Shoulder Kinematics and Symmetry at Different Load Intensities during Bench Press Exercise

oleh: Juan Manuel Franco-García, Miguel Rodal, Rafael Gutiérrez-Horrillo, Jorge Carlos-Vivas, Jorge Pérez-Gómez, Hadi Nobari, Luca Paolo Ardigò, Konstantinos Gianikellis

Format: Article
Diterbitkan: MDPI AG 2021-10-01

Deskripsi

This study aimed to analyze between-shoulder kinematics symmetry at different load intensities considering full range of movement (ROM), mean and maximum velocities (V<sub>MEAN</sub>, V<sub>MAX</sub>), and accelerations (A<sub>MEAN</sub>, A<sub>MAX</sub>) of shoulders during phases 2 (characterized by positive acceleration and negative velocity, eccentric) and 3 (characterized by positive acceleration and velocity, concentric) of bench press exercise (BP); as well as to compare unilateral kinematics variables between the different load intensity intervals. Twenty-seven participants were evaluated during phases 2 and 3 of BP at different load intervals: interval 1 (55–75% 1-repetition maximum: 1RM), interval 2 (75–85% 1RM) and interval 3 (85–100% 1RM). Kinematics variables were determined using the Xsens MVN Link System. Results showed that full ROM was higher in left than right shoulder at all intensities (<i>p</i> = 0.008–0.035). V<sub>MEAN</sub>, V<sub>MAX</sub>, A<sub>MEAN</sub>, and A<sub>MAX</sub> were different in both shoulders for interval 3 during phase 2 and were lower as load intensity increased in both shoulders (<i>p</i> = 0.001–0.029). During phase 3, only V<sub>MAX</sub> on interval 2 was different between shoulders. Moreover, V<sub>MEAN</sub>, V<sub>MAX</sub>, A<sub>MEAN</sub>, and A<sub>MAX</sub> were greater during interval 1 compared with the others in both shoulders (<i>p</i> = 0.001–0.029). Therefore, there exists a kinematics asymmetry between both shoulders during phases 2 and 3 of bench press, although the acceleration was similar during both phases at all load intensities. Moreover, kinematic parameters differ between loads of 55–75% RM compared to 75–100% RM loads.