#1st ray

[almightyramtha]

Inktober 22, 23, 24

Allemagne/Ahriman

1st Ray

Magic Pot

[thegaitguys]

The EHB....In all its glory...

The extensor hallucis brevis : An overlooked "miracle worker"

Look at this beautiful muscle in a foot that has not yet been exposed to hard planar surfaces and shoes that limit or alter motion!

The Extensor Hallicus Brevis, or EHB as we fondly call it (beautifully pictured above causing theextension (dorsiflexion) of the child’s proximal big toe) is an important muscle for descending the distal aspect of the 1st ray complex (1st metatarsal and medial cunieform) as well as extending the 1st metatarsophalangeal joint. It is in part responsible for affixing the medial tripod of the foot to the ground.  Its motion is generally triplanar, with the position being 45 degrees from the saggital (midline) plane and 45 degrees from the frontal (coronal) plane, angled medially, which places it almost parallel with the transverse plane. With pronation, it is believed to favor adduction (1).

It arises from the anterior calcaneus and inserts on the dorsal aspect of the proximal phalynx. It is that quarter dollar sized fleshy protruding, mass on the lateral aspect of the dorsal foot.  The EHB is the upper part of that mass. It is innervated by the lateral portion of one of the terminal branches of the deep peronel nerve (S1, S2), which happens to be the same as the extensor digitorum brevis (EDB), which is why some sources believe it is actually the medial part of that muscle. It appears to fire from loading response to nearly toe off, just like the EDB; another reason it may phylogenetically represent an extension of the same muscle (2-4).

Because the tendon travels behind the axis of rotation of the 1st metatarsal phalangeal joint, in addition to providing extension of the proximal phalynx of the hallux (as seen in the child above), it can also provide a downward moment on the distal 1st metatarsal (when properly coupled to and temporally sequenced with the flexor hallicus brevis and longus), assisting in formation of the foot tripod we have all come to love (the head of the 1st met, the head of the 5th met and the calcaneus).

Why is this so important?

The central axis of a joint (sometimes called the instantaneous axis of motion) is the center of movement of that articulation. It is the location where the motion will occur around, much like the center of a wheel, where the axle attaches. In an articulation, it usually involves one bone moving around another. Lets look at an example with a door hinge.

A hinge is similar to a joint, in that it has parts with is joining together (the door and the jamb), with a “joint” in between, The axis of rotation of the hinge is at the pivot rod. When the door, hinge and jamb are all aligned, it functions smoothly. Now imagine that the hinge was attached to the jamb 1/4” off center. What would happen? The hinge would bind and the door would not operate smoothly.

Now let’s think about the 1st metatarsal phalangeal joint. It exists between the head of the 1st metatarsal and the proximal part of the proximal part of the proximal phalanyx. Normally, because the head of the 1st metatarsal is larger than the heads of the lesser ones, the center of the joint is higher (actually,almost 2X as high; 8mm as opposed to 15mm). We also remember that the 1st metatarsal is usually shorter then the 2nd, meaning during a gait cycle, it bears the brunt of the weight and hits the ground earlier than the head of the 2nd.

The head of the 1st metatarsal should slide (or should we say glide?) posteriorly on the sesamoids during dorsiflexion of the hallux at pre swing (toe off). It is able to do this because of the descent of the head of the 1st metatarsal, which causes a dorsal posterior shift of the axis of rotation of the joint. We remember that the head of the 1st descends through the conjoined efforts of supination and the coordinated efforts of the peroneus longus, extensor hallucis brevis, extensor hallucis longus, dorsal and plantar interossei and flexor hallucis brevis (which nicely moves the sesamoids and keeps the process going smoothly)(1, 5).

Suffice it to say, if things go awry, the axis does not shift, the sesamoids do not move, and the phalanyx crashes into the 1st metatarsal, causing pain and if it continues, a nice spur you can write home about!

Needling this muscle is easy, as it is very accessible on the dorsum of the foot and due to the decreased receptor density, is not too uncomfortable. I like to needle the peroneus longus and short flexors as well, as they all have the function of lowering the head of the 1st ray. Check it out in this quick how to video.

1. Michaud T: Human Locomotion: The Conservative Management of Gait Related DisordersNewton Biomechanics; First Edition 2011

2. https://www.physio-pedia.com/Extensor_Hallucis_brevis

3. http://www.wheelessonline.com/ortho/extensor_hallucis_brevis

4. Becerro de Bengoa Vallejo R., Losa Iglesias M.E., Jules K.T.  Tendon Insertion at the Base of the Proximal Phalanx of the Hallux: Surgical Implications (2012)  Journal of Foot and Ankle Surgery,  51  (6) , pp. 729-733.

5. Zelik, K.E., La Scaleia, V., Ivanenko, Y.P. et al. Eur J Appl Physiol (2015) 115: 691. https://doi.org/10.1007/s00421-014-3056-x

[zero2zedgaming]

Final Fantasy VII - Random Battle 9

Random battle from Final Fantasy VII, this battle is during the Mako Reactor 1 bombing mission and features Cloud and Barret ambushed by a pair of Grunts and a Mono Drive.

1: Intro 00:00

2: Battle - Grunt x2 & Mono Drive 00:13

3: Outro 01:10

For the full 3+ hour video of random battles from Final Fantasy VII that this video is from check out this video. 

[zero2zedgaming]

Final Fantasy VII - Random Battle 11

Random battle from Final Fantasy VII, this battle is during the Mako Reactor 1 bombing mission and features Cloud and Barret going up against a Grunt and two 1st Ray's.

For the full 3+ hour video of random battles from Final Fantasy VII check out this video. https://youtu.be/aPjOdb4VoRQ?si=sr3isQNnKJBYK2nz

[thegaitguys]

"I'll plead the 1st . . . ."   More foot geek stuff from The Gait Guys.

