Clinical Biomechanics for Podiatry (Post # 1): Orthotic Designs: Positive Casts before Balancing

In designing orthotic devices, to achieve positive functional changes, and positive symptom outcomes, the prescribing health care provider needs to be fluent in orthotic casting, orthotic prescription variables, etc. I took 20 casts of my wife Pat's left foot to show common variables in orthotic prescription writing. The first cast I poured with plaster and left it uncorrected (the yellow positive cast below). The other 19 casts of her left foot I corrected various ways to achieve various functional results. I will try to show you that even though a good cast is taken (podiatry's Gold Standard in Root Biomechanics), your goals of what you are trying to achieve functionally and symptomatically may require a wide range of orthotic variables.

These 3 positive casts were made for 3 different patients: Orange for high degree of Forefoot Varus, Pink for high degree of Forefoot Valgus, and Yellow (my wife Pat) for a Neutral to Slight Varus forefoot to rearfoot relationship. 

Here are these 3 feet seen from the back of the heel. These represent the negative cast which were taken of three left feet. The Orange cast of a high Forefoot Varus deformity shows the heel collapsing into valgus to get the front of the foot to the ground. The Pink cast of a high Forefoot Valgus foot type shows the heel falls into varus to bring the forefoot to the ground. The Yellow cast (my wife) represents the more Neutral Forefoot to Rearfoot showing the heel position more near a vertical position. The orange and pink foot types are simple to analyze and correct and untreated can lead to devastating foot compensations and pain syndromes. 

Here is a blow up photo of two left feet positive casts. The one on the left shows FF Varus where the forefoot is inverted on the rearfoot. 20 to 50% of patients have this problem. After the foot lands on the ground, to get the big toe to the ground, the arch must collapse and the heel roll into valgus causing severe over pronation. The cast on the right (pink) shows a left foot of FF Valgus. This foot type must roll the heel out to get the metatarsal weight evenly spread and the foot stable. However, this outward roll of the heel, also called over supination, under pronation, or lateral instability, causes a very unstable foot. Try standing on the outside edge of your foot and see how stable you feel. The goal of orthotic devices with these 2 foot types is to get the feet balanced, centered, with the heel straight up and down. This is the goal for what is called Root Balance Technique. 

The Yellow cast of my wife's left foot shows a very Neutral foot. It is very stable. All the negative casts are poured with the heel vertical by propping up one side or the other to get the vertical heel position marked on the cast to be perpendicular to the top of the foot. This is the Gold Standard of Root Balanced Orthotic Devices, but can be your reference in other cast corrections such as the Inverted Orthotic Technique. 

This is a soft based orthotic device made directly off the uncorrected positive cast. By uncorrected, I mean no attempt was made to change the position of the foot. I will demonstrate in some of the upcoming posts, how simple changes to the positive cast correction can make powerful changes in the foot position. This soft based orthotic device is called an Accommodative Device and more correctly called a Hannaford Device (as first invented by Dr. David Hannaford).

Tuesday's Question of the Week: Multiple Pain Syndromes: Email Advice

Dear Dr. Blake, 

I have been following your blog for two years now.  I credit your blog for keeping me walking. The tips and advice I have read have helped me along this far.

I am a 41 year old very healthy female.  Until November of 2009 I was a runner, recreational athlete, and yoga instructor.  I woke up one day in November and noticed my knees were aching.  I had replaced running with using an elliptical trainer due to separating my shoulder 9 months earlier.  I thought maybe the elliptical was causing an imbalance, so I beefed up my hip strengthening at the gym.  My knees continued to hurt.  I saw an orthopaedic surgeon. I had an  Mri of both knees ( 3 times), went to physical therapy.  Physical therapy made things worse.  I developed quad tendonitis.  I could not bend my knees.  Sitting with bent knees was excruciating .  My knees burned and would get very hot and red.  I found a new doctor.  Then another doctor and a chiropractor.  Had RA labs drawn ( 3 times) .  All negative.  Found a biomechanics expert.  Started working with him exclusively. I made a little bit of progress. 

Two years later my left foot started to hurt and my entire lower leg. Then both feet and lower legs started to hurt.  Peroneals, post tib, calves, the ball of my foot. I could no longer stand barefoot ever. I wear shoes in the shower. I started going to podiatrists after ten days of unexplained pain.  I went to five different doctors in my area.  All found nothing.  All insisted I did not need orthotics. One went so far as to say he wished he had my feet. He said he thought I had fibro. He said orthