A common cause of injuries associated with squatting is failure to maintain proper tension as you descend into and rise out of the hole. I see people at my current big box all the time squatting half ass and if the 1person out of 100 does get the desired depth, they are extremely loose. This is probably because they were told to go as low as humanly possible but forgot to burn in their brain the importance of tension throughout.
Try this: With no weight, relax into as deep a bodyweight squat as you are able; use a pvc like a barbell back squat. While in the bottom position, shift gravity to your heels, tighten up your upper back and abs, rotate the legs out at the hip by shoving the knees outward and engage the glutes and hamstrings. If you do this correctly, you should involuntarily rise out of your deepest position by an inch or two. This is the depth you should strive for with your squats, and no deeper to help avoid being to loose and "Butt Wink"
Notice how tension has spread the load, shifting stress away from the lumbar, knees, and ankles to the hips, hamstrings, and the entire posterior chain. If you don't get the desired depth you well never get the benefits of hamstrings at all either.
If you're having trouble with this on you own, be sure to grab someone that can either help you or set up a camera and record you ROM to review yourself.
04/27 Tuesday (MY Birthday) WOD
Strength
Bench Press 5x5x5
Weighted Dips 8x8x8
WOD
7 Rounds
7 Squat Cleans (95#)
7 Push Press (95#)
7 Burpees
Burpees
22
