This paper analyses diversity and intersectionality aspects in the R&D of wearable assistive and rehabilitation technologies (WEARTechs). We advocate for inclusive, innovative research that we hope will help bridge the gap between laboratories and the real world and reduce disparities in healthcare and technology development. We performed a systematic literature review of the intersections between assistive technologies and diversity and conducted a thematic analysis of the diversity factors identified in the literature. In addition, we carried out a supplementary literature search on WEARTechs to discover which, if any, diversity aspects are currently being reported on. Our findings indicate that diversity has not been addressed in the field of WEARTechs. There is not sufficient knowledge to determine, which diversity-related aspects researchers must consider when evaluating the performance of any specific WEARTech device. Nor about how these can be properly addressed in the R&D process. We, therefore, provide actionable recommendations on how to integrate diversity-relevant aspects at different R&D stages. We hope that our review will help scientists rethink and reformulate approaches to the R&D of WEARTechs and build the way towards more inclusive solutions. It is our belief that this will spark innovation and enhance discovery potential in the field.