Top 100 Biomechanical Guideline #55: Develop the attitude that supination is always "evil" and pronation may not be so bad

When doing gait evaluation, contact phase supination where the heel rolls out (excessive supination or also called lateral instability) is always bad, whereas pronation can be bad or good. With so many shoes over controlling the foot, eliminating all of the pronation needed for shock absorption and adaptability with the ground, no wonder some of the running community is going towards less and less stable shoes. 

Supination---bad

Pronation---good at times, bad at times

Top 100 Biomechanical Guideline #63: Extrinsic Rear Foot Posts can be Modified in Many Ways

The attachments in the heel area of functional orthotic devices are called posts (extrinsic rear foot posts to be exact). They help stabilize the foot and can play a minor or major role in the orthotic device. They can also be modified many ways to limit motion, create motion, change positioning of the body (called canting), and be accessorized (here with a heel lift for short leg syndrome). 

This is the normal way I look at an extrinsic rear foot post, from the back. The post holds the correction prescribed in the orthotic device. It also acts like a heel lift to gentle push the body weight forward. Most arch supports hold the body weight too far back, so the post can help can your body weight forward.

When you deal with the biomechanics of a patient, you are always trying to correlate injury to function. When you have major complexities working together, things can get exciting in the biomechanics and orthotic world. For example, when trying to treat a patient with shock absorption issues, with a short leg, with excessive pronation, yet overly supinates with any arch support, and has a scoliosis with pelvic asymmetry, changes in post positioning, or post motion can make or break your treatment. 

Top 100 Biomechanics Guideline #51: Shoe Modifications may be Necessary to Increase Flexibility

This diagram demonstrates the normal foot motion I observe in gait as the foot moves. This post emphasizes the SMOOTH TRANSITION FROM HEEL TO TOE  vs  Sagittal Plane Blockade which can cause many problems.

Cuts are made into the midsole of the shoe in the ball of the foot area  (metatarsals)  to help patients move easily through their shoes. The cuts are normally 1/4 inch apart, normally 5 in number, and do not go all the way through the bottom of the shoe, and do not go all the way to the medial or lateral sides of the shoe.

There are many painful situations that require wonderful, thick, padding in the front of the shoe, and great flexibility as well. Most shoes that have a lot of forefoot padding can cause some reduction in the ability of the patient to move freely and comfortably through their foot from heel contact to push off. When this heel to front motion is blocked, even slightly, stress can be taken up in the knees, hips, and low back. We thick just flexing the ball of the foot a couple of times will do the trick. But, the EVA material commonly used for the midsole tends to stiffen up only minutes after you stop wearing them. 

Biomechanics experts have coined the term "Sagittal Plane Blockade" to reflect this blockage of motion from heel to toe. Remember my earlier post on the components of foot motion that should normally be there as you walk or run. Your foot motion should be smooth, non-jerky, centered at push off between the 2nd and 3rd toes, or the 2nd and 1st toes. 

Top 100 Biomechanical Guideline #44: Understand the Damaging Effects of Forefoot Varus Support

The cast above show the typical Root Balance Technique of  Forefoot Varus Feet. With this foot type, the maximum support is under the first metatarsal. Remember you need first metatarsal plantar flexion for normal propulsion. Having possibly too much pressure under the first metatarsal can:

1. Dorsiflex the First Metatarsal with gradual development of bunions or hallux limitus/rigidus
2. Dorsiflex the First Metatarsal causing Apropulsive Gait (not allow normal first metatarsal plantarflexion.
3. Dorsiflex the First Metatarsal causing Sagittal Plane Blockade with Hip/Low Back Problems
4. Dorsiflex the First Metatarsal producing Lateral Instability with compensation.

