Instrument assisted soft tissue mobilization (IASTM) is a form of massage using rigid manufactured or cast devices. The delivered force, which is a critical parameter in massage during IASTM, has not been measured or standardized for most clinical practices. In addition to the force, the angle of treatment and frequency play an important role during IASTM. As a result, there is a strong need to characterize the delivered force to a patient, angle of treatment, and stroke frequency.
This paper proposes a novel mechatronic design for a specific instrument from Graston Technique® (Model GT-3), which is a frequently used tool to clinically deliver localize pressure to the soft tissue. The design uses a 3D load cell, which can measure all three force components force simultaneously. The overall design is implemented with an IMUduino microcontroller chip which can also measure tool orientation angles and provide computed stroke frequency.
The prototype of the mechatronic IASTM tool was validated for force measurements using an electronic plate scale that provided the baseline force values to compare with the applied force magnitudes measured by the device. The load cell measurements and the scale readings were found to be in agreement within the expected degree of accuracy. The stroke frequency was computed using the force data and determining the peaks during force application. The orientation angles were obtained from the built-in sensors in the microchip.