The 1st Ray that is!

The "1st ray" consists of the 1st metatarsal and the medial cunieform, essentially the long bones associated with the big toe. It is a functional unit we often refer to when discussing foot biomechanics.

You have heard us speak of the 1st ray needing to descend to form the medial tripod of the foot (tripod review: head of 1st metatarsal, head of 5th metetarsal, center of calcaneus). This action depends to some degree on the competency of the peroneus longus, which attaches from the upper lateral fibula and the associates interosseous membrane; curves around the lateral malleolus, crosses under the foot and attaches to the base of the 1st metatarsal and medial cunieform. The tibialis posterior is supportive to this action. This action is opposed (or modulated, for every Yin there is a Yang; it's all about balance) is the tibialis anterior, which attaches to the top of the base of the 1st metatarsal and 1st cunieform.

As a result, 1st rays can be elevated or depressed. (here is a latin term to impress your friends with: Metatarsus Primus Elevatus, or elevation/dorsiflexion of the 1st ray/metatarsal). Clinically, we see more that are elevated, resulting in a faulty (collapsing) medial tripod of the foot. The important thing is isn't necessarily its position, but rather its flexibility. The inflexible ones (isn't it always?) are the problem children, because they result in altered (notice I didn't say bad) biomechanics. The further we move from ideal, the closer we seem to move to some compensation pattern. The flexible ones are still a problem but we can control and dampen their rate of flexible collapse.

Generally speaking, a plantar flexed 1st ray that is rigid, has a tendency to throw your center of gravity (an often your knee) to the outside of the foot tripod (think of a rigid cavus foot) and a dorsiflexed to the inside of the foot tripod. Sure, there are LOTS of other factors, but we are talking in generalities here.

Look carefully at the images above and note the position of the 1st metatarsal heads. In the top set, the 1st is depressed (or plantarflexed). In the bottom set they are elevated (or dorsiflexed). Cool, eh? 

NOTE: please refrain from using the term "dropped metatarsal". Nothing gets dropped, it is correctly stated as plantarflexed (rigid or flexible).

Be on the look out for these on your clinical exam.

Ivo and Shawn. Bringing you one step closer to foot geekdom each day!

copyright 2012 The Homunculus Group/The Gait Guys. All rights reserved. If you rip off our stuff, you will be plagued with the curse of Toelio.....

[thegaitguys]

Athlete with Plantar Fascitis

Gentlemen,   I have enjoyed your blog tremendously.  My inner mechanics geek motivated me to read all the blog posts, and go through the Youtube videos as well.  Fascinating stuff.   My reason for writing, however is more desperate.   I have an athlete with a problem, and hope you might provide some guidance.  She is experiencing what has been diagnosed as plantar fasciitis, with her pain on the medial side of her calcaneus - roughly 2 inches forward of her achilles, and about a half inch up.  MRI was negative for a calcaneal fracture.   She's taken several months off, and had the site injected, but any return to running brings her pain back.  It's her mechanics that might catch your interest;  she has what a doctor once referred to as 'an Equinus Deformity", essentially running completely on her forefoot.  She had heel contact when walking, but is completely on the balls of her feet when racing or training.  Her injury history to this point has been minimal, with only a minor adductor issue for a day or two in her background.  She has been told her options are injection (tried, helps for only a short time) or surgery.  Humbly, is there anything we can do to help her overcome this?  I am convinced there is an underlying mechanical issue, but her somewhat nontraditional running style leaves me with few ideas.  Any suggestions would be worth their weight in gold.       Sincerely,    Girls XC/track coach  

Dear Track Coach

Thank you for the Kudos and we are glad you have an "inner mechanics" geek as well .

We are sorry to hear about your athletes recalcitrant problem. It was astute observation on your part regarding her gait. Given the history you have provided, what has already been done, and the description of what you see, please understand that our opinion is limited, without the opportunity to examine her (which we would be glad to do; we have offices in the Chicago, IL suburbs and West of Denver, CO). Video would be helpful in the future as well, as we are not sure she has a true talipes equino varus foot or it is merely describing the attitude of the foot while running.

It sounds like she may have a rigid foot and a forefoot varus deformity. This would parlay with the "equinis" description.

A forefoot varus is when the forefoot to rearfoot relationship is such that the forefoot is inverted with respect to the rearfoot. This causes increased torque on the plantar fascia, as the forefoot lands on the outside of the foot and the medial side of the foot immediately descends: this must be controlled some how: either through flexion (downward motion) of the 1st metatarsal and cunieform (ie 1st Ray complex) provided adequate range of motion is available; the other scenario is that there IS NOT adequate range of motion of the 1st ray available and the knee collapses medially to bring the 1st ray down to the ground. A third possibility (most likely) is that it is a combination of the two.

The fix lies in the etiology: follow the mantra: skill, endurance, strength. Insuring the foot has adequate range of motion and is able to control it (skill), the appropriate endurance of the muscles to carry out the job (endurance) and the foot intrinsics have the cross sectional area needed to do the job (strength).

1. Does the athlete have a adequate foot tripod and are they able to keep all 3 legs of the tripod on the ground with the knee comfortably over the 2nd metatarsal? see a video here

2. does the athlete have enough muscular control of the lower extremity to ensure proper mechanics (foot intrinsics, knee motion, hip motion) ?

3. Is their running gait appropriate for their anatomy and any physical limitations? we have numerous posts covering many different gait scenarios on the blog, as well as on our youtube channel.

Again, without an exam, pictures or video, the exact diagnosis and fix is difficult. Thanks for the opportunity to respond.

The Gait Guys