Optimizing Muscle Activation in Cadets Using Electromyography Biofeedback During Anti-G Training

Effective execution of the anti-G straining maneuver (AGSM) is essential for pilots to maintain consciousness under high gravitational forces (+Gz). This study evaluated whether electromyographic (EMG) biofeedback enhances muscle activation patterns during AGSM training in novice cadets.

There were 58 Brazilian Air Force cadets (age: 25 ± 1 yr) who performed two AGSM sessions involving sustained submaximal isometric contractions of the gastrocnemius, vastus medialis, and rectus abdominis muscles, synchronized with rhythmic breathing every 3 s. Subjects completed trials under counterbalanced visual EMG feedback conditions (real-time visualization vs. no visualization) and were randomly assigned to verbal feedback conditions (instructor guidance vs. no guidance). EMG signals were recorded at 1500 Hz and normalized to each subject's peak amplitude during the AGSM trials.

Muscle-specific responses to feedback were observed. Verbal feedback enhanced gastrocnemius activation but reduced vastus medialis activation. Combined visual and verbal feedback produced the highest activation in the rectus abdominis. Visual feedback alone had minimal effect across all muscles. Despite submaximal instructions, brief peak activations were sufficient for normalization.

EMG biofeedback facilitated motor learning of AGSM by selectively improving activation in targeted muscles. However, effects varied by muscle group, suggesting the need for tailored instructional strategies. Although task-based normalization offers ecological validity, it may limit comparisons with MVC-based protocols. Incorporating EMG biofeedback may enhance AGSM training, particularly in novice populations or settings without centrifuge access. Massaferri R, Calvo APC, Coutinho ABB, Guimarães TT, Farinatti P. Optimizing muscle activation in cadets using electromyography biofeedback during anti-G training. Aerosp Med Hum Perform. 2025; 96(11):985-992.