Nothing specific can be said for a leg length discrepancy in a forum such as this because leg length discrepancy has many causes. As a boot fitter and ski instructor I am cautious whenever I encounter a difference. Trying the wrong fix can aggravate other medical conditions and make things worse in the long run.
I basically put leg length discrepancies into two categories. Anatomical meaning joint and bone issues and Functional meaning muscle/ tendon imbalances pulling things out of whack. It is not always easy to determine what the cause may be. The first thing I do is ask and often times the person is well aware of what the problem is.
If the leg length discrepancy is related to muscle imbalance the obvious thing to do is address that issue with physical therapy or some other type of structured approach. Muscular imbalances can be long term where the persons skiing does not really change over time or vary widely during a single day and may involve muscle cramping. Sleep and dehydration are big culprits in leg length changes within a single day.
When it comes to anatomical differences the approach needs to be cautious. The easiest fix is if the leg length discrepancy is under a half inch and exists in the tibia/fibula (lower leg) where a simple lift may cure the problem. If the discrepancy involves the knees, ankle, hip joint or spine you need a doctor involved in the fix. You can be in for some real hurt with innocent seeming fixes. If the problem exists in the femur and is not greater than a half inch you have some options depending on your skiing style but still a doctor should be involved. Greater than a half inch in the femurs and I doubt you will get a real satisfactory fix although you can improve the situation.
What you see on the snow depends on where the problem is and what the skier perceives and to a large extent on what the skier thinks is good skiing. In general what you will see is a difference in ski tip lead between right and left turn and in a simple traverse both directions across the slope. You will tend to see banking/ inclination to start a turn where the short leg will be on the inside and a shoulder rock or counter rotation with tail push or hip angulation to start the turn when the long leg will be on the inside. There is likely to be a tendency to hang onto the turn longer when the new inside leg for the next turn is going to be the longer leg.
The skier with a shorter leg is also less likely to be aware of the compensations and not know what they look like skiing.
Edited by Pierre - 1/6/16 at 9:19am