Forefoot Rocker and Premature Heel Rise:
Remember the rockers? We did a series on this a few weeks ago. Remember there are three: heel, ankle and forefoot. We are going to concentrate on the forefoot today. As a reminder, forefoot rocker occurs at the 1st metatarsal phalangeal joint (big toe knuckle) as the tibia progresses over the forefoot during forward movement. There are 4 things that SHOULD happen at this point to ensure the heel comes up :
1. continued forward momentum of the body
2. the posterior compartment (primarily the gastroc/soleus group and tibilais posterior) contract to accelerate the rate of forward limb movement.
3. passive tension in the posterior compartment muscles
4 the windlass effect of the plantar fascia (see diagram)
Watch this slow motion video and what do you see? You should see some midfoot collapse and premature heel rise, especially on the right foot. Did you notice the little “bounce” in his step? How about the subtle adduction of his heel, L > R? Watch it again until you see it. (The bounce is generated by the premature heel lift and premature firing of the calf compartment muscles. Normally the body mass is further forward of the heel rise event, and thus contraction of the calf generates a more forward directed vector, however, when the heel rise is premature the body mass is still somewhat over the foot. Thus, if the calf were to fire at this moment, it would cause a vertical body mass movement vector. When this occurs bilaterally these clients will have a very “bouncy” vertically oriented gait strategy. This is very inefficient gait when it occurs. Plus there is a dramatic reduction in the pronation phase of gait, so shock absorption is severely reduced.)
Does he have forward progression of the body mass? Yes
Do you think the posterior compartment is actively contracting? Probably too much. Remember the medial gastrocnemius adducts the heel at the end of terminal stance to assist in supination.
Does there appear to be increased passive tension in the posterior compartment? Yes, it appears to be the case !
How is his windlass mechanism? Good but not good enough. (see our next blog post regarding the Windlass)
Premature heel rise… Coming to a midfoot overpronator and people with loss of hip extension near you.
Telling it like it is. We are the Gait guys…..