Measuring Leg Length

How do you assess a patient to see if they have a leg length discrepancy? If they do, what could it mean exactly? (Is it an instability in the hip, a muscle locked short or long, etc) If it is not a true LLD, would you attempt to fix it? If so, what would you do? Lastly, do you think trainers should be looking at this before we begin a session and trying to fix it? There are probably a couple ways to measure leg length, but the valid by my standards (I don't know what the literature says) is this.Tape measure from ASIS to medial malleolus.For better at least intra-rater reliability, I would suggest thumbing up from underneath the bony landmarks, and measure from where the button starts to jut out. This way you can have a good shot at measuring the same way every single time.You can measure standing bilaterally, standing on 1 leg, and then laying down in the both positions also.If there is a consistency, then there is really a leg length difference. If there is a difference standing vs. unloaded, it's a muscular tension somewhere.If it is a very real structural difference, the shoe can be built up.  Or you can have an osteotomy somewhere if you want.  That might not be preferrable though.If it's a muscular dysfunction, it can/should be fixed.I would say you probably don't need to be looking at it, especially at first, because if it's real, I've got to think the person already knows. If it's functional, it will come out in the wash with the FMS asymmetry.I typically discard anyone that tells me they have a leg length discrepancy especially from another clincian. It's part arrogance on my part, and part I know the reality that it will come out as we go through the movement screening and assessment. Leg length itself is a Test. It doesn't tell me enough.I think the key here is this.  Always look at dynamic patterns first.  If the person moves well, that is all we care about in the first place.  If there are major problems or asymmetries that show up, they should be addressed.  Tag out if you have to.But static postural tests and exams should only come after movement has been exposed to be in error.