These are the Footkeepers and you can see the adjustment lever behind the footrest.
http://www.clcboats.com/images/products/keeperfootbraces.jpg
There are the Yakimas with the lever also behind the footrest.
http://www.clcboats.com/images/products/footbraces.jpg
These are both for non-rudder use.
Glen in Baie-St-Paul.