Tight hip flexors, especially a deep muscle called the psoas, can silently stress your spine. Here's why this muscle deserves ...

“The psoas is a massive hip flexor muscle that runs from our lumbar spine ... tight and weak simply because it isn’t getting any action or even the slightest movement.” ...

uq.edu.au Objective In this study, asymmetry relative to the preferred kicking leg was determined if it exists for the psoas and quadratus lumborum muscles among elite Australian Football League (AFL) ...