: Information regarding two versions of an instrument called a muscle dynamometer, which enables detailed information about muscle activity in the deep stabilisation spinal system (DSSS), presented in this article. The MD01 (muscle dynamometer ver. 01) is a simple electromechanical instrument that allows measurement of muscle activity in two areas of the lumbar spine region. Measurements on patients have confirmed the usefulness of quantifying the initial state of a patient before rehabilitation as well as monitoring rehabilitation treatment; the MD01 is a suitable device for obtaining these measurements. However, a new and improved version of the MD01, the MD02, has been developed. The MD02 allows measurements in four different body regions and now has a PC interface, which allows achieving of patient information and data export for use with statistical software.