Phonomyography
Phonomyography (PMG) (also known as acoustic myography, sound myography, vibromyography, and surface mechanomyogram) is a technique to measure the force of muscle contraction by recording the low frequency sounds created during muscular activity.
Although, until recently, less precise than the more traditional mechanomyography, it is considerably easier to set up. The signal is measured using condenser microphone elements, piezoelectric sensors, accelerometers, or a combination of sensors attached to the skin. Hydrophones have also been used to measure muscles immersed in water. Improvements in microphones and contact transducers (piezoelectric devices), as well as recording systems, has meant that they have become available in a size and of a quality that enables them to be applied to a normal daily setting outside the clinic and the laboratory setting. These new possibilities provide a clinical tool for the assessment of patients with musculoskeletal complaints during daily activities, or assessment of athletes in terms of efficiency in use of muscles.