Yeah. It is hard to tell what is going on without an actual diagnosis. Also, it is worth understanding that our nervous systems are complex. Where you have pain, and where the problem actually is, they are not always the same.
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If the issue is your iliopsoas, stretching it may or may not be useful. But it would not hurt trying.
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However, the pain you are describing, and where you are describing it, could equally be caused by nerve impingement in the lumbar spin which sometimes can be exacerbated by bending over. For sure, this could cause referred pain right where you are describing.
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And, without the kind of testing Baal referred to (MRI) it would be hard to tell what the cause of the pain is.
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But, if you find something that helps that pain go away, keep doing it (perhaps, something like stretching the hip flexor muscle). BTW: the iliospoas is not the only set of hip flexor muscles. The quadriceps muscles are also primary hip flexor muscles. But they only cross the hip joint whereas, the most superior (highest on the spine) attachments of the psoas part of the iliopsoas crosses all the joints of the lumbar spin, the sacrum, and the hip joint.
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Exercises that cause those muscles to work (leg raises) before stretching them might also be a good idea so that you are strengthening them and then taking a short amount of time to lengthen them.
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Over the internet, it is hard to say what exercises or stretches would be useful for a person, particularly without seeing the person move and use their body. And it is worth knowing that, there is contradictory information on whether stretching muscles is useful. But I can say with certainty, when a lot of people I see try to stretch, they don't know what they are doing and cause more harm than good by how they try to stretch.
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So, be careful. Anything you try on your own that makes what you have going on feel worse, is not what will help it get better.