Top 100 Biomechanical Guidelines #43: Sagittal Plane Blockade may Occur with Everted not Inverted Heel Corrections (Forefoot Varus Correction could cause Blockade of Motion)

These are Forefoot Varus Casts. Uncorrected then lean inward and the arch would flatten and foot pronate. Correction of this foot has always been a dilemma for biomechanical experts. If you fully straighten this foot, the heel goes straight up and down, but the correction places too much support under the inside front of the foot (near the big toe). Drs Sheldon Langer, Justin Wernick, and Howard Dannenberg were the first podiatrists to discover and explore how potentially dangerous this support was. Too much pressure under the big toe area (first metatarsal) could block the normal motion of the foot from heel to toe and cause problems in the foot, ankle, knee, hip and back. They coined the phrase "Sagittal Plane Blockade" to describe this problem. When you walk with your orthotic devices, do you feel like you can easily move across them? This is a question I try to ask all my patients, and try to observe in gait evaluation. It is vital for normal foot function and to avoid symptoms.

     When I measure foot biomechanics, and I take a cast capturing over 5 degrees of forefoot varus, I know I will have issues for compromise to deal with. Fully correcting the total amount of forefoot varus would probably lead to problems related to Sagittal Plane Blockade. Correcting less than total could lead to the continuation of symptoms related to the pronation I was trying to treat in the first place. For the biomechanical experts out there, if you sacrifice some of the forefoot varus correction with a modified Root Balance Technique consider Kirby Skives, Inverted Pours, or BiAxial Wedging to get your pronation control without producing Sagittal Plane Blockade. You are basically transferring support from the front of the arch to the back of the arch.

Top 100 Biomechanical Guidelines #42: Root Balancing Forefoot Valgus maximizes Lateral and Metatarsal Support

A Forefoot Valgus Cast sits Inverted on the countertop.

The edge of the box is vertical demonstrating the Inverted heel position of the cast.

When this type of cast is Root Balanced, the lateral column and the metatarsal arch gets great support.

 Positive Cast with Inverted Heel noting forefoot valgus type foot

 Heel is set to vertical before plaster poured into negative cast

 Negative casts being set for pouring

 Once the plaster dries, the cloth is removed. The inverted heel position is seen.

 The forefoot is balanced initially with a nail.

 Plaster is used to make a platform for balancing.

 The platform will make a dramatic lateral and metatarsal arch.

 Here the lateral arch is demonstrated.

Here the metatarsal area is shown lower than the platform, which will make a great metatarsal arch within the plastic.

Top 100 Biomechanical Guidelines #41: Root Balancing Forefoot Varus may have to be a compromise (esp. over 5 degrees)

      Here are two positive casts of a patient with forefoot varus. The area under the first metatarsal is marked where problems with the Root Balance Technique can occur. If you use the Root Balancing Technique with forefoot varus, you run the risk of jamming the first metatarsal not allowing crucial first ray plantarflexion for propulsion.

     The line running obliquely across the foot represents the longitudinal axis of the midtarsal joint. It is important for proper foot function that the weight of the foot passes laterally to this line, keeping both midtarsal joints pronated in midstance and propulsion. When supporting the forefoot varus deformity, the Root Balance Technique can produce too much pressure under the first metatarsal causing long axis supination interfering with proper foot function.

     This has been a problem long recognized by the orthotic industry. Compromises in support are being made with this foot type daily. It is important to realize that they are compromises, and suboptimal support is achieved. Suboptimal support can lead to poor symptom response, and even the creation of bunions, etc. Even in patients with 2 or 3 degrees of forefoot varus, I will try to modify the correction to place more support proximally with the Inverted Technique or the Kirby Skive. This way the anti-pronation support is not compromised, and the possibly damaging problems associated with full forefoot varus correction are eliminated.

Top 100 Biomechanical Guidelines #40: Root Balancing possibly damaging with Everted Negative Cast (Forefoot Varus type)

These are Forefoot Varus/Supinatus casts which stand in an Everted Position. When you use Root Balancing Techniques to fully correct, you may produce pathological (harmful) blocking of normal first ray plantarflexion with SAGITTAL PLANE BLOCKADE. You may also produce long axis of the midtarsal joint supination (at a time with the midtarsal joints should be fully pronated for stability). So, whereas Forefoot Valgus support with Root Balancing is sacred territory to fully correct, Forefoot Varus support with Root Balancing is filled with land mines and booby traps. More to come.

