As SFMA providers we check the whole body thoroughly from neck to ankles and anything that stands out of place gets checked. Sometimes one part of the body (like the trunk) is involved in multiple movement patterns and that prevents any problems on it being missed. The SFMA is a system that rechecks itself. There is one part of the body that gets checked twice, in two different ways depending what movement was problematic: the ankle.
As previously mentioned in our previous review on the SFMA; it directs clinicians to the area but then lets clinicians use their own expertise to examine the local biomechanical factors in the area. As such, the SFMA checks the ankle as a whole and not subcomponents (e.g. talocrural and subtalar joints). When someone has a problem with single leg stance (SLS), the ankle gets checked for plantarflexion, dorsiflexion, eversion, and inversion. When that same person has a problem with performing the overhead squat, he/she would be checked again for dorsiflexion in a different position.
Everyone can measure their ankle range of motion through our phones! Our app of choice is the clinometer app, or if you have an iPhone, go to the compass app and swipe right to give you the spirit level feature.
For single leg stance (SLS), passive dorsiflexion is checked in a non-weight bearing position and in knee flexion and extension. In this position, we are looking for 20-30 degrees of dorsiflexion. The reason this is checked for SLS, is because of proprioception; the ability to detect movement. For proprioception to detect movement, movement has to be present in the first place – hence checking if dorsiflexion is present is vital; and 20-30 degrees of dorsiflexion is sufficient for single leg stance. This is normally called the open kinetic chain dorsiflexion.
For overhead deep squat, dorsiflexion is passively tested in a loaded half-kneel position as part of the SFMA.
In the loaded position, the ankle joint becomes quite different. The ankle joint becomes compressed and the articulation in the joints becomes a lot more vital. Some clinicians prefer measuring distance from knee to toe, but we use degrees to account for the discrepancy of leg and/or foot length. In this position, we are looking for 40-45 degrees of dorsiflexion, and not more than 5 degrees difference between each ankle. The difference is huge!!
The reason for this is to have a good pattern of overhead deep squat, you would need this much movement in the first place, while not that much is needed for single leg stance. The changes of the joint due to loading also changes the joint mechanics and allow for greater movement increasing that “normal” range for dorsiflexion. This is often called the closed kinetic chain dorsiflexion.
Now, some people would say: “I don’t need that much ankle movement, I only do _______”. Well, the bad news is the ankle works together with the whole body. Even just by walking that last range of ankle movement is vital in walking. In the last range of the stance phase in walking where your hip goes behind you into extension, you need that ankle dorsiflexion.
Without that ankle dorsiflexion you won’t go into that last range of hip extension where the glutes need to fire. So, without the ankle dorsiflexion your glutes would be significantly less active. We know many people have trouble activating or using their glutes – probably worth checking their ankles.
Moreoever, if you have had one or multiple ankle injuries in the past, there COULD be a high possibility that you have been compensating for it in various movements or body parts for a very long time.
In addition, when we check ankle range between both sides, we want to ensure that we do not have more than 4 degrees difference between both sides. I.e. Right ankle 47 degrees, left ankle 40 degrees. In this case, the situtation is also not optimal as there is too large a discrepancy or assymetry for the body.
Taking it one step further, we need that ankle to at the very least, sense motion to the send sensory information up to the brain. As Greg Dea shows in this diagram, the greater the mobility we have, the greater the potential for sensory inputs. This, COMBINED with brain processing, will be expressed in greater efficiency of our movements.
As such as clinicians, we must choose the correct assessment for the right person. Depending on what is necessary one ankle assessment may be more appropriate than the other. If your ankle gets checked twice in different positions, don’t worry! These two tests are different and may show different things which would direct the treatment to different directions as well!
Just to recap, the 2 criteria we have for ankle dorsiflexion is
- Minimum of 40-45 degrees of closed kinetic chain dorsiflexion
- Difference of no more than 4 degrees between sides
As always, thanks for reading!