[Properly pronounced] If you fill in the blank: “My psoas are as sore as ____!” with an expletive, or if you don’t know what the psoas is, then you might want to read on. https://www.sportsinjurybulletin.com/psoas-major-part-i-hip-flexor-or-lumbar-stabilizer/ Did you know the psoas are the only muscles that connect the upper body to the lower body? You probably…