Purpose The review aimed to provide a wider overview on the new application fields of MMG signal. A particular emphasis on measurements reliability and sensitivity was also given. Methods Five electronic databases were searched for eligible studies published between 2000 and 2014. Two authors assessed selected articles. Several domains (sensor types, participants' characteristics, experimental protocols, investigated muscle/s, measured parameters, and main results) were extracted for analysis. From a total of 1326 citations, 170 were selected for evaluation and 111 studies were identified. Results From the analysis of the literature it resulted that MMG signal (a) has a high level of reliability, especially for the parameters calculated during isometric contractions; (b) can be used to examine muscle mechanical activation and motor unit recruitment strategies under several types of exercise paradigms; (c) is influenced by the mechanical characteristics of cross-bridges and series elastic components, and may provide deeper insights into their behaviour under several physiological models; (d) could be a useful biomarker for triggering orthosis or multifunction access devices, and for the evaluation of patients presenting alterations in muscle function. Conclusions The MMG approach has been proficiently applied in several fields ascribable to both exercise physiology and clinical settings. This approach can provide deeper insights into muscle mechanical behaviour under several physiological models and for the evaluation of patients with altered muscle function.