The aim of this study is to develop a biomechanical model and a method to analyze the kinematic and kinetic features of the handcycling activity. By applying this model, the contribution of important factors, like muscles, inertia and weight, on the biomechanics of the handbike is investigated. In order to validate the proposed model, the kinematics and kinetics of the arm have been collected during a handcycling activity in different configurations performed by several subjects. The force applied on the handle has been measured and compared with the one assessed by the model; in addition, the arm muscles activity has been noticed. Moreover, some new indices are defined to describe the performance of handbike athletes in a more precise way to improve their benefits.