Scroll down to the bottom of the page. You will find the comment box there.
Disclaimer: PD Movement Lab is a strictly educational website. It does not provide medical advice, diagnosis, or treatment, and the content on this site is in no way intended to be a substitute for medical advice, diagnosis, or treatment. Always seek the counsel of your physician, or another qualified health provider with any medical questions you have. Never disregard professional medical advice or delay in seeking it because of something you have read on this site.