Neck lateral flexion/extension

In 2000 (and on a few other occasions) I published and claimed copyright on this exercise description (bolding added now):

Neck lateral flexion/extension:

Using a partner and a towel perform slow controlled lateral flexion and extension of the neck (i.e. face forward tilt the head to the left and right.

I was conducting research and I came upon the following exercise in a publication copyright claimed by another 'author' at a subsequent date (bolding added):

Neck lateral flexion/extension:

Using a partner and a towel perform slow controlled lateral flexion and extension of the neck (i.e. face forward tilt the head to the left and right.

And I said to myself: “That looks familiar!” So I cross-referenced it and I said to myself: “Wow! No wonder that looked familiar!”

I noted that the use of this description was in the absence of credits or references to the origin or permission to use from the original author (myself), and that the 'author' claimed copyright....