You can actually do a flexoin test on your own. Do some research, learn all about it, then have a friend help you out. It "should" tell you pretty quick if there is a soft tissue issues in that leg. Then, if you know there is a problem, you will have information for the vet rather than a vague description.
A quick search on youtube found me these two... but I watched with the sound off, so I don't know what they were saying. I really like the second one - but again, I only watched, did not listen.