Psoas tendonitis is typically from over working or an overactive hip flexor (which the psoas muscles are part of). To avoid this, it is important to limit the amount of hip flexor strengthening early on in the rehabilitation process. I don’t do any hip flexor strengthening with my patients untill 6-8 weeks post op.
If I encounter a patient with hip flexor pain. The treatment should be rest, ice, anything else to decrease the inflammation. Then when the pain becomes more bearable we start core strengthening and psoas relaxtion/ tone reducing exercises and core strengthening.
Most people try to stretch the hip flexor when it hurts and that tends to make it worse and it is why so many patients fail at conservative physical therapy approaches.
This is a good case study on what I have discussed above:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2642547/
Peter Schultz DPT, OCS www.DynamicSportsPT.com 133 E 55th Street New York, NY 10022 212-317-8303