Someone recently asked:
I have had a history of hip flexor pulls when doing speed work. Since we know the psoas is the only hip flexor that works above 90 degrees can sprinting help this problem even if I get hurt when I go all out? I have read a lot of experts telling me that the psoas needs to be trained in order to activate it and the corrective exercises need to be done in the warm-up instead of my normal program. Any ideas?
Interesting. I have a sneaking suspicion you have been reading some what I call myth interpretation of the role of the psoas and how to fix the problem. When sprinting the psoas is not going above 90 degrees ever in elite sprints unless the athlete is high stepping after victory or something similar such as a drill or warm up. The other problem is that when the knee goes above 90 degrees the hamstrings can place the the pelvis in posterior tilt and cause ballistic spinal flexion if one is doing them vigorously. Since the spine is not loaded I don’t think a high knee drill will blow out someone’s back but are we really doing strengthening of the psoas or conditioning it? Another question is if the Pectineus, Adductor Longus, and Adductor Brevis have good muscle tone and have been strengthened specifically? Those muscles are secondary hip flexors and often are over recruited when the primary hip flexors are fatigued or when the psoas is tight and inhibited.
With the psoas being a lumbar stabilizer in walking and running we must understand that is can be locked and not functioning from being tight. The psoas needs a combination of flexibility work statically, not ballistically as the role of sprinting is more elastic vs concentric. Isometric exercises may help at low levels but they are not solutions. Good static and therapy is the answer, and core work that doesn’t treat athletes like babies will often engage the legs a bit indirectly. I have seen more weak hip flexors from the removal of conventional ab programs in order to save the spine, causing low back problem indirectly later from poor psoas health. The solutions are not available in a cook book approach so it’s best to see a real PT that is known for problem solving.