Top 100 Biomechanical Guidelines #39: Root Balancing Crucial with Inverted Negative Cast (forefoot valgus/plantar flexed first ray deformities)

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     When I am dealing with patients with lateral foot and metatarsal problems, I love when I find forefoot valgus tilts in their biomechanics. The correction for this everted forefoot tilt allows for Maximum Lateral Column and Metatarsal Support at the same time. The cast of the right foot below shows the negative cast capturing this everted forefoot to rearfoot relationship. When the forefoot has an everted deformity, the negative cast will sit inverted.

Here the casts are brought back to a more stable heel vertical position in preparation for making the postive cast corrections, and eventually, the orthotic devices themselves.

After this cast is filled with solid plaster, it will be leveled to the stable heel vertical position.

See how the lateral arch demonstrated here is just as high as some medial arch supports giving great lateral column support.

See how this lateral arch support will translate into great overall metatarsal support.

Here a little taste of how the process goes at the lab. Once the heel inverted position is noted, a nail is used to bring the cast back to a heel vertical stable position.

 Then plaster is used to make what is called a platform with the end point where the orthotic device (plastic) will end just behind the weigth bearing surface.

 Hopefully, this representation of the foot after the platform is in place shows the potential of great metatarsal support.

 Here the positive cast is placed down with lateral arch in full view. This translates into a great lateral or outside arch.

Here is an orthotic device made off a similiar mold with a inside and outside arch so similiar that it is hard to tell what side is the normal arch. Also, easily demonstrated, is how much natural metatarsal arch is created.

So, here is the magnificence of a Root Balanced Orthotic Device. In the next posts, I will be discussing the pros and cons of the Root Balancing of forefoot varus or supinatus. But, for now, I will finish saying balancing Forefoot everted deformities is the true greatness of the Root Technique. What are some of the problems treated successfully with this technique? These include:

1. Morton's Neuromas
2. Metatarsalgia
3. Tailor's Bunions
4. Bunions
5. Metatarsal Stress Fractures
6. Sesamoiditis/Sesamoid Fractures
7. Cuboid Syndrome
8. Midfoot Sprain/Arthralgias
9. Peroneal Strains
10. Ankle Sprains

Top 100 Biomechanical Guidelines #38: Evaluate Negative Casts for Inverted or Everted Forefoot Deformities

     The negative impression cast of the foot is the foundation of all Root-based Biomechanic/Orthotic treatment. It is an extremely important technique that the biomechanics industry is trying to replace with laser impressions, foam box impressions, and other variations of arch supports. Now that we are entering the age of CAD-CAM systems of manufacturing, it is up to the biomechanics industry to do the appropriate studies to decide when another technique will treat the problem as well as the classic Root Balance techniques based on the impression cast. For the appropriate patient, the power of the impression cast vs other techniques can be equivalent to treating a 1 inch short leg with a 1/4 inch heel lift. In the right direction, yes, helpful at resolving the abnormal forces producing symptoms, maybe not. From the patient standpoint, a significant dilemma exists. Are my symptoms not improving because I am in the wrong orthotic device, or because I need surgery, etc? For many years, the Root Device has been a tried and true method used by thousands of podiatrists/some physical therapists/some chiropractors/some orthopedists on millions of happy patients. When patients came into my office with orthotic devices 10 years ago, 90% of those orthotic devices were stable and reducing symptoms. Presently that number is diminishing. Patients need to expect more out of the orthotic devices if they do not feel stable, and they are not helping symptoms. Technology is a strong force to influence, but let us try.

     This Guideline #38 deals with understanding what they negative impression cast shows us. Below is the impression cast for a patient with forefoot valgus. This is the type of foot that the Root Balancing Technique shines and has no equal. If you have foot and ankle symptoms, and you have this type of foot, you should have a pair of these orthotic devices made.

The photo below is of a patient (Carina) with the forefoot valgus foot type where the first metatarsal is lower than the fifth metatarsal on observation. You can see if the cast captures this deformity by laying it on a flat surface. The cast will lean to the outside if the deformity is captured like the photo above.

