For researchers in electromyography (EMG), and similar biosginals, signal processing is naturally an essential topic. There are a number of excellent tools available. To these one may add the freely available open source statistical software package R, which is in fact also a programming language. It is becoming one the standard tools for scientists to visualize and process data. A large number of additional packages are continually contributed by an active community. The purpose of this paper is to alert biomechanics researchers to the usefulness of this versatile tool. We discuss a set of basic signal processing methods and their realizations with R which are provided in the supplementary material. The data used in the examples are EMG and force plate data acquired during a quiet standing test.