The Biomechanics of Strength 3: The Squat (Part 1).

The squat is arguably the king of the leg exercises for a number of different reasons. A successful squat from both a bodybuilding and pure strength perspective is reliant on the co-ordinated movement of the muscles that span pretty much all of the joints of the body; not just to create movement but to stabilise the body to prevent injury. When we talk about squatting for powerlifting or strength there are two different bar positions that will influence the way we perform a lift: the high bar position, where the bar sits pretty much on the traps, and the low bar position, where the bar sits lower down the back closer to the line of the rear delts. Whichever position you choose will influence how the muscles of the back, hips and legs are activated, and influence the load that you can lift. We will get onto which type of squat you should potentially use shortly, but for now there’s a few things that need clearing up!

There are a few myths that have long been perpetuated about squatting, but the longest lasting of these is that squatting itself is bad for your knees. It is certainly true that improper technique, especially when combined with poor programming, can lead to knee injuries. However, with proper coaching in terms of producing the correct movement patterns and also in regard to proper progression, then there should, assuming there are no underlying structural issues, be no issues with squatting heavy or high volume whatever your training goals. Before we go any deeper, it is important to note that there are many variations on ‘good’ squat technique that will depend on your own structure, dominant muscle groups and restrictions on range of motion, which may not necessarily be caused by poor mobility. 

Although the knees are under increased amounts of shearing (think sliding of the joint surfaces across each other as opposed to compression squeezing the joint together) during very deep squatting, the structures within the knee have a ‘locking-in’ effect at high degrees of knee flexion (when the knee is more bent) which helps to stabilise the knee joint to a greater extent than at lower knee flexion angles (when the knee is straighter) with maximum moments and quadriceps activation being generated at around 80-90 degrees of knee flexion. This does not increase at deeper squatting positions, suggesting that squatting deeper than this would not illicit any increased quadriceps development. Deep squats do however recruit to a greater extent the glutes and calf muscles so depending on goals, this should be considered. This also highlights that to optimise quadriceps development, you need to be squatting to around parallel. Partial or half reps will not be fully activating your muscles to their full potential and you will be missing out on muscle growth.

Another typical piece of squatting advice that is commonly given is to not let the knees drift in front of the toes. Although this ‘drift forward’ has the potential to increase shearing forces within the knee, it is impossible for some people, particularly those with longer femurs, to place the hips and spine in an optimal position to provide support and added power to the lift. One helpful cue for the lift is to consciously sit back into the lift and resist pushing the knees forward; this will reduce unwanted forces within the knee and reduce risk of injury. That being said, many of the world’s best squatters let their knees drift way in front of their toes with no issue what-so-ever, therefore it is likely that the amount of ‘drift’ you can get away with is going to be determined by individual variations.  It should be becoming increasingly clear at this point that the technique for a squat (and you guessed it, for pretty much every lift) will vary slightly from person to person and good strength coaches are excellent at analysing a person’s structure and natural strong points, and are a valuable tool to help you get the most out of every lift.

That being said, there are probably some general rules that you should pretty firmly stick to when squatting to make sure you stay injury free. If we are looking at a person squatting from the front, the knees should remain in a relatively fixed position with no drift or dipping inwards of the knee throughout the entire range of motion. This is one of the most common squat mistakes that you will see in the gym, and possibly the most dangerous in terms of long term knee problems. If this takes place, a conscious effort should be made to keep the knees pushed outwards. If this cannot be maintained, then the weight needs to be lowered until it can and supplementary exercises to strengthen the muscles of the hips is also a great addition.

Oh, and in case you were wondering what the most common squat problem from a powerlifting perspective is, it is not reaching adequate squat depth. One key piece of advice for those looking to compete in powerlifting is to get yourself an honest spotter who will make sure you are hitting depth (crease of the hips below the line of the knee). That concludes part one of this ‘epic’ journey into the squat. Now we have focused on the basics of the squat and some general safety guidelines, in part two, we are going to focus on how each joint involved in the squat can influence its performance and how we can identify and overcome some common issues that might limit our ability to squat properly.

Thanks for reading,

Team TTC.