Electromyographic Analysis of Back Muscle Activation During Lat Pulldown Exercise: Effects of Grip Variations and Forearm Orientation

<b>Objectives</b>: The lat pulldown machine is one of the most versatile pieces of equipment for back strengthening, allowing variations in grip and load. However, there are significant gaps in the literature regarding the relationship between exercise modality and specific muscle activation. <b>Methods</b>: This study examined the electromyographic (EMG) activity of major back muscles during seven lat pulldown exercise variants that differed in grip type, width, and trunk inclination. Forty male subjects, with at least 5 years of resistance training experience, performed five repetitions of lat pulldown exercise using 70% of their repetition maximum. Prior to the surface EMG analysis, maximal voluntary contraction (MVC) tests were performed for each muscle group analysed, specifically the latissimus dorsi, posterior deltoid, brachial biceps, middle and lower trapezium, and infraspinatus. The normalised root mean square of the EMG (NrmsEMG) activity for each muscle was recorded during full, concentric, and eccentric movements. <b>Results</b>: Multivariate analysis of variance (MANOVA) showed no significant difference in the NrmsEMG muscle activation across the different lat pulldown exercise variations (all <i>p</i> > 0.05). A significant difference was found in the posterior deltoid where the wide-pronated grip with a 30° trunk inclination showed greater EMG activation compared to the wide pronated grip (<i>p</i> = 0.011) and wide neutral grip (<i>p</i> = 0.017). <b>Conclusions</b>: These findings suggest that grip variations may not significantly alter latissimus dorsi recruitment, challenging the assumption that grip effectiveness targets this muscle. The results highlight the need for individualised approaches to exercise selection, given the variability in muscle activation patterns observed.