The purpose of the study was to investigate the biomechanical effects of different types of braces that are used in the treatment of patients with epicondylitis radialis. Vibration and acceleration of the forearm and the elbow were measured with sensors taped to defined anatomic points on the skin surface. The impact-induced vibration of the racket-arm system was analyzed while the subjects were playing tennis. Different designed brace systems were investigated with respect to acceleration amplitudes and acceleration integrals. Clasp-based brace systems showed a slight reduction of acceleration amplitudes (-6%) and acceleration integrals (-8%). Braces with pads at the lateral epicondyle reduced acceleration amplitudes by 20% and acceleration integrals by 22%. Braces with pads placed at the forearm showed the highest reduction of acceleration amplitudes (-46%) and acceleration integrals (-42%). Overload of the wrist extensors, which is considered to be a major pathogenic factor in lateral epicondylitis, can be reduced by braces. There is a significant difference in the effects among different biomechanical principles of braces.