No. You're confused about what constitutes as "communication". Communication does not mean conversation. The knee isn't conversing with you, but information is absolutely being communicated.

I would recommend familiarizing yourself with information theory and systems theory.

From the opening line on the Wikipedia article for Communication:

> Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether unintentional or failed transmissions are included and whether communication not only transmits meaning but also creates it.

If you argue from a position ignorant of information theory, it might seem that a knee jerk is not communication. But read through Shannon's A Mathematical Theory of Communication and you will understand differently.

https://en.wikipedia.org/wiki/Communication

https://en.wikipedia.org/wiki/Information_theory

https://en.wikipedia.org/wiki/Systems_theory