Simultaneous measurement of forearm muscle activity, vibrational transfer and grip strength during the tennis forehand stroke using a novel wearable device - a pilot study

Elbow tendinopathy injuries are very common in tennis players. One of the commonly accepted theories describing the development of elbow tendinopathy is based on stiffness of the forearm skeletal muscle units, their repetitive overuse and vibrational transfer from impact in tennis. The objective of this study was to design, develop and test a novel microcontroller based wearable device which could simultaneously measure a player's grip strength, forearm electromyographic activity and vibrational transfer under realistic playing conditions. The device was tested on four tennis players of various playing levels (a previously WTA player, a qualified tennis coach and 2 recreational players) who were required to hit forehands cross-court with different spin levels (flat and topspin) into the back diagonal square following a specific height guideline. The results indicated that the device could record unique player technical profiles of vibrational transfer, racket orientation angle, grip strength and forearm muscle activity during the stroke. This study demonstrates the potential benefits of a wearable device to measure kinematic parameters associated with elbow injury development in tennis players, as well as provide coaching recommendations for potentially reducing the risk of developing elbow tendinopathy.