One of the training mistakes I made - in a quest for mighty hip flexors, was to put my foot through the loop of a kettlebell. I would do 300 reps on each leg, each day, in a standing position. I usually did 15 reps per set. Another method was to flip a lorry tire, over and over again, using my foot under the tire.
The problem is thta both of those inovative training methods actually messed up my muscle lengths ofr sprinting and slightly slowed down my speed. You see; the support legs’ hams and glutes were tightening, and the calf was over-active. Not only that, but there was eventually; a cumulative fatigue, actually preventing me from getting enough knee lift.
More food for thought:
We are told that the psoas is only active when the thigh is at least at a right angle to torso, and higher.
We are told that the psoas muscle size is more important than the size of other hip flexors such as rectus femoris. (the Japanese study).
Most ‘hip flexion’ exercises tend to do more for rectus femoris and sartorius than the psoas - therefor; not helping point 1 and point 2
If we were to do gym exercise that work only in the physio and anatomists suggestion that psoas is only actyive in upper range - then we wouldn’t be getting full range of motion - would not be getting a dynamic exercise - and could actually get shortened and tightened psoas. From here - the psoas tends to have a mind of its own. Some profess that shortened and tightened psoas is in-active and non functional.
So what we have is a bucket load of contradictions and a puzzle.
The question is:
How do you;
Nightmare. Lets have more discussion because it is important. I stopped doing incline sit uops a long time ago, as they seem to do more for the rectus femoris than the actual psoas major.
After all, in the incline bench, your feet are braced under pad, thus requiring rectus femoris contraction to anchor the legs.
The psoas, rectus and iliacus work together to hip flex if the rectus is recruited then so be it. Synergy not isolation is needed. The psoas will be recruited to stabilise the spine and assist in flexing the hip and thigh.