Forefoot Varus is the opposite tilt seen where the first metatarsal is above the 5th metatarsal in this evaluation. The casts for a forefoot varus will lean inward like below.

.

These casts only represent the relationship of the front of the foot to the back of the foot. They do not represent the foot to ground relationship ( a common misconception). I will have so much more on this concept. For biomechanics experts, I am intentionally not separating forefoot valgus from forefoot pronatus, plantar flexed first rays, and dorsiflexed lateral columns including dorsiflexed fifth metatarsals, for ease of this discussion.

In conclusion, I love when I find a forefoot valgus to support when I am dealing with many, if not most, foot and ankle problems. Forefoot valgus occurs in 40 to 60% of all patients. More on the more complex forefoot varus later.

Top 100 Biomechanical Guidelines #37: Major Stability can be Attained with Full Root Balancing of Forefoot Deformities

Taken from Root Lab brochure. Dr Mert Root, my teacher, my mentor, my friend. I miss you. Passed away after a long illness in 2002.
http://www.root-lab.com/about.htm

Dr Mert Root, along with several other brilliant doctors (Weed, Orien, Sgarlato), revolutionized the treatment of foot problems with their theories in the 1960s and 1970s. A Balanced Root Orthotic Device is the standard that all orthotic devices are modifications. To design a balanced orthotic device, you are eliminating the intrinsic tilts in the foot, the forefoot varus, forefoot supinatus, forefoot valgus, forefoot pronatus, plantar flexed first rays, plantar flexed fifth rays, etc, etc. Being a purist, Dr Root preached full correction of these corrections. Disciples followed that espoused modifications for comfort, sometimes they were right and sometimes they ruined the technique. Most labs will make the classic Root Balanced Orthotic Device if asked, but their standard is their version of a  Modified Root Balanced Orthotic Device (normally function loses to comfort). But, the debate will rage for decades whether the purest 100% correction of these natural tilts in the foot is that important, or whether 80% correction is okay. Or 70%. Or 60%. I believe it is important when using the Modified Root Balanced Orthotic Device to clearly document what type of correction you are using. If the symptoms are not improving, further correction towards the classic Root Balanced Technique can be ordered. I know this works, and will dedicate a few posts to this topic. I use so many types of orthotic devices, but the Root Balanced Orthotic Device is the best for many conditions. These include:

1. Morton's Neuromas
2. Hammertoes
3. Midfoot Sprains
4. Metatarsal Fractures (including Jones type)
5. Metatarsalgia
6. Tailor's Bunions
7. Pes Cavus Problems

I hopefully will be able to introduce you to Root Balancing. I owe it to Dr Root, an unbelievable giver, and healer. His son Jeff, and daughter in law Kathy, run his lab still, even though Dr Root passed away in 2002. A terrible loss.

These are forefoot varus impression casts of the foot. When you stand them up, they lean inward. A Root Balanced Orthotic Device will attempt to place these heels straight up (heel vertical)

These are forefoot valgus impression casts. When you stand them up, they lean to the outside. A Root Balanced Orthotic Device will attempt to stand them straight up (heel vertical).

This is simply an introduction to a hot topic in podiatry. As more and more labs go computerized, and the health care provider has less and less control of the final product, the consumer may have to be more demanding. I have made a good living converting modified Root Balanced Orthotic Devices to classic Root Balanced Orthotic Devices to achieve better stability and better symptom relief. Talk to your podiatrist whether they use classic Root or modified Root techniques. Root technique is like the paint brush however, the individual provider must have the freedom to paint.

Top 100 Biomechanical Guidelines #36: Root Balancing Key to Correct Forefoot Abnormalities

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 Podiatrists, and many physical therapists, make orthotic devices and other biomechanical decisions based on balancing the patient's forefoot abnormalities. When the primary function of the orthotic device is to support structural problems in the foot, the orthotic devices is called a balanced orthotic device or Root balanced orthotic device. Dr Mert Root, the founder of modern day orthotic devices, first published and lectured extensively on this subject in the 1960s and 1970s. It is still to many health care providers the only way to treat patients. The next few weeks I will be discussing the biomechanical guidelines surrounding this type of approach.

