Adaptation of the Lower Extremity Neuromuscular Activation While Performing the Ross Submaximal Cardiovascular Test in Healthy Adults

Background: Submaximal exercise tests using treadmills are reliable predictors of cardiovascular and musculoskeletal performances in adults. Understanding neuromuscular lower extremity muscle activation during treadmill walking can help clinicians tailor rehabilitation and training programs for their condition. Subjects: Ten healthy participants (22.6 ± 1.08 years of age) were recruited for this study. Method: Participants were instructed to walk on a treadmill at a speed of 3.4 mph and 0% elevation for 3 min. The elevation increased every 3 min by 3% and 4% in women and men, respectively. Data on the muscle activation of the tibialis anterior (TA), gastrocnemius (GA), rectus femoris (QUADS), and semimembranosus (HS) were collected using surface electromyography. Results: There were slight differences in the muscle activation between the muscle groups at various intervals. The results revealed that the tibialis anterior and semimembranosus took longer to activate and showed trends of more extended activation periods with an increase in inclination. Conclusion: Analysis of electromyography (EMG) activity in healthy young adults during submaximal exercise testing on a treadmill revealed a delay in muscle activation and increased active time in the tibialis anterior and semimembranosus musculatures.