The Anterior Chain

[Charlie_Francis]

@rj24

Goose, your problem didn’t stem from training the Psoas, but from doing it wrong in a number of ways. You were fed misinformation and/or interpreted a few things wrong as well. Not only were you training over the wrong ROM, but you added in the exercise without any idea of what it would do to you. As such, the volume burnt you out and the trained ROM increased reduced the flexibility of your psoas.

As for activation, Martn is right. The thigh does not need to be at a right angle to activate the psoas. In fact, training in this range will promote posas tightness. As I stated in the article, the best ROM over which to train the psoas is with the spine held neutral and the thigh in line with the body. The exercises I suggested and demonstrated do this.

Regarding activation, you can’t, nor do you want to isolate the psoas when training. It will always work together with the other hip flexors. And you misinterpreted that Japanese study. Psoas CSA compared to quadriceps femoris CSA. The rectus femoris is one of four quadricep muscles, and hypertrophy in it alone is very beneficial to sprinters for a number of reasons.

The rectus femoris activation you get from doing decline sit ups is just fine. Not only does the RF aid in hip flexion, but it also acts isometrically to transfer forces generated during through hip extension into knee extension. It’s a very useful muscle.

EDIT: Also, on the topic of anterior pelvic tilt, most sprinter display it while walking around, but once sprinting their pelvis is held neutral or even posteriorly rotated. There are very few situations in which I would actively try to have someone tighten their psoas.

Can you illustrate some of the exercises so there is no misunderstanding?