For years we have known and stressed the FACT pushing your knees over your toes during exercises is a terrible, awful thing to do. Since this groundbreaking discovery, knee injuries have been dramatically reduced in all sports, at all levels, all across the globe…
Hopefully you can sense the sarcasm.
While this common knowledge intuitively seems to make sense, unfortunately it has not proven to be true. With the help of skeptics in all fields, many of these myths are continuing to be busted. While anecdotally seeming to make sense, former “facts” about strength training being dangerous for youth, RICE being best for acute injuries, and fat making us fat just don’t have the science to support them.
How did we get here?
We theorized that by utilizing greater ranges of motion in the knee joint, greater stresses would be observed at that joint. The research confirmed these hypotheses over and over again. In turn, many people theorized that by reducing the shin angle, and therefore stress on the knee joint, the healthier the knee would be. Unfortunately this hypothesis has not stood the test of time.
By changing exercise techniques to reduce knee joint function and range of motion, many exercises were modified to become much more hip dominant movements, in turn reducing the stress to the knee joint. Every action has consequences, and while decreasing ankle and knee joint ROM in squats does decrease the stress to the knee joint, we failed to understand the true extent of this simple modification.
Holistic Joint Function
We cannot look specifically at one joint and make claims based on what is best for that joint without understanding how the body functions as a system. Actually we can, however, this is not accurate as athletes don’t move one joint at a time. If we want to look at reducing knee injuries, we need to understand the mechanisms of injury in how these injuries actually occur, from there we can start to understand how dysfunction in different links of kinetic chain influences what is happening at a certain joint, NOT the other way around.
Ankle taping and bracing have been thought of as the answer for reducing ankle sprains, but do these tools really help us to avoid injury or are they simply causing dysfunction in other joints? We need to do a better job of understanding movement and functional anatomy holistically in order to decipher best practices. Though intuitive, the thought that pushing your knee over your toe is bad for you is simply a result of poor understanding of dynamic human movement.
A better intuitive argument…
When an athlete sprints, changes direction, throws, or jumps… their knee consistently ends up in advance of the toe with a positive shin angle in order to redirect ground reaction forces in the right direction. In order to accelerate, force must be applied backwards, this can only happen if a proper shin angle is set up. By taking a step back and looking at movement not just joint angles, it is pretty obvious that if we completely avoid this position in training we may actually be causing more harm than good by failing to train the movements and positions athletes use in sport.
What should you be looking for?
Instead of the amount stress at the knee joint, what should be the biggest concern when the knee comes in advance of the toe is the potential loss of surface area of the foot in contact with the ground. When an athlete accelerates or changes direction, less surface area will not only give them less stable base of support (decreasing ground reaction forces and overall stability) but will also decrease the amount of time they are able to apply that force. This is an important concept to understand as sport is really just multiple variations of deceleration to acceleration; over and over and over again. Additionally, this ability to set proper angles and surface area allows the offensive athlete to create separation from a defender allowing for better positioning for an offensive attack.
As always, intent matters.
A powerlifting style squat can absolutely lead to increases in absolute strength, increasing the potential for greater ground reaction forces. This would be great if strength was the only determining factor in successful sport performance. Continuing on this line of thinking takes us to the insight that if strength is the “end all be all”, powerlifters should be the best baseball / football / soccer / swimmers etc. in the world. However, we know this isn’t the case. Triple flexion ultimately leads to more actualized triple extension. Creating the capacity to generate a positive shin angle while maximizing surface area is a great step to improving overall movement efficiency in the ever changing environment that is sport, and thus should NOT be avoided.