Content Validity Index and Reliability of a New Protocol for Evaluation of Lifting Technique in the Powerlifting Squat and Deadlift.

Abstract

Sjöberg, H, Aasa, U, Rosengren, M, and Berglund, L. Content validity index and reliability of a new protocol for evaluation of lifting technique in the powerlifting squat and deadlift. J Strength Cond Res 34(9): 2528-2536, 2020-The aim of the study was to create a protocol to cover aspects of technique considered to be associated with risk of injury in the powerlifting squat and deadlift and to examine the content validity and reliability of the aspects included in the protocols. For the content validity investigation, a consensus group of 3 powerlifting physiotherapists identified the domains of content (risk of injury) for 2 protocols (1 for squat and 1 for deadlift) of essential aspects of lifting technique through discussions and a review of the literature. Eight selected powerlifting experts rated the relevance of each aspect in relation to risk of injury (acute or by overuse), and a quantitative estimate of the content validity of each aspect was measured through calculations of a Content Validity Index (CVI). Aspects of low content validity were discarded, and the remainders were evaluated for their inter-rater and intra-rater reliability among 4 experienced powerlifters used to coaching and evaluating powerlifting technique. The reliability was calculated and analyzed with kappa and percentage of agreement. The final protocols included 17 aspects of squat technique and 10 aspects of deadlift technique that showed good to excellent CVI and percentage of agreement between 64 and 100%. The protocols, formed in this study, will provide evidence-based recommendations on safe lifting technique for coaches and strength practitioners' to use to make relevant assessments and instructions.