1st MTP Pain? The Biomechanics of the Big Toe...

Remember the rockers? We have done a series on this in the past. 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. You NEED 50 degrees to do this competently; you SHOULD have 65 degrees. When you don’t, you have a condition called hallux limitus. This could be from a number of reasons, from overpronation in the mid foot, to a bunion, to faulty firing patterns of the muscles which help to descend the 1st ray (the extensor hallucinations brevis, the peroneus longs and the short flexors off the toes). Pretty much, ANYTHING that causes a dorsal and posterior shift of the 1st MTP axis will cause limited forefoot rocker.

So, the question is, “Do you know where 1st 1st MTP pain may be coming from? How familiar are you with the mechanics of that joint?”

Take a few minutes to review it in this video with Dr Ivo Waerlop of The Gait Guys.

#gait, #gaitanalysis, #1stmtp, #forefootrocker, #thegaitguys,

When the going gets rough, we have a tendency to look down...

While working with a patient with runners dystonia the other day, I had one of those epiphanies. I thought I would share it with you here. Here is some food for thought. 

We remember that we have 3 systems that keep us upright in the gravitational plane: The visual system, the vestibular system and the proprioceptive system. As we age, we seem to become more dependent on the visual system, but that is a story we have told before here, and could certainly been expanded on in another post or three... 

The long story today involves the vestibular system. It is a part of the nervous system that lives between your ears (literally) and monitors position, velocity and angular acceleration of the head. There are three hula hoop type structures called “semicircular canals” (see picture above) that monitor rotational, tilt position and angular acceleration, as well as two other structures, the utricle and saccule, which monitor tilt and linear acceleration. 

The vestibular apparatus (the canals and the utricle and saccule) feed into a part of the brain called the floccular nodular lobe of the cerebellum, which as we are sure you can imagine, have something to do with balance and coordination. This area of the cerebellum feeds back to the vestibular system (actually the vestibular nucleii, all 4 of them! superior, inferior, medial and lateral); which then feed back up to the brain (medial, inferior and superior nuclear pathway) as well as down the spinal cord (the lateral pathway) to predominantly fire the extensor muscles.

So, what do you think happens if we facilitate (or defaciltate) a neuronal pool? We alter outcomes and don’t see a clear picture. Most actions in the nervous system are a system of checks and balances, or positives and negatives, and the one the one that predominates, is the one that wins : )

Look at the picture above. Notice the lateral semicicular canals are 30 degrees to the horizontal? If you are standing up and extending your head , that lateral canal becomes vertical and the fluid inside (emdolymph) cannot flow, making it much less useful to the nervous system. Thats why it is hard to stand with your head extended and eyes closed and maintain balance (go ahead and try it, feeling is believing). Conversely, when we flex our head forward(like looking down to see what our footing looks like), we move this lateral canal onto a more physiologically advantageous position, enhancingour balance.  If you are on uneven ground, have an injury or are having issues with proprioception (like many folks do), this actually helps the vestibular system (as well as the proprioceptive and visual systems) to work more efficiently. 

OK, have that? Now one more concept..

So if we look down, we put a slow stretch into our neck extensor muscles, which just happen to have some great postural receptors in them, called muscle spindles, along with mechanoreceptors in the capsules of the joints. So, facilitating (ie. exciting) these receptors, fires more information into our cerebellum, the queen of balance in the nervous system. What do you think happens? Even better balance and coordination! The 2 systems work together, summate to improve movement and balance!

Wow. All this from head position…The key here is to realize what and why you are doing what you are doing....

image from: http://boneandspine.com/what-is-anteversion-and-retroversion/

Femoral versions and torsions?

While searching for something else, we ran across this post. A pretty good lay discussion and explanation about femoral torsions. Technically, versions are NORMAL variations or limb rotations that are within accepted limits and TORSIONS are pathological, when it measures 2 or greater standard deviations from the mean and is considered pathological. Femoral versions are the angular difference between the transcondylar and transcervical axes. The femur is normally anteverted (1). 

