I think the other shihan that Homma refers to as having injured his knees and therefore relies almost entirely on hand movement is Tamura.
I doubt it. Although Tamura's style can appear magical to those who do not understand it, I don't see how anyone could claim that he is only using his hands. Also, I don't know that Tamura has any injuries, and compared to Homma he is certainly not a "contemporary" instructor.
I suspect he is most likely talking about Ikeda
, who has knee problems so bad that he no longer even sits for the opening and closing bows. Homma has also been critical of Ikeda before (again not by name, but on more than one occasion he has criticized people who sell designer aikido gear
, of which Ikeda is a very prominent example). Sounds like there is a bit of bad blood between them. Not too surprising given their proximity and that they are competing for students somewhat.