Strengthening Control Foot Dynamics?

By Dr. Emily Splichal August 20, 2012 Category: Fitness & Your Feet

I often get asked if this training technique truly is effective at
correcting foot function.  Conceptually it makes sense that if I
strengthen my hip external rotators, I should be able to resist the
internal rotation force caused by my everting rearfoot.  Of course as
a podiatrist, we need to see the research to support such belief.

Consider this. In a foot that has excess rearfoot eversion, there is
an associated increase in tibial internal rotation.  Depending on the
hip strength, this tibial internal rotation will be countered with an
external rotation force from the posterior fibers of the glueus
medius.  However, in cases where the client has weak hip external
rotators, the internal force of the tibia will cause femoral internal
rotation and an associated anterior tilt of the pelvis.

If we were to strengthen the posterior fibers of the gluteus medius,
therefore increasing the external rotator strength, can we resist this
internal rotation force initiated from the foot?

A 2007 study by Snyder et al. evaluated the effectiveness of 6 weeks
hip external rotator strengthening on rearfoot kinematics during
running.   In the study 15 women with moderate pronation (average
calcaneal eversion 5 degrees) participated in single leg stance, hip
external rotator exercises three days a week for 6 weeks.  After the 6
weeks, women showed significant increase in hip external rotator
strength, decreased knee abduction and decreased rearfoot range of
motion and velocity at heel strike.

Although the women did not have excessively over-pronated foot type,
this study suggests the effectiveness of proximal hip strengthening on
distal foot function.   One finding of particular interest was the
decrease in rearfoot  eversion  velocity after the 6 weeks of hip
strengthening.  We know that the posterior tibialis muscle plays an
important role is decelerating midstance pronation, and has been shown
in previous studies that weakness and fatigue of this muscle is
associated with increased rearfoot pronation and associated internal
rotation of the tibia.

This study suggests gluteus medius strengthening  is an effective
technique for controlling dynamic rearfoot kinematics.  I promote
barefoot balance training, as it integrates  (1) single leg stance hip
strengthening (which has been shown to have the highest muscle
activation) and (2) you will feel the trochanters movebarefoot
training (which has been shown to
increase foot intrinsic muscle strength and plantar cutaneous
mechanoreceptor activation).  For athletes and runners who experience
posterior tibialis fatigue and associated knee pain after prolonged
exertion, you may want to consider incorporating barefoot balance
training to improve rearfoot kinematics.

References:

O’Connor, K. et al. The role of selected extrinsic foot muscles during
running. Clin Biomech, 2004. 19: 71-77.

Snyder, K. et al. Resistance training is accompanied by increases in
hip strength and change in lower extremity biomechanics during
running.  Clin Biomech, 2007. 24- 26-34.

Your Body will Work as a Whole

The body always works as a whole. An example of this relationship is
the hip has to pronation and supination of ankle. Place your finger
tips on both great hips while you are standing. Now pronate
both ankles and you will feel the trochanters move backward into
external rotation. If you really want to play this, pronate one ankle
and supinate the other ankle. You should now notice that the hip on
the side of pronation lowered, and the hip on the side of
supination raised.

This is how foot and ankle problems can mimic short or long legs when
they are in a patho-mechnical relation. Of course it also works vice versa.


Hyunsuk Oh, DC, CCEP, CKTP, ART®, GT®

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Hyunsuk Oh, DC, CCEP, CKTP, ART®, GT®

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