The development of algorithms for motion discrimination in home rehabilitation sessions poses numerous challenges. Recent studies have used the concept of synergies to discriminate a set of movements. However, the discrimination depends on the correlation of the reconstructed movement with the online data, and the training data requires well-defined movements. In this paper, we introduced the concept of a synergy probe, which makes a direct comparison between synergies and online data. The system represents synergies and movements in the same space and monitors their behavior. The results indicated that conventional methods are influenced by the segmentation of training data, and even though the reconstructed movement is similar to the ground-truth, it does not provide sufficient information to evaluate the data in real time. The synergy probes were used to discriminate and evaluate the performance of natural whole-body exercises without segmentation or previous determination of movements. An analysis of the results also demonstrated the possibility to identify the strategies used by the subjects for movement. Such information aids in gaining a better insight and can prove beneficial in home rehabilitation.