## 4 Discussion
Combining the grip width in the two forearm positions, [PERSON] [23] showed no influence on electrical activation, specifically in the clavicular portion of the pectoralis major. This author points out the lack of knowledge about the reason why the clavicular portion of the pectoralis major increases its activity when the forearm is supinated. While activation is an important factor to consider, there is also a need to consider the risk of injury associated with different types of grip. Multiple studies have demonstrated that using a grip equal to or greater than 200% BAD results in increased shoulder abduction, with angles approaching 90 degrees that can potentially be harmful to the glenohumeral joint. Additionally, performing this exercise with such a grip increases the likelihood of both chronic and acute injuries due to its high volume and common use in training [70; 71; 72; 73; 74; 75]. Similarly, a narrow grip could produce a tendency for the elbow to rotate in the mid-plane, increasing the risk of injury [67]. Therefore, along with the results of this meta-analysis, a grip greater than 100% BAD and less than 200% BAD will maintain a similar activation of the pectoralis major, in addition to reducing the risk of injury by reducing abduction at an angle, approximately 45\({}^{\circ}\), in this grip width [73]. These factors may indicate the proper grip type to generate sufficient muscle activation to obtain hypertrophy, increase muscle strength, and prevent injuries. The pectoralis muscle activation was compared between different inclination benches. The concept has been created that a greater inclination in the BP means a greater incidence with respect to the activation of the clavicular portion of the pectoralis major, as opposed to a detriment of the sternal portion [67]. In relation to the declined variant, the meta-analysis showed that the declined BP shown significantly less clavicular portion activation and high sternal portion activation than horizontal BP [35; 50; 53]. These results are in line of results of previous research, such as those of [PERSON] et al. [66], that showed significant differences in favor of the sternal pectoral and other studies that showed similar levels of activation [50; 53; 69]. In this question [PERSON] et al. [66] only found significant differences in the grip of 200% BAD, while with a narrow grip of 100% BAD they did not find this significance, so we must take into consideration the results of [PERSON] et al. [69], since it presents the same with the average of different widths of grip, thus being able to be influenced. The inclined variant of the BP indicated significantly less activation of the sternal portion compared to the horizontal BP [35; 50; 53]. These data are in line with the findings of several authors where they showed a detrimental effect on the activation of the sternal portion as the slope increased [50; 66; 74; 75]. In contrast, the clavicular portion showed no significance against the significant results found by [PERSON] et al. [50], and [PERSON] et al. [53] found specifically only during 26 to 50% of the contraction movement, therefore it is important to analyze each of the variations in the different times of the movement. On the other hand, in relation to the results of this meta-analysis, [PERSON] et al. [66], found no difference in the clavicular portion with respect to the execution of an inclined and horizontal press. In the same line, [PERSON] et al. [69], did not observe differences in the activation, although it is necessary to consider the angle of inclination (25\({}^{\circ}\)), which is inferior to the rest of articles [35; 50; 53]. It is possible to mark a minimum range of inclination to be able to influence in a superfluous way in the clavicular portion, although it should also be taken into consideration that angles greater than 45\({}^{\circ}\) can cause the opposite effect and decrease the involvement of the pectoralis major [76].