     It was the 1980s that the next explosion in biomechanics occurred with the development of Corrective orthotic devices with Biaxial sectioning, Inverted technique (my invention), Kirby Skive, and other modifications. Here the foot was modified to correct the forces of pronation more than could be accomplished by Root balancing or modified Root balancing. Here will be many posts on these sections.

Ah Chihuly!!

 This is the typical appearence of the outside or lateral arch in a Root Balanced orthotic device. The foot is suspended off the ground along the lateral side of the foot. This is crucial in supporting feet with many injuries including metatarsal fractures, neuromas, ankle sprains with instablility, etc.

Now see the mold below. The lateral arch is filled in. This is more like an OTC orthotic device now and loses its effectiveness for many injuries. 

Below is the orthotic device designed around Root Balancing. See the great lateral and medial archs. With this type of orthotic device, there are times when you can not tell which is the inside arch and which is the outside arch. Root balancing is classic podiatry and since it can be more harder to get used to, it is commonly lowered labs whom want to make a comfort orthotic device. Unfortunately, the effectiveness of the orthotic device may be greatly sacrificed. This the the common look of an orthotic device for a forefoot abnormality called forefoot valgus or plantarflexed first ray.

        

Top 100 Biomechanical Guidelines #35: Use Common Shock Absorption Modifications Routinely

Patients, with or without orthotic devices, should never feel that they do not have hope at a soft comfortable impact against the ground. There are so many products out there for dampening shock, and these products are used in many imaginative ways. Here 3 commonly utilized products for shock absorption are demonstated: gel, spenco, and plastazote. They definitely should be part of every shoe/orthotic program, at least in some form or another. I am showing here how I commonly use these 3 products, but there are many acceptable variations. The goal is that the patient feels supportive, but cushioned. Too much cushion however can make a patient more unstable, so there must be a good balance between cushion and stability.

Plastazote Foam Material - 1/8'' x 6'' x 1 yd. (3.2m x 15cm x 91cm), 1 Roll

One of the most important aspects of designing a good orthotic device is shock absorption. Here adhesive back gel sheets are attached to the heel area of orthotics to help with shock absorption while utilizing a plastic orthotic device for maximal stability. Normally 1/8inch gel is utilized, but up to 1/4inch can be used.

http://www.silipos.com/003_prod/product.aspx?cat_name=Orthopedics&subcat_name=Gel%20Pads%20&%20Sheeting&product_name=Gel%20Squares&product_id=155x5&cat_id=7&subcat_id=7

Spenco is the best shock absorption material as an insert or orthotic cover. Here, a knockoff spenco, is being used. The original Spenco is still the best and is always in green.

http://www.spenco.com/products/footcare/SpencoRX/product-productcomfort-insoles

Pink, or #1, plastazote is the memory foam used as the top layer in a Hannaford custom made orthotic device. Here it used as a forefoot extension on an orthotic device in 1/4". I commonly use 1/8" as a full length top cover on an orthotic device.

http://store.acor.com/products/Plastazote%C2%AE-Polyethylene-Foam-%252d-RETAIL.html

Top 100 Biomechanical Guidelines #34: Understand the Basic Components of a Hannaford Orthotic Device

     This is my last post for awhile on the Hannaford Orthotic Device. It definitely changed my practice of podiatry, and the patients it has helped are forever grateful for them. I have tried to put all of the steps in their manufacturing down, so any laboratory around the world can make them. If you are in need of orthotic devices to help with shock absorption at your feet, shins, knees, hips, or low back, consider this orthotic device. It is the best product for this purpose I have ever seen.

Hannaford Orthotic Device before ground into proper shoe fitting size designed off a cast of the foot.

What are the Basic Components (in summary)?

