Knee Movement & Proper Form during Lunge Exercises

Oftentimes it’s easy to see things as black and white and, as fitness professionals, ideas can be drilled into us where there’s only one way of doing something. But in doing so, it limits our ability to grow with the emergence of new scientific findings and research to learn better technique.
To help dispel common myths and clarify areas often confusing and misunderstood, the following explains the controversy along with most effective and safe way to perform lunges.
It is correct to avoid excessive forward movement of the knee during squatting and lunging movements. It is a myth, however, that you should “never let your knees go past your toes while doing a squat or lunge.”This belief originated from a study that is more than 30 years old (1978 Duke University study that found maintaining a vertical lower leg as much as possible reduced shearing forces on the knee during a squat). The truth is that leaning forward too much is more likely what is truly causing the problem or injury. In 2003, University of Memphis research confirmed that knee stress increased by 28% when the knees were allowed to move past the toes while performing a squat. However, hip stress increased nearly 1,000% when forward movement of the knee was restricted. In addition, in group exercise, the cue “don’t let your knees go over your toes” has long been an effective general rule when trying to teach an exercise to a room full of people with different skill levels, abilities and goals. When a class has a large number of participants it is difficult to help each individual participant with their specific range-of-motion so providing a general “don’t let your knees go past your toes” cue is an effective way of erring on the side of caution for the exercise instructor.
The general pointer while performing a lunge is to try to keep your knees aligned over your second toe so that the knee is moving in the same direction as the ankle joint. However, in reality we often find the knee translating (moving) forward to the toes or beyond in a squat or lunge movement, so there are other things that must be considered. The reason for this can be attributed to the length of limbs (shinbones or tibia/fibula and the thigh bone or femur).
During lunge or squat movements, we should always emphasize beginning the movement by pushing the hips backwards before they lower towards the floor (a term referred to as “hip hinging”). This avoids pre-mature forward movement of the knee by shifting the hips backwards. As we continue to lower our body downward, this creates a healthy hinge effect at the knee, but there comes a time where the knee (tibia) will begin to move forward in order to maintain our balance (keeping our center of mass within our base of support). If you happen to have long limbs, then it is realistic to expect your knees to move forward over or beyond the toes. Any attempt to prevent this will result in either falling backwards or in bad squat or lunge technique which places increased loads into your low back. So, as long as you teach the lunge / squat movement correctly by first initiating the movement at the hip and avoid premature forward movement of the knee, then the fact that the knee may move forward is quite safe.
Part of the reason we lunge is to train movement patterns for our daily activities and when we climb stairs, the knee and torso naturally translate forward in parallel with each other (the torso does not remain vertical) for balance and to propel our body forward and upward. In some instances we’ve seen trainers recommend keeping the back as vertical as possible which is problematic. Our concern is that this vertical technique fails to train the neural pathways and muscles correctly, in the manner it should when you actually climb stairs or step up. Additionally, if you lack adequate flexibility in your hips (considered a mobile joint) when lunging with your torso vertical, then the lumbar spine has to contribute to achieving the mobility you need and in doing so, it will compromise its ability to stabilize the lumbar spine. This could, in fact, increase the loading on your low back.
TIP: Watch your technique in the mirror (side view) the next time you lunge. Place your hands on your hips or in the small of your back and perform your lunge. If you notice any forward tilting in your hips or an increase in the curvature of your low back, you are compromising lumbar stability and I would suggest revisiting your exercise technique.
To help learn the hip-hinge movement, stand and take a broomstick, place it behind your back, holding it with one arm above your head and the other arm places into the curve of your low back. The broomstick should touch the back of your head, the thoracic spine and the sacrum (butt). Keep your legs extended (not locked), push your hips backwards, but try not to bend the knees too much. Try to:
1. Maintain contact with the broomstick against all three points (head, thoracic spine and sacrum).
2. Maintain the same spacing between your hand and your lower back.
This exercise teaches you to initiate your lunge and squat by hip-hinging as opposed to driving your knees forward which places stresses across the knee and patella tendon.

Researched By : Kátia C. Rowlands – Pilates Instructor & Personal Trainer – 082 513 4256

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