Muscle myography for human-machine interfaces: a review of sensing modalities and control interfaces.

Muscle myography encompasses a family of techniques for sensing muscle activity through its electrical, mechanical, and optical manifestations, offering non-invasive and embodied pathways for human-machine interaction. Unlike traditional input devices that are hand-centric and device-bound, myography-based interfaces enable hands-free, inclusive control for prosthetics, exoskeletons, teleoperation, and immersive computing, while also opening opportunities in rehabilitation and health monitoring. This review surveys the state of muscle myography with an emphasis on its implications for human-machine interfaces (HMIs). We examine established and emerging modalities-including electromyography (EMG), mechanomyography (MMG), forcemyography (FMG), electrical impedance myography (EIM), optomyography (OMG), and the recently introduced lightmyography (LMG)-highlighting their respective strengths, weaknesses, and the trade-offs between signal quality, robustness, and wearability. We also identify recurring challenges such as limb position effects, motion artifacts, sensor reliability, and clinical acceptability, and discuss strategies such as hybrid sensing, sensor fusion, and machine learning aimed at mitigating these issues. For the HMI community, the significance of muscle myography lies not only in technical performance but also in its potential to redefine interaction design, shifting toward interfaces that operate less as external devices and more as natural extensions of the human body.