The effects of the conventional deadlift and Romanian deadlift on muscle activation and joint angles at a submaximal intensity

Abstract

In strength and conditioning, exercise selection and intensity are pivotal for designing resistance training programmes. The conventional deadlift (CD) and Romanian deadlift (RDL) are exercises targeting the lower limbs. Despite being similar, differences exist and comparative studies between CD and RDL remain scarce. This study (i) assessed if the biceps femoris (BF) exhibited greater activation during the RDL, and (ii) determined if the vastus lateralis (VL) and BF showed increased activation during the CD. Fifteen active adults participated in the study, with EMG sensors placed on the VL and BF and markers for 2D motion analysis in the sagittal plane. Maximal voluntary contraction (MVC) data were collected for both lifts at 70% of the RDL 1RM. Five repetitions at 50% of the RDL 1RM were tested for EMG and 2D motion analysis. Data were analysed using paired t-tests and Wilcoxon signed-rank tests. Results revealed higher VL activation in the CD (P < 0.05), with no significant difference in BF activation. No differences were observed in hip angles at mid-thigh and knee height (P > 0.343), but differences were noted at the bottom position. Knee angles differed significantly during ascent and descent at mid-thigh (P < 0.027), while ankle differences were evident at knee height and the bottom position (P < 0.12). Ranges of motion differed for all joints (P < 0.002). In conclusion, this study found no difference in BF activation but greater VL activation during the CD.