Someone in the comments asked about how to re-establish good movement patterns. I don't claim to have all the answers on this, but I would point out a few resources:
Stability, Sport, and Performance Movement by Joanne Elphinston
Athletic Body in Balance by Gray Cook
John also pointed out Scott Sonnon's Circular Strength Training, though I don't have any experience with that.
A big part of Gray Cook's work is his Functional Movement Screen. This is a simple series of tests that show movement deficiencies. Wouldn't it be great if gyms offered a Functional Movement Screen (or something similar to it) for new members? This could contain very valuable information if a person found out they had major asymmetries or mobility issues. They could address these problems before piling on the weights or the repetitive aerobics.