Electromyographic analysis in upper limbs of Brazilian air force flight instructors submitted to maneuvers in a T-27 force simulator

Abstract

Aim: The specific professional activity of pilots is dependent of health status. Health hazards associated with acrobatic flight may have negative aspects, since pilots do not always receive precise preparation for certain situations. Together with a complex position and an increased gravitational load, the acrobatic movements place high demand on skeletal muscles and circulatory system. The aim of this study was to evaluate the mean and peak electromyographic amplitude of upper limbs in Brazilian Air Force flight instructors submitted to a reproduction of acrobatic maneuvers (Looping, Tonneau Barrel, Tonneau Slow, Returnemant) using the Force Simulator Prototype (SFA-EMB312/T27). This study is of fundamental importance to prevent shoulder injuries in Brazilian military pilots. The incidence of detachment and injury due to the high forces generated in the joystick is very high. Methods: Twelve male flight instructors participated in the study. Surface electromyography was used to analyse ten muscles of the upper limbs during four movements (the front, the back, external rotation and internal rotation) on a Force Simulator Prototype (SFA-EMB312/T27). The Root Mean Square (RMS) of the signal, expressed in microvolt's (mV; mean±SD), was calculated through the electromyographic amplitude of each selected muscle in all maneuvers. Results: There were higher mean electromyographic activation (EMGa) for the Anterior Deltoid muscle (162,280±60;mV) in the front movement; the Flexor Carpi Radialis muscle (123,349±36;mV) in the back movement; the Brachial Biceps muscle (314,587±73;mV) in the Internal Rotation movement; and the Posterior Deltoid muscle (545,028±125,5;mV) in the External Rotation movement. The mean EMGa indicated greater total muscle activation (132,592±157;mV) in the External Rotation movement. Results of peak EMGa showed that the highest values were presented for the Anterior Deltoid muscle (334,234±109;mV) in the front movement; the Flexor Carpi Radialis muscle (407,969±114;mV) in the back movement; the Brachial Biceps muscle (440,263±120;mV) in the Internal Rotation movement; and the Posterior Deltoid muscle (1277,229±333,5;mV) in the External Rotation movement. Conclusion: Our data demonstrated that some maneuvers within acrobatic flights require a higher demand for specific muscles of the upper limbs. Further research is required to define the influence of physical training as well as volume, intensity and optimum loads to improve pilot performance and safety, and to prevent injury during acrobatic flights.