Peripheral somatosensory stimulation and postural recovery after stroke - a systematic review

Purpose It is hypothesized that peripheral somatosensory stimulation (PSS) can promote postural recovery after stroke by increasing afferent input and postural contribution of the paretic leg. Therefore, this systematic review aims to investigate which PSS approaches are documented and investigated on effectiveness. Methods Five databases (PubMed, Web of Science, PEDro, Cochrane Library Trials, RehabData) have been searched on clinical studies in stroke rehabilitation, investigating PSS, which is defined as a non-motor and focal stimulation to the paretic leg aiming an increase in somatosensory input. Results Twenty studies present different PSS approaches (mainly electrical and vibration stimulation) and following results: (I) There is an immediate effect after a single session of PSS on postural stability. In contrast, (II) repetitive sessions of isolated PSS led to highly inconsistent results. Finally, (III) PSS as an adjuvant to exercises did promote long-term postural recovery. Conclusion PSS is found to be effective immediately and on a long-term as an adjuvant therapy only in improving postural stability in a chronic stroke population. However, if PSS enhances paretic leg postural contribution remains unclear. Future research is warranted considering promising results and high prevalence of postural instability impacting daily life of stroke survivors.