We liked the last section talking about how to compensate for them and "acceptable" work arounds and biomechanics. 

https://b-reddy.org/2013/05/09/talking-about-hip-retroversion/

1. Staehli L in: Fundamentals of Pediatric Orthopedics Lippincott Williams & Wilkins, Jun 15, 2015 p 144

What’s up, Doc?

Nothing like a little Monday morning brain stretching and a little Pedograph action.

This person had 2nd metatarsal head pain on the left. Can you figure out why?

Let’s start at the rear foot:

• limited calcaneal eversion (pronation) L > R. The teardrop shape is more rounded on the left. This indicates some rigidity here.
• note the increased pressure at the  medial calcaneal facets on each side with the increased printing
• very little fat pad displacement overall

Now let’s look at the mid foot:

• decreased mid foot pronation on the L. See how thin the line is going from the rear foot to the forefoot along the lateral column? This indicates a high lateral longitudinal arch

Now how about the fore foot?

• increased printing under the met heads bilaterally; L >> R
• increased printing of 1st met head L >> R
• increased printing at medial proximal phalynx of hallux  L >> R
• increased printing of distal phalanges of all toes L >> R

 Figure it out?

What would cause increased supination on the L?

• short leg on L
• more rigid foot on L
• increased pronation on the R

Did you notice the elongated 2nd metatarsals (ie: Morton’s toe) on each foot?

Here is what is going on:

• there is no appreciable leg length deformity, functional or anatomical
• The Left foot is more rigid than the Right, thus less rear, mid and fore foot pronation, thus it is in relative supination compared to the right foot

do this: stand and make your L foot more rigid than the right; take a step forward with your right foot, what do you notice?

• Can you feel how when your foot is supinated
• can you see how difficult it is to have ankle rocker at this point? remember: supination is plantar flexion, inversion and adduction
• Can you feel the weight of the body shift to the outside of the foot and your toes curl to make the foot more stable, so you do not tip to the left?
• now, how are you going to get your center of mass forward from here? You need to press off from your big toe (hallux)

Wow, does that make sense now?

What’s the fix?

• create a more supple foot with manipulation, massage, muscle work
• increase ankle rocker by training the anterior compartment (shuffle walks, lift/spread/reach exercise, heel walking, Texas walk exercise, etc)
• have them walk with their toes slightly elevated
• we are sure you can think of more ways as well!

The Gait Guys. Increasing your gait literacy with each and every post. If you liked this post, tell others and spread the word. If you didn’t like this post, tell us! We value your constructive feedback.

Go ahead and try this at home.

remember last mondays post? (if not, click here). Here is one way of telling whether your (or someone else’s) vestibular system is working. It will also give you an idea of how some people compensate.

Ready?

• Stand up (barefoot or shoes does not matter).

• place your hands resting on the top of your hips with your thumbs to the back (like your Mom used to, when you were in trouble). Your thumbs should be resting on your quadratus lumborum (QL) muscle.

• tilt your HEAD to the LEFT

• you should feel the muscle (ie the QL) under your RIGHT thumb contract

• come back upright

repeat, but this time lean your BODY to the LEFT

• same thing right? Now check the other side.

Everything OK? Everything fire as it should?

Now lets add another dimension.

• slide your fingers down so they are just below the crest of the hip, resting above the greater trochanter (the bump on the side of your upper thigh). This should place your fingers on the middle fibers of the gluteus medius.

• tilt your head (or body ) to the LEFT.

• You should feel the LEFT gluteus medius and the RIGHT QL contract. These muscles should be paired neurologically. When walking, during stance phase on the LEFT: the LEFT gluteus medius helps to maintain the pelvis level, while the RIGHT QL, assists in hiking the RIGHT side.

If everything works OK, then your vestibulospinal spinal system is intact and your QL and gluteus medius seem to be firing and appropriately paired. If not? That is the subject for another post.

The Gait Guys. Helping you to understand the concepts of WHY compensations occur.