Movement planning and movement execution: What is in between?

Although the model proposed by Thelen and co-authors provides a detailed ex planation for the processes underlying reaching, many aspects of it are hig hly speculative. One of the reasons for this is our lack of knowledge about transformation of a hand movement plan into joint movements. The leading j oint hypothesis (LJH) allows us to partially fill in this gap. The LJH offe rs a possible explanation for the formation of movement and how it may be r epresented in memory. Our explanation converges with the dynamic model desc ribed in the target article.