Abdominal Activity and Gait

We came across this cool study today, after a well educated patient asked about abdominal activity during gait.

Here is the bottom line:
low level activity in the rectus abdominis and external oblique throughout the gait cycle, more concentrated activity of the internal oblique at initial contact/loading response (heel strike).

This makes sense, since the external oblique occupies more real estate and has a larger cross sectional area; it most likely has a role in stabilization both in rotational like emoticon planes as well as the saggital plane (Z). Perhaps the action of the internal oblique at initial contact is to assist in external rotation of the pelvis on the stance phase leg, as the the opposite leg goes into swing?

“Cluster analysis identified two patterns of activity for the internal oblique, external oblique and rectus abdominis muscles. In the lumbar erector spinae, three patterns of activity were observed. In most instances, the patterns observed for each muscle differed in the magnitude of the activation levels. In rectus abdominis and external oblique muscles, the majority of subjects had low levels of activity (<5.0% of a maximum voluntary contraction) that were relatively constant throughout the stride cycle. In the internal oblique and the erector spinae muscles, more distinct bursts of activity were observed, most often close to foot-strike. The different algorithms used for the cluster analysis yielded similar results and a discriminant function analysis provided further evidence to support the patterns observed”

Clin Biomech (Bristol, Avon). 2002 Mar;17(3):177-84.
Abdominal and erector spinae muscle activity during gait: the use of cluster analysis to identify patterns of activity.
White SG1, McNair PJ.

In our ever popular; ask the Docs, here is another question from a reader

Transverse Arch

How would one go about “rebuilding” their transverse arch? The latter is pretty much convex. This also accomapnied by very tight long toe extensors (as evidenced by their tendons being very prominent at the top of my foot and my toes being curled at rest) and have suffered on and off from Morton’s neuroma. The ball of my shoes (right in the middle) is where the insoles of my shoes see the most wear. It’s not a huge concern of mine, but I would like to deal with this. I’ve suffered several ankle injuries (as a basketball player) and although I’ve tried orthotics in the past (for the neuroma), I’ve relied mostly on minimalist footwear (except when playing ball of course…). I know some rehab would be in order and would likely work. I’ve “reconditoned” my big toe abductors in the past and can even cross my second to over my big toe, so am just looking for some direction.

Thanks

E

 

Hi E

As you probably are aware, there are 3 arches in the foot: the medial longitudinal (the one most people refer to as the “arch”, the lateral longitudinal (on the outside of the foot) and transverse (across the met heads).

Your collapsed transverse arch seems like it may be compensated for by a rigid, probably high medial and lateral longitudinal arches. This creates rigidity through the midfoot (and often rear foot) and creates excessive motion to try and occur in the forefoot. Depending on how much motion is available, this may or may not occur.

You don’t seem to be able to get your 1st metatarsal head to the ground to form an adequate tripod, so you are trying, in succession, to get some of the other, more flexible ones there (thus the wear in the “ball” of the foot you noted). This results in increased pressure, metatarsal head pain, possibly a bunion and often neuromas.

From your description, you actually have very weak long toe extensors (and possibly some shortening) which is causing the prominence of the tendons, along with overactivity of the long flexors (and thus the clawing) in an attempt to create stability. I am willing to bet you have tight calves as well (especially medially, from overuse of the gastroc to control the foot) and limited hip extension with tight hip flexors.

The foot tripod exercises are a great place to start, as well as heel walking with the toes extended and walking with the toes up (emphasizing extension, which counteracts the flexors). Stay away from open back shoes and flip flops/sandals; continue to go barefoot and get some foot massages to loosen things up. Maybe use one of those golfballs to massage the bottom of the foot when you get off the course and get some golf shoes that aren’t quite so rigid.

Ivo and Shawn. Still middle aged. Still bald. Still good looking….