A system (100) and method for the non-invasive measurement of tone, state of tension, biomechanical or viscoelastic properties of soft biological tissues (125) comprises a testing-end (1), an actuator (3) arranged to apply a force to the testing-end (1), and a sensor (2, 21) to sense movement of the testing-end (1). The system comprises a signal generating circuit (6, 10) to supply a control signal to the actuator (3) so the biological tissues are subjected by the testing-end (1) to a load, including means (5) to adjust the signal provided by the signal generating circuit (6, 10) in accordance with the component of weight acting through the testing-end (1) onto the biological tissue so that the load to which the biological tissue is subjected is constant. It also comprises an impulse signal generating circuit (7, 10) to supply an impulse signal to the actuator (3) so the biological tissue is subjected by the testing-end (1) to a mechanical deformation. In use the soft biological tissue is subjected first to the constant load, and then to the impulse signal； and the consequent movement of the biological tissue (125) is then registered.
