You're aware that the hyper is used in back rehab?
Even better is something called the reverse hyperextension. The upper body is locked while the legs are lifted.
This I would agree with...the reverse hypers. In a general low back case the facet joint will often be irritated and you have the possibility of a posterior bulge in a disc. By doing a standard hyper, this will only add to the irritation as compression in a superior to inferior direction will sometimes exacerbate the condition. This is the reason for reverse hypers as the load comes from the legs....not the torso.
As far as the psoas is concerned....I disagree in that the hip flexors are generally stronger and over facilitated in people now a days. Most of the people with any sort of low back issues exhibit similar patters to a lower cross syndrome where in the hamstrings, erector spinae , piriformis, quadratus lumborum, adductors, tensor fascia latae, rectus femoris and the iliopsoas are over facilitated. The weak/inhibited ones are the gluteals, vastus medialis, vastus lateralis, transversus and the rectus abdominis. Along with that the tight hamstrings will add extra "pull" on the pelvis due to the fact that the majority of fibers insert into the sacro-tuberus ligament.
Now Wooo.....Coach seems to know his shit.....and is trying to give you some sound advice. Yet, you dotn seem to want to listen. You hurt yourself, and you need to rehab your back. YOU are the one who is retarded and will not listen. You like 80% of the athletes that come into my office for treatment. YOu whine and cry about your injury and when given a solution you think people are bullshittting you and holding back from giving you the "holy grail" of exercises that will magically fix you . This is why I dont exactly like treating athletes as patients.
Woo.....go and read up on things by Paul Chek....tell him he is full of shit!