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

Loosen tight hips and open your hip flexors and psoas with this quick 5-minute yoga stretch. Perfect for a break during the ...

Results At all three time points, the CSA of the psoas muscle was significantly greater ipsilateral to the kicking leg, while the CSA of the quadratus lumborum muscle was significantly greater on the ...