• 1/2" flesh/pink soft plastazote (also called plastazote #1) full length acts like memory foam--never touch that layer with adjustments as it molds to the individual foot.

http://www.alimed.com/Alimed/product/Plastazote-1-Sheets,15063,169.htm

• 1/2" white medium plastazote (also called plastazote #2) sulcus length gives durability.
• After 30 hours of wear the initial compression has taken place, and the shoe fit is better.
• Barring any problems, the ortho is refurbished in 3 months.
• If the patient loves the orthotic device (and most do), they are encouraged to get a second pair around 6 months, for ease of refurbishing, and for alternating to save the life of the orthotics.

Top 100 Biomechanical Guidelines #33: Hannaford Orthotics should be Refurbished every 3 to 6 months

I love to cover Hannaford Orthotic Devices with leather initially to see the wear patterns, especially correlating the wear patterns to what I see in gait, and comparing right to the left sides. The wear patterns may reveal that the foot needs more padding in certain areas, or where there is more need for pronation or supination support.

With the Hannaford Orthotic Device, 30% of the bulk is reduced over the first month as the memory foam molds to the foot. Around 3 or 4 months into wearing the devices, medial and lateral buttresses are applied to the bottom to improve the pronation/supination stability dramatically. I use 1/8 inch grinding rubber for this purpose. (see the post on grinding lifts for ordering of this material).

I also change the thinner leather with thicker 1/8 neolon/spenco for better shock absorption while refurbishing.

Normally, when using the Hannaford device, a new one is ordered at 3 to 6 months. In this way, the patient can have adjustments made on both pairs at any office visit, and can alternate between the two pairs which saves the life of each pair dramatically. By alternating, when one pair begins to be less supportive, or more painful, or both, compared to the other pair, you will know when it is time to have it refurbished.

Top 100 Biomechanical Guidelines #32: Stress Fractures and Joint Arthralgia treated with Increase Shock Absorption

     Shock Absorption is needed following the impact (collision) of the foot against the ground. The shock wave that radiates up the leg is approximately equal to your body weight with normal walking, increases as you increase speed or go downhill, and can measure 2 to 5 times body weight with normal running. It is this shock wave that needs to be reduced to help many avoid injury by changes in shoegear, changes in surface, changes in shoe inserts, and custom made shoe devices. The King of all is the Hannaford Device. Hundreds of my patients have benefitted over the last 25 years, and I am hopeful to spread the word on how it is made.

     Hannaford Orthotic Devices, developed by Dr David Hannaford while practicing podiatry in Eugene, Oregon, are 2 layers of 1/2" plastazote material vacuum pressed around a mold, and then ground into shape to fit a typical athletic shoe. The layer of plastazote material against the skin is memory foam, soft in nature. The second layer of material is white plastazote, firmer and more durable in nature.

Impression Casts are used to make a Hannaford Device.

The 2 sheets of plastazote are cut with the memory foam full length and the white, more durable, plastazote cut to sulcus length (just behind the toes).

The length of the soft plastazote is approximately 1 and 1/2" longer than the foot and will be trimmed after the molding to fit better.

This is how the 2 pieces will be pressed with the softer memory foam against the foot.

Before vacuum pressing, both pieces are glued with Barge Cement so they will become like one after the press.

Before pressing, the toe area of the mold is covered with a soft material to flatten this part of the press. Without this, the memory foam molds around the toes too much. You need the orthotic to end up longer than the original foot.

The 2 pieces are placed in the convention oven heated at 475 deg F. Because the white layer heats up slower than the pink layer, the white layer is placed down on the surface.

Within the convention oven, the plastazote material is checked every 20 seconds and removed when the toe area begins to brown. A spatula is used to remove, but it can be handled gently with your hands.

Here it is centered over the mold with overlap around both sides and front and heel. You need to get as far forward in the press as possible for the best press. See the memory foam layer is being placed against the foot.

Once the press is started, you need to push down from the sides to help the vacuum remove all the air. The press is normally done in 20 minutes/foot.

After the press, wrap the mold with plastic wrap tightly for 1 hour to let the material cool completely in the shape of the mold.

Once removed from the wrap, mark the front length approximately 1 and 1/2" from the end of the mold, and mark the sides the exact width of the foot. Since I have a video of the grind, I will let that finish this post off.