Looking for the subtle clues will help you. You should have hypotheses and work to prove or disprove them. 

“Remember, this client is displaying these weight bearing differences side to side for a reason, this is their adaptive strategy. It is your job to prove that this is the cause of their pain, their adaptive strategy to get out of pain, or this is now a failed adaptive strategy causing pain, yet still not the root of the problem.”

We used to call this a “windswept” presentation. It is not that it is incorrect, but it is so vague.  

Look at these fippy floppers. Look closely at the dark areas, where foot oils and whatnot have played their changes in the leather upper of the flops. The right f.flop displays more lateral heel loading, rear foot inversion if you will. You can even see that there is less big toe pressure on this right side and even some increased lateral forefoot loading. This client appears to be more supinated clearly. You can even see there is more lightness to the arch leather on the right, again, more supination is suggested.

The left f.flop suggests the opposite. More medial heel pressures and more over the medial forefoot and arch. 

Now this clients f.flops tell a story.  So, this client is being windswept to the right we used to say, appearing to pronate more on the left and supinating more on the right.  Why are they doing this? Is the left leg functionally longer and by pronating they reduce the functional length of the leg (yet, increase internal spin of the limb and the host of naughty things that come with that). Is the right leg shorter, and by supinating they are raising the ankle mortise and arch which helps reduce the length differential ?  MAybe a bit of both, finding common ground for a more symmetrical pelvis ?  Who knows. This is where you need your physical exam, but, now you have some hypotheses to prove or disprove. 

“Remember, this client is displaying these weight bearing differences side to side for a reason, this is their adaptive strategy. It is your job to prove that this is the cause of their pain, their adaptive strategy to get out of pain, or this is now a failed adaptive strategy causing pain, yet still not the root of the problem.”

Is there some right hip pain from the right frontal pelvis drift creating some aberrant loading on the greater trochanter from ITB tension ? Perhaps a painful right hallux big toe, and they are unloading it to avoid pain? Maybe some knee pain or low back pain ? Who knows? Take your history and start putting the pieces together, it is your job. Just don’t screen them and throw corrective exercises at them, you owe it to them to examine them, take their history, watch them walk, teach them about what you see, and then sit down, spread the puzzle pieces out, look for the straight edges and corner pieces, and begin to build their puzzle. 

Clues, they are everywhere, if you look for them.

Dr. Shawn Allen, one of the gait guys