Upper Cross/ Lower Cross Syndromes are outdated theories that should systematically be ignored. Have a look at the ever-expanding information showing why.
What poor posture is not: Upper-Crossed Syndrome (and its ilk):
JANDA’S LOWER CROSSED SYNDROME HAS NOT BEEN VALIDATED:
http://www.greglehman.ca/blog/2016/01/11/jandas-lower-crossed-syndrome-has-not-been-validated
Posture, Blamed for Everythingโฆ
A Facebook post on Upper/Lower Cross Syndrome by Robert Palka
Relationship between Hip Extension Range of Motion and Postural Alignment: https://www.jospt.org/doi/pdfplus/10.2519/jospt.1990.12.6.243?fbclid=IwAR1syxEbGpMCvymNgITp1P2TFQni9VQC378VAvzlTDe4zW5LQlJItYc_-JQ
Does Excessive Sitting Shorten the Hip Flexors?: https://toddhargrove.wordpress.com/2011/05/29/does-excessive-sitting-shorten-the-hip-flexors/?fbclid=IwAR0p2PdqprltV-ANNLkOMgx9uetf_ITD84EoYJpBVXFvmi5Ne0zq-YDaqf0