Analysis of Survival Probability and Its Association with Time to Task Failure in Induced Fatiguing Dynamic Contractions of Biceps Brachii Muscle using Surface Electromyography

In this study, an attempt has been made to model the survival probability of muscle to predict time to task failure (TTF) during dynamic fatiguing contractions. For this purpose, seventy-three subjects are recruited to perform dynamic elbow flexion task with 3 kg and 6 kg-load dumbbells. Surface electromyography (sEMG) signals are recorded from the belly of biceps brachii muscle and time to task failure is noted. Survival analysis is performed using two probabilistic models, namely Weibull and Log-logistics, and Akaike Information Criteria (AIC) is utilized for model comparison. The results show that both types of distributions can be used to model the survival probability of muscle during fatiguing task. The AIC values are comparable between models, but it is found to be higher in case of loading with 6 kg. For twice the loading levels, the ratio of the scale parameters of distribution models are found to be 2.80 and 2.43 respectively, which is comparable with the ratio of 2.60 for the median RMS value in the first curl. The results demonstrate that the approach to model survival probability of muscle can aid in prediction of TTF during fatiguing tasks. This study could be clinically relevant in domains of sports medicine and applied ergonomics.