Biceps Brachii and Brachioradialis Excitation in Biceps Curl Exercise: Different Handgrips, Different Synergy

Abstract

The current study analyzed the excitation of biceps brachii, brachioradialis, and anterior deltoid during bilateral biceps curl performed with different handgrips. Ten competitive bodybuilders performed bilateral biceps curl in non-exhaustive 6-rep sets using 8-RM with the forearm in supinated, pronated, and neutral positions. The ascending and descending phase of each variation was separately analyzed using the normalized root mean square collected using surface electromyography. During the ascending phase, (i) biceps brachii excitation was greater with the supinated compared to the pronated [+19(7)%, ES: 2.60] and neutral handgrip [+12(9)%, ES: 1.24], (ii) the brachioradialis showed greater excitation with the supinated compared to the pronated [+5(4)%, ES: 1.01] and neutral handgrip [+6(5)%, ES: 1.10], (iii) the anterior deltoid excitation was greater with the pronated and neutral handgrip compared to the supinated condition [+6(3)% and +9(2)%, ES: 2.07 and 3.18, respectively]. During the descending phase, the anterior deltoid showed greater excitation in the pronated compared to the supinated handgrip [+5(4)%, ES: 1.02]. Changing the handgrips when performing biceps curl induces specific variations in biceps brachii and brachioradialis excitation and requires different anterior deltoid interventions for stabilizing the humeral head. Practitioners should consider including different handgrips in the biceps curl routine to vary the neural and mechanical stimuli.

Investigating the biomechanics of the biceps brachii muscle during dumbbell curl exercise: A comprehensive approach

“…Finally, the study revealed that there is a linear correlation between resistance and muscle fatigue [39]. Coratella et al (2023) investigated the impact of different handgrip positions on the activation of the BB and brachioradialis muscles during dumbbell curl exercises. EMG measurements in 10 resistance-trained male subjects revealed that the supinated grip resulted in higher BB activation, while the pronated grip yielded greater brachioradialis activation [40].…”

“…Coratella et al (2023) investigated the impact of different handgrip positions on the activation of the BB and brachioradialis muscles during dumbbell curl exercises. EMG measurements in 10 resistance-trained male subjects revealed that the supinated grip resulted in higher BB activation, while the pronated grip yielded greater brachioradialis activation [40]. Typically, the techniques utilized for investigating the mechanical behavior of the BB muscle are contingent upon the particular kind of physical information that researchers seek to acquire.…”