Do Front Squats Increase The Risk Of Achilles Tendon Injury?
We love them as much as we hate them.
Nonetheless, none of us dare to question their effectiveness for building lower body strength, power and improving performance in almost all sports.
The back squat, where the barbell is placed on the upper back, is the most common form of strength training squat exercise, but some also opt for the ‘front squat’, where the barbell is placed in front of you whilst squatting (using a variety of grip techniques).
Little is known about the front squat, and on the surface it can be easy to assume it’s simple just another position of a barbell squat, but the mechanics are in fact entirely different. As a result of this, the outcomes of the front squat are in fact different to a back squat.
The biomechanical differences between front and back squat
To the human eye, if quickly glancing at the different types of squats, they look very similar. A barbell is placed at approximately shoulder level, horizontally, the feet placement are slightly less than shoulder width with a slight outward flare.
The difference in the biomechanics of each squat does not actually appear until the squat motion begins.
When you have a barbell on your back, and you squat down, you have the ability to lean (slightly) forward without losing balance, because the weight behind you will keep the equilibrium.
This is not the case with the barbell in front. Leaning forward in this instance will be further aggravated by the weight of the barbell, and there is higher chance of losing balance.
Due to this change in how the spine will lean, all other joints, including the hip, knees and ankles, will have force applied through them differently, also. This is demonstrated in the illustration below:
The effect front squat has on the Achilles tendon
The back and front squat look almost the same, but they produce very different forces through the body.
Firstly, it’s worth noting that a front squat requires the body to be unusually upright whilst having a significant amount of weight loaded from the top half of the body.
If you can practice, for demonstration purposes, holding a heavy backpack close to your chest and then squatting down, you will feel that your back cannot help much with holding the bag upright. Because the bag is in front of you, leaning forward does not help during the squat motion.
However, leaning forward with a backpack being on your back as you would normally see on someone will help hugely. This is because the weight can ‘lean’ on your entire spinal musculature. That’s a huge amount of support!
That’s why you’ll see children with heavy backpacks on their back walking with their upper body slightly leant forward. They are engaging their entire back to prevent the backpack pulling them back and falling over (to take this example to an extreme).
You may think that because of this, injury risk is higher with front squats in the knee and ankle.
Surprisingly, the answer is not so clear.
In fact, a study by the University of Lancashire specifically looking at the effect of front vs back squat on the Achilles tendon found that the load and pressure is actually less during the front squat as opposed to the back squat.
The reason for this is very simple and logical.
During a front squat, there is an increase in the dorsiflexion of the Achilles tendon (the motion of pointing toes toward yourself). ‘Load’ is defined in this context as the plantar flexor movement (opposite of the dorsiflexor movement) divided by the moment arm (the angle of the ankle joint during motion).
As explained earlier, during a back squat, your back is significantly more likely to bend forward, to support the weight, and due to the fact there is a weight on your back almost causing you to lean forward.
Due to this, your knees also tend to lean more forward during a back squat.
As a result of this, you will naturally feel more dorsiflexion of the ankle (the motion of pointing toes toward yourself).
This motion, specifically, the dorsiflexion, causes a lengthening of the Achilles tendon, and with the weighted.
As the studied showed using this graph:
The above image (specifically the bottom chart) shows that the front squat reduces the load into the Achilles tendon.
This led the researchers the conclude:
“Given the proposed relationship between the magnitude of the load experienced by the Achilles tendon during dynamic activities and Achilles tendon pathology, it is suggested that those at risk of developing injuries related to the Achilles tendon may attenuate this risk through more frequent utilisation of the front squat in their training.”
This is very encouraging for those who enjoy varying between their squats.
At our Crawley physiotherapy clinic I love to recommend a variety of different exercises, especially if the research supports a movement that could reduce the chance of injuries.
Squats are an important part of many rehabilitation programmes and it helps to keep the motivation and enjoyment high during the recovery periods from an injury.
Front squats allow for a variation of a staple exercise that is both safe, engaging, effective and this study suggests it could be especially useful for those recovering from any Achilles tendon injury.
Physiotherapist BSc MCSP HPC
Founder and Principal Physiotherapist at Tavistock Clinic.
HCPC Registration Number PH97986
CSP Registration Number 089576