract: James, LP, Roberts, LA, Haff, GG, Kelly, VG, and Beckman, EM. Validity and reliability of a portable isometric mid-thigh clean pull. J Strength Cond Res 31(5): 1378–1386, 2017—This study investigated the test-retest reliability and criterion validity of force-time curve variables collected through a portable isometric mid-thigh clean pull (IMTP) device equipped with a single-axial load cell. Fifteen males with ≥6 months of resistance training experience attended two testing sessions. In each session, participants performed an IMTP in 2 separate conditions in a randomized counterbalanced manner. The criterion condition consisted of a closed-chain IMTP configured with a force plate (IMTPf), whereas the experimental test was undertaken using a portable IMTP with data acquired through a single-axial load cell (IMTPl). A very high reliability (coefficient of variation [CV] = 3.10, 90% confidence interval [CI]: 2.4–4.6%; intraclass correlation coefficient [ICC] = 0.96, 90% CI: 0.90–0.98) and acceptable validity (CV = 9.2, 90% CI: 7–14%; ICC = 0.88, 90% CI: 0.71–0.95) were found in the experimental condition for the measure of peak force. However, significant differences were present between the IMTPf and IMTPl (p < 0.0001). Alternate force-time curve variables did not reach acceptable levels of validity or reliability in the experimental condition. The IMTPl is a valid and highly reliable method for assessing peak force. This provides evidence supporting the use of an IMTPl as a cost-effective and portable alternative for those who wish to assess maximal force production in a similar fashion to a traditional IMTP. However, practitioners should be aware that these are slightly different tests. 1School of Human Movement and Nutrition Sciences, University of Queensland, Queensland, Australia; 2Center for Sport and Exercise Science Research, Edith Cowan University, Perth, Australia; and 3Brisbane Broncos Rugby League Football Club, Queensland, Australia Address correspondence to Lachlan P. James, firstname.lastname@example.org. Copyright © 2017 by the National Strength & Conditioning Association.