Sunday, May 11, 2014
Calcaneus neutral- and why the ankle bone really is connected to the hip bone
If you read this blog on a somewhat regular basis, you are aware that I am fascinated by how the body works. This includes an interest with feet and how they impact our movement. Our feet are the first part of our body to receive feedback from the ground. As a result, they are full of mechanoreceptors which send feedback to the brain regarding body position with respect to supporting surface (Kennedy & Inglis, 2002). The ankles and knees provide proprioceptive feedback to the brain which are thought to provide information about joint angle relative to the trunk, linking what happens at the foot and ankle joint to what is happening in our body's center. Interestingly, reduced plantar support (position of the foot) appears to affect stepping reactions to postural perturbations (basically, how you respond to losing your balance). This matters because one of the jobs of the deep core musculature is to maintain stability during walking; this includes making sure the system can recover from large and small perturbations during gait (Stanek et.al, 2011). If our first line of contact with the ground isn't in a position to properly respond to disturbances, how can we expect our deep stability muscles to stabilize when needed? The reverse could also be stated: if the core stability muscles aren't in a good position to do their job, the foot isn't going to be able to do its job. Walking is important, and before we can perform well or move well, we have to be able to walk well and recover from slight changes in the environment that throw off our balance.
The first line of defense is a good offense (or so I'm told) so training the body in a position that addresses foot position is important. First and foremost, I think it is critical to have a spine that is well-organized/neutral/has proper rib cage to pelvis position. This gives the deep intrinsic muscles of the core a chance to do their job reflexively, without conscious activation (and this is what we want. If you miss a step, you do not want to have to actively think, "shoot! Fire transverse abdominis, internal and external obliques, serratus anterior, gluteus maximus!" By then, you will be neatly crumpled on the ground). Further, Moon et.al (2014) point out postural control is automatic and the balance of the body depends on how the center of gravity is maintained by the body's support base; this means small alterations in foot position can change the postural control of the entire body, indicating foot position is important. After the spine position is addressed, a good foot position can be established. I like to spend a little bit of time working with people barefoot, but it isn't necessary. Being barefoot helps a person more readily identify what a neutral position is because of the feedback from the floor, but this can be done in shoes as well. The first thing I like to do is have the person figure out where the center of the foot is located. This means observing normal standing position, rocking forward and back to feel the extremes a few times, and then settling on what feels like the center of the foot to that person. I also have the person rock from left to right and find what feels like 50 percent of the weight in the right foot and 50 percent of the weight in the left foot. This begins to move the person towards a more neutral calcaneus, which simply means the calcaneus on visual inspection will appear centered and you will be able to draw a straight line from the calcaneus up to the back of the knee. This position will allow the arch of the foot to gently lift (if the person has pronated feet) and/or the big toe to begin to engage with floor more actively. It is important to keep the tibialis anterior (the muscle in the front of the shin) relaxed and keep the toes from clawing at the ground. I find it useful to have the person observe how his hips felt in his "normal" standing position and observe any increase or decrease in awareness of the hips in the "new" position. If the person is having a really difficult time with both feet, I frequently use the 1/2 kneeling position demonstrated below to bring awareness to foot position. Doing 5 minutes of standing exercises helps reinforce the position and sensation of the foot and the hip working together. Once in a while, I am unable to improve foot position despite trying a variety of things; when this happens, I refer the client to someone specializing in foot mechanics, such as a podiatrist, for further evaluation. More often than not, I observe improvement in balance and core stability when I incorporate this type of training, and as stated above, walking efficiently is the first step I can take in getting my clients to move well.
Yours in health and wellness,
Video Link: https://www.youtube.com/watch?v=hjVYmzPYv0I
P.S.- For more information about barefoot training, I highly recommend checking out www.evidencebasedfitnessacademy.com
Stanek, J.M., McLoda, T.A., Csiszer, V.J., & Hansen, A.J., (2011). Hip- and trunk-muscle activation patterns during perturbed gait. Journal of Sports Rehabilitation, 20(3), pp. 287-295.
Kennedy, P.M., & Inglis, J.T., (2002). Distribution and behavior of glabrous cutaneous receptors in the human foot sole. The Journal of Physiology, 538, pp. 995-1002