One of the fitness commandments or a mistaken myth? Many personal trainers have been taught to avoid letting the knee travel over the toe like the plague but they don’t understand why. Let’s try and shed a little light on the issue.
‘The Knee Over Toe Study’
The origins of the anti-knee over toe argument seem to be held in a research conducted by McLaughlin et al. (1978). The authors concluded that shearing forces acting on the knee were reduced when subjects were instructed to maintain a more vertical shin angle. The problem is not with the work of McLaughlin et al. but the misinterpretation that has followed. The degree of torque reported during squatting exercises is well within the structural capacities of all components in and around the knee joint and therefore do not support the notion that squatting with knees over toes is a dangerous exercise. Furthermore, the study only looked at a two-dimensional model of the knee joint. We have no consideration of the forces acting in other directions or forces acting above, at the hip, or below, at the ankle, where we would expect to observe significant alterations as a consequence.
‘The New Knee Over Toe Study’
The research of Smith and Fry (2003) has been the basis of many writers’ and coaches’ criticism of the knee over toe dispute. The researchers compared back squats where the knee motion was not restricted, and could therefore translate over toe, to squats where a vertical board was placed in front of the lifter’s shins and therefore physically prevented the knee moving over the toe. Their findings seem to support those of McLaughlin et al.; torque forces acting through the knee joint were reduced from 150N.m to 117N.m – a reduction of 22%. This was not without consequence however; torque forces at the hip joint increased from 28N.m to 303N.m – an increase of over 1000%!
What Happens in the Real World?
The most important consideration for any type of training is what you are actually training for. If we’re conditioning an athlete we need to understand what demands their sport imposes on them and then plan the training accordingly. In the majority of sports the knee over toe position is common and we must consider this when we train. There are two paths you can take; a) train them not to get into these positions during their sport, or b) train them to be strong and controlled in these positions. Which would you choose?
What Are You Training For?
As is the case with the whole Olympic vs. powerlifting debate, the right technique for you depends on what you’re training for – not what happens to be in Men’s Fitness at the time. If you’re performing a lunge, for example, then ask yourself why? If it’s for glute development then favour a vertical tibia, if it’s for developing emphasising the quads then let the knee go forwards.
What This Means
So, a brief overview:
· If you let the knee travel over the toes you place a greater emphasis on the quads although increase the stresses acting through the knee joint. It is important to note that the degree of torque reported is well within the proposed structural capacities each component, however, this technique may be contraindicated for those with acute knee problems.
· Knee over toe is required for full knee flexion, such as during a deep squat. Gradual, progressive training in this range should promote more balanced quad development and actually promote long term knee health.
· If you perform exercises with knees behind toes you’re massively increasing the potential to use the glutes and the spine extensors. This maximises biomechanical leverages, loads up the powerful posterior chain and ultimately allows you to lift more weight.
· Keeping the knee behind the toe during squatting may encourage an excessive forward lean which increases the stress placed on the lower back.
There’s nothing inherently wrong with letting the knee travel over the toe – it’s a natural movement pattern. Know what you’re training for and train accordingly.