Excellent question, though it requires a rather lengthy response, so I'll try to be as brief as possible. We will start by getting more specific and by assuming we are referring to the barbell back squat:
Technique dependent: Are we talking about a sumo squat with low bar, or Olympic Style squat with closer stance and higher bar? If that's so,
it all has to do with the individual structure. For instance, individuals with long femurs, short torsos, and short tibias, will have a HARD time achieving anything close to parallel on their own means if attempting an Olympic Style, High Bar Squat. Their builts keep their centers of gravity posterior in relation to their position in the squat during the descending portion. Most attempt to overcome this by flexing the torsos or shifting weight to the balls of their feet.
This can be easily remedied by providing an artifical increase of shin length which shifts the leverage to the favor of the lifter (as in a weightlifting shoe). Or the lifter can switch to sumo stance for which his build is favorable. Many of such people were repeteadly told by "experts" they lacked flexibility or other cockamamie, and no matter what they tried, they never saw success. It is always imperative to adjust the exercise to suit the individual and not the other way around.
Individual Pathology: The barbell back as squat is an exercise that involves axial loading. As such, it requires a healthy trunk structure capable of distributing the axial loading evenly and efficiently. In general, the barbell back squat would be contraindicated for individuals with the following conditions:
- Disc Extrusion
- Congenital Scoliosis
- Spondylosis
- Spondylolisthesis
- Candidates for Vertebroplasty
- Cases of remarkable upper cross sysndrome
- Advanced cases of rotator cuff injuries, the most common involving the supraspinatus.
- Chronic Patellar tendonitis
- SI Joint disorders
Ultimately, it boils down to individualizing the application of the exercise, weighing-in the risk vs. rewards, and more important than anything, making sure it helps the individual achieve both short and long term goals.
As to the knee issues, are we referring to the common buckling of the knees or are there any other issues?
The "
buckling of the knees" has dozens of reasons and one must asses carefully before coming to conclusions. The individual could be flat-footed, or have issues in the subtalar joint, or a leg length discrepancy issue, or hypertonicy in one or several soft tissues involved in adduction of the hip joint, or present hypertonicity at the illiacus, or simply be wearing the wrong shoes (as in running shoes).
It has become quite popular for many to say that "
the glutes are not firing" but more from repeating what it is being said at seminars rather than logical and objective conclusions. Considering that there are 3 gluteus muscles and 6 deep short rotators of the hip, unless an EMG or specific palpation techniques are conducted, just saying "
the glutes are not firing" turns into an exercise of verbal regurgitation rather than a logical conclusion.
Hope this helps. Happy training and good health.
