Ankle Mobility and Leg Development

A Wee Bit of Science 

Although research in the field of exercise science is not as glamorous as finding a cure for cancer, it did progress and manage to turn up a few interesting tidbits.

For example, we have known for ages that the type of squat you choose can drastically change muscle demands. A back squat, especially done in the powerlifting style, can recruit the glutes a lot more than the front squat. Scientists explain that this is due to bar placement relative to the center of mass of the body. A good demonstration of this principle is that the same back squat can recruit vastly different muscles whether you use a traditional, more Olympic lifter style or the low bar powerlifter style. 

The choice of squatting style is not always a conscious one though. It depends highly on what you find comfortable. And this in turn depends on your body type and the length of your limbs relative to your torso. If you have a short torso and long legs, like a sprinter, chances are you will be more comfortable in a deadlift or powerlifting squat. Conversely, if you have short legs and a long torso, you will find squatting relatively easy. The length of your segments (legs to torso and shins to thigh) is especially important for lower body movement and their execution. 

Then, there is also the question of foot placement. Having the foot lower on the plate of the leg press or pendulum squat machine will tend to recruit more quadriceps, whereas putting them higher will tend to place more of the tension on the hamstrings and glutes. Those are useful tweaks for the personal trainers looking to optimize a client’s progress or an athlete who wants to make the most of their time under the bar.

The M-Word

So, the length of the levers (aka, the limbs) certainly affects the way one squats and which muscles bear the brunt of the work. However, recent studies have shown that this is not necessarily as set in stone as was once thought. There are ways to at least partially work around this. And what scientists have found is a nightmare for most athletes: yes, the dreaded M-word. It turns out that mobility is the key. Increasing mobility will affect the outcome of both the exercise form and performance and can help in injury prevention.

While this topic goes quite deep and covers a lot of aspects, let us look at ankle mobility in the case of squat as an example of this phenomenon. 

First, let us define a few key terms. Your ankle can do many movements. But mostly, it can extend and flex. The extension, to make matters more confusing, is called plantar flexion. This happens when you point the toes, like a ballet dancer, or when you push your heel off the floor while walking. So, during extension (aka plantar flexion), your ankle forms a more open angle. When you squat down, your ankle forms a sharper angle with your foot and shin. This is called dorsiflexion. It is the same movement as when you bring your toes and the front of your foot up off the floor when your heel is still on the ground. This is the flexion movement of the ankle and it is a crucial factor in the mechanics of the body during the squat movement. Therefore, here are a few ways it can help you.

One Joint to Rule Them All

In 2017, a study done by Fuglsang, Telling and Sørensen (1), revealed that the total range of movement available in ankle dorsiflexion was more relevant to the angle of your trunk leaning forward during squat than the ratios of your limbs relative to your torso. The forward lean of the torso is particularly important for stability during squat and impact the workload of the erector spinal muscles. Lean too far forward, and you might end up kissing the floor. Well, having better dorsiflexion makes it easier to keep the torso more upright during squatting, thus improving form and performance. This is huge and it gives a glimmer of hope to the sprinter-type, long-legged athletes who need to squat to develop more power and speed in their sports. 

This result was further cemented by the results of a study by da Costa et al. in 2021 (2) who measured passive and active ankle dorsiflexion range of motion in relation to lower limb and trunk kinematics during a single leg squat task. They discovered the following:

• Active ankle dorsiflexion range of motion was positively correlated to a reduced trunk forward flexion and pelvis anteversion (aka butt wink)
• Passive ankle dorsiflexion range of motion was associated with reduced internal rotation of the thigh
• There is no association between passive range of motion and active range of motion in ankle dorsiflexion.

These findings correlate well with previous studies on cross-country skiers (3) and a review of landing tasks in relation to ankle dorsiflexion. The more range of motion you have, the more likely you are to have good mechanics in those athletic endeavors.

The message is this: whether you want to squat to have big legs or perform better in the field, you need to increase both passive and active range of motion for dorsiflexion of the ankle. 

Now get that mobility going and squat safe!

References

1. Emil I Fuglsang, Anders S Telling, Henrik Sørensen; Effect of Ankle Mobility and Segment Ratios on Trunk Lean in the Barbell Back Squat; J Strength Cond Res. 2017 Nov;31(11):3024-3033. doi: 10.1519/JSC.0000000000001872

2. da Costa, Guilherme Vinicius & al. Relationship between passive ankle dorsiflexion range, dynamic ankle dorsiflexion range and lower limb and trunk kinematics during the single-leg squat, Gait Posture. 2021 May; 86:106-111. doi: 10.1016/j.gaitpost.2021.03.015. Epub 2021 Mar 8

3. A R Mason-Mackay, C Whatman, D Reid; The effect of reduced ankle dorsiflexion on lower extremity mechanics during landing: A systematic review; J Sci Med Sport. 2017 May;20(5):451-458. doi: 10.1016/j.jsams.2015.06.006. Epub 2015 Jun 15.

4. D Conradsson , C Fridén, L Nilsson-Wikmar, B O Ang; Ankle-joint mobility and standing squat posture in elite junior cross-country skiers. A pilot study; J Sports Med Phys Fitness. 2010 Jun; 50(2):132-8