Importance of the Psoas muscle

In short I have a question: Is it even possible that I could function (walk etc) without a properly functioning psoas?

The long story: For the past two years I have been struggling to find the route cause of muscular imbalances on the right side of my body. I have tight hip flexors, hamstrings and lower back muscles and weak glutes and psoas muscles. I find it hard to breathe because of the tight back muscles.
It's been going on for so long because progress I make whilst static (hip flexor stretches, hamstring stretches) tends to be undone once I start walking.

The reason I am worried about my psoas is this: When I raise my left leg as if to walk, I feel (from the outside) a contraction in my lower abdominals. When I raise my right leg I do not feel this and afterward I feel the muscles around my waist/pelvis (hip flexors?) and upper thigh and gracilis muscle are very tight. So there is a definite difference in the way the two sides of my body function when being raised. The most obvious thing I can think of to explain the above is it's almost as if my psoas isn't working and so my thigh, illiacus and gracilis are overcompensating for it.

I had a car accident many years ago in which my pelvic/ waist area was squashed between two cars as one reversed into me, pinning me against another. I had no scans done and was shortly released from hospital. I am wondering whether it is possible that my psoas could have become damaged/ruptured then and my body forced to compensate.
Although on the other hand I think I'm being over the top and that perhaps I would surely know about it if it were that serious i.e. intense pain in certain situations, inability to walk properly etc.
Should I try and get this investigated further through scans etc or is it out of the question?
Thanks in advance for any enlightening opinions.

Hi Subscript

To answer to your initial question us is that motor control of muscles by the nervous system is a highly resourceful system can readily adapt to physical constraints by such things a muscle damage. How efficient those adaptions are may involve how much damage there really is and the type of adaption selected. For example Psoas is just one part of the hip flexor group so even with major damage it is possible for other muscles to compensate.

You sound like you know quite a bit about your muscles and are quite aware of what specific muscles you are using. I am not sure if are being a bit overly focused on your movement or you just have a heightened awareness of what you are doing, muscle wise. I does sound like you have an assymetry in your gait. Whether or not that is due to your old car accident may just be conjecture at this stage. Yes it is possible you suffered structural damage at the time. Another possibility is that if you were in pain following the injury you may have developed an altered motor pattern for getting around the problem which has just become habit ie not so much a structural but more of a functional change. This in time results in relative hypertrophy and atrophy of various muscles - sort of a muscle imbalance problem. If you are getting a tightening response this may suggest such a functional difference

Yes you could seek an MRI to but even the high resolution of the scan would only pick up gross structural changes. This can end up being a high cost test that may not show up what you are looking for but it would certainly rule out major structural changes. Real time ultrasound that a phyiso who is trained to use could be used to see the contraction of deep muscles such as psoas and other muscles and the advantage of this technique is that you can see the muscles work when performing a particular task (eg the poas belly circumference can be seen to suddenly increase when you attempt to bend the hip while being scanned.

In terms of doing something about it. a more educational approach may be to try something like some lessons with a Feldenkrais Practitioner. A skilled practitioner (someone who is dual-trained as a physio and a Feldenkrais practitioner) may help you become more aware of what you are doing and give you some alternative options in your movement. There are also a number of physiotherapy options such as clinical pilates, movement impairment syndromes approach which could target the problem.

At the end of the day you could be stressing about something that isn't such a problem but as it is worrying you why not get it checked out? No harm in finding out and if a solution can be found it may have some long term benefits for you.