Hi
If your physio is right about the muscle imbalances then usually the functional leg length discrepancy along with ascoliosis means you have:
- over development or shortening of the muscles that pull your leg in to the other one on one side (hip abductors)
- lengthening or weakness of the muscles that pull the leg out to the side (hip abductors)
- The opposite pattern on the other leg
- likely shortening of the muscles on one side of the spine and lengthening/weakness on the other side (could be a number of muscles but quadratus lumborum is often the culprit)
It could be any or any or all of these things. Have a look at these muscles in an anatomy text or website. If this is the case and there is not true leg length discrepancy (ie thigh bone and shin bones are all equal length) and the bony pelvis is even then the rational treatment is strengthening in the shortened position of the lengthened/weakened muscles and lengthening exercises of the shortened muscles. You usually also need some help with changing your patterns of movement which probably underlie the development of this problem.
So... your physio should have given you such a programme. It takes time (several weeks to months), you have to adhere to the programme, and is very specific but can be effective. that is all considering if this is the problem. The stretching component should be gentle and sustained over a long period of time. If you are getting sore from the exercises then something is wrong. A build may help in the overall management but in itself is not such an effective strategy as it isn't really dealing with the underlying problem.
Looking at your age this is a great time to get on with this - it may save you suffering later in life as well as improving your enjoyment of walking, running etc.