Muscle activity during the incline shoulder press in relation to the exercise intensity

Katarzyna Stronska,Adam Maszczyk,Adam Zajac,Paulina Bojacz,Petr Stastny,Artur Golas

doi:10.5507/ag.2018.019

Abstract

Background: The incline machine shoulder press (IMSP) is an alternative resistance exercise to the bench press associated with throwing performance. The muscle activity during IMSP has not yet been described in females and at different exercises intensities. Objectives: The aim of this present study was to investigate changes in the activity of prime movers during the IMSP in relation to the exercise intensity in female athletes. Methods: Eight female athletes experienced in resistance training were screened for peak electromyography amplitude normalized for maximum voluntary isometric contraction during the IMSP with increasing loads of 40%, 60%, 80% and 100% of 1 repetition maximum (1RM). The selected muscles were the anterior deltoid (AD), pectoralis major (PM), triceps brachii long head (TBlong) and triceps brachii lateral head (TBlat). Results: The results of Friedman ANOVA showed increased muscle activity along with exercise intensity in all prime movers (p < .001). The Kruskal-Wallis ANOVA showed inter-muscle differences at exercise intensity of 40% 1RM (p = .004, ηp2 = .52), 60% 1RM (p = .005, ηp2 = .55), 80% 1RM (p = .035, ηp2 = .46) and 100% 1RM (p = .002, ηp2 = .52), where TBlat showed lower activity than other muscle groups at each exercise intensity. The TBlong showed lower activity than the PM and AD at 40% 1RM, and the PM activity was lower than that of AD and TBlong at 100% 1RM. Conclusions: The IMSP is an exercise which activated AD and TBlong more than PM and TBlat during maximal lifting effort. Therefore, the IMSP should be understood as the exercise which might substantially overload the AD and TBlong during maximal lifts. Coaches should use the IMSP if they desire to activate TBlong more than TBlat during upper limb pressing.

Highlights

In modern sports, one of the main elements of the training process is the analysis of fundamental movement patterns as a basis for development of the athlete’s strength abilities
Gender and movement technique, the muscular activity patterns vary during the upper limb pressing exercises, yet most research confirms that three muscle groups are involved as prime movers in upper limb pressing exercises: pectoralis major (PM), anterior deltoid (AD) and triceps brachii (TB) (Gołaś, Maszczyk, Pietraszewski, et al, 2018; Gołaś et al, 2017; Król & Gołaś, 2017; Stastny et al, 2017)
In triceps brachii lateral head (TBlat) post hoc test showed differences between the 40% of 1 repetition maximum (1RM) compared to 80% 1RM, 40% of 1RM compared to 100% 1RM, 60% of 1RM compared to 80% of 1RM and between 80% of 1RM compared to 100% 1RM

Summary

Introduction

One of the main elements of the training process is the analysis of fundamental movement patterns as a basis for development of the athlete’s strength abilities. Knowledge of muscle activity during the upper limb pressing movements can help determine which exercise variations are effective for increasing an athlete’s performance or neuromuscular adaptation, and which variation can strengthen or overload specific muscles during training, therapy or reconditioning. Studies on BP variations are well described in terms of exercise intensity, speed of movement, training method (Stastny et al, 2017) and grip variations (Barnett et al, 1995; Lehman, 2005), the studies on the shoulder press, including the incline machine shoulder press (IMSP) are scarce. The muscle activity during IMSP has not yet been described in females and at different exercises intensities. Results: The results of Friedman ANOVA showed increased muscle activity along with exercise intensity in all prime movers (p < .001). Coaches should use the IMSP if they desire to activate TBlong more than TBlat during upper limb pressing

Objectives

Methods

Results

Conclusion