It is fifteen years since volume on this question was Volume 3 of the IFF Feldenkrais Research Journal: 2006/2007, in that time a lot of research has been published, and a growth in sophistication of understanding of the Feldenkrais Method and of possible research methods.
The Feldenkrais Research Journal focuses on research into the Feldenkrais Method® and related fields of practice, thought, research, action, and awareness. This peer reviewed Journal seeks to engage in a dialogue about research within the Feldenkrais professional field and beyond.