Is the "normal foot" normal ?

IF one foot is not normal, the other one cannot be “normal” either.  This is a blog post about symmetry, sort of.

This article just sort of seemed silly to us.

Imagine having a stone in one shoe and walking around in that shoe. Obviously you are gonna alter weight bearing in that shoe to avoid the pain and pressure of the stone. That means that the normal gait cycle of that foot/leg will be distorted somehow, the timed events of the gait cycle will be distorted and even likely the duration of the stance phase, heck, even plantar pressures will be changed.  Thus, the apparently “normal” foot on the opposite side will have an altered loading response and challenge because it will be receiving anything but normal biomechanics from the “stoned” shoe/foot.  Adaptation and compensation will have to occur, and not just in the “normal” foot, the entire body. 

Take another example, a sprained ankle. The brain will abbreviate the painful stance phase and abrupty depart the foot and thus create premature loading on the healthy foot, likely into mid-midstance which is usually met by midfoot strike and catching the body load with the quad thanks to abrupt knee flexion rather than early midstance with glute control during the loading response.  

Thus, if one foot is abnormal, there is just no way the so-called “normal” foot will be unaffected.  As this study suggests, the normal foot will have altered pedobarographic measurements.  Maybe we are missing the point here, but we suppose the words “relatively normal” or an “expected normal” should have been used. Yes, we may be splitting hairs here and discussing a relatively moot point, but our purpose was to just describe that since the two limbs are attached to the same body, if one side is not normal, a compensation has to occur in the other limb.  There is no other option.  We talk more about this concept in podcast 75 which will launch next week.

Shawn and Ivo, the gait guys

The contralateral foot in children with unilateral clubfoot, is the unaffected side normal?

http://www.gaitposture.com/article/S0966-6362(14)00523-2/abstract

Highlights

  • Pedobarographic measurements of unilateral unaffected clubfoot are not same as normal controls.
  • The unaffected foot should not be referred to as normal, nor should it be used as a control.
  • Timings of initiation of stance differ significantly between normal and unaffected clubfeet.
  • Unaffected clubfoot accumulates differences from normal feet due to maturation of gait with age.

Abstract

“Significant differences were identified between the unaffected side and normal controls for the pressure distribution, order of initial contact and foot contact time. These differences evolved and changed with age. The pedobarographic measurements of patients with clubfoot are not normal for the unaffected foot. As such the unaffected foot should not be referred to as normal, nor should it be used as a control.”