Serene Equine: Bodywork and Biomechanics puts out a bimonthly newsletter filled with education, tips, case studies, try this exercises, book reviews, fun, and more! Below is a screen shot of our June 2022 edition.

Here is the link to the rider asymmetry discussion from the previous issue that is mentioned in the above image:
Rider image analysis
And to the silly putty example of muscles:
muscles need warmup

And a screen shot from the June 2022 issue, the organization is different but this gives an idea of topics covered.