The importance of a movement assessment:

The body is a chain; each link effecting the others. When one of those links is dysfunctional, the entire kinetic chain becomes weak. Muscle balance is essential to transfer force, accelerate, decelerate, and stabilize. Muscular imbalances can occur from trauma, repetitive movement, stress, sedentary lifestyle, disease…you get the idea. The result will be a functional movement impairment and eventually injury.
Take control of your own well being. First (of course) I recommend finding a qualified trainer experienced in doing movement assessments (call me if you need a referral). If this can’t be done, do a spot check on your self.
The easiest way is to do an over head squat assessment in a mirror.

Stand with your feet hip width apart, feet facing forward. Raise your arms above your head and straighten them at about a 45-60 degree angle to the sides. Slowly complete a number of squats without changing your position.

What you are looking for is:
Do your feet turn in or out, or do they stay forward?
Do your heels come up off the ground?
Do you loose your balance?
Do your knees move in or out, or do they stay forward.
Does you low back round or arch?
Do you have to lean forward to stay balanced?
Do your arms fall forward?

If you answered yes to any of these questions, you have an imbalance that will sooner or later cause an injury to muscle tissue or a joint.