This article describes the design and implementation of an electrogoniometer to measure joint angles during the execution of weight lifting exercises. The electrogoniometer consists of four microelectromechanical accelerometers connected to a microcontroller. The microcontroller is connected via USB to a computer. Preliminary tests show that the system offers high precision and accuracy at angle measurement. Error in the measured values is less than 0.3% when comparing to a commercial digital goniometer, and it is low cost.
