Acute Kinetic and Kinematic Responses to Varied Loading in the Behind-the-Neck Push Jerk: Impact on Force and Power Production
(Chieh-Ying Chiang, Hsuan-Yu Lin, Yi-Chien Chiang, Chien-Chun Chang, Timothy J. Suchomel, Tzyy-Yuang Shiang)

While the influence of the load on mechanical outcomes has been investigated in weightlifting pulling derivatives, knowledge of these relationships in overhead pressing derivatives remains limited. To address this gap, this study examined the effects of varying loads on the force-time characteristics associated with peak power output in the behind-the-neck push jerk (BNPJ). Sixteen recreational male athletes were recruited and performed three repetitions of the BNPJ at 40%, 50%, 60%, 70%, and 80% of their 1RM. Mean system velocity (MSV), propulsive phase time (Time), peak force (PF), mean force (MF), peak power (PP), mean power (MP), the impulse and depth were calculated from force-time data during the propulsive phase and compared across loads. A series of one-way repeated measures analysis of variance (ANOVA) was used to compare the differences in each variable across intensities. The level of significance was set at p ≤ 0.05. Except for MSV, all variables progressively increased with loads. PF, MF, PP, MP, and the impulse were greatest at 80% 1RM with small to large significant differences between other intensities (p = 0.00–0.02, Hedge’s g = 0.26–2.49). There were no significant differences between 70% and 80% 1RM in PV (p = 0.35, g = 0.18), but there were significant differences between 80% 1RM and 40%, 50%, and 60% 1RM (p = 0.01–0.05, g = 0.14–0.64). Prescribing the BNPJ at 80% 1RM is beneficial in enhancing power and force output.