Whats wrong with the ‘core trunk’ concept?

“Brain knows movement… Not muscles..” (Beevor 1903)

This insight from over 100 years ago highlights the problem of squeezing muscles and bracing cores. We don’t learn this way and it only engenders fear and is not functional. Low back pain does not improve with this approach. http://www.ncbi.nlm.nih.gov/pubmed/22135712