I have posted about a few different physical aids for learning the forearm pass. While there is some intuitive logic in all of them, the obvious question that one must ask is ‘does it work’. A friend recently answered this question with reference to Differential Learning Theory. I will post his answer verbatim to avoid misunderstanding.
You know that coaches, believing in … differential learning won’t agree with using this kind of things. Your neural feedback system in your brains don’t get information from their proprioceptors for adequate adaption in the brains. Better is it to practice with very small balls; in a more natural way you arms will form a better platform, because otherwise there won’t be a recognition off success. It’s all already in your “brainsystem” and it comes/adapt automatically. With board there is no neural traffic between the KR (knowledge of result) and the Declarative memory system ; so therefore it is difficult to get a transfer to the conceptual memory system. The outcome could be that the passing looks better now, but at the end will be worse.
Unfortunately, I can’t say that I am very familiar with Differentiated Learning Theory, but I have found this summary. It is very interesting and would seem on first reading to support the training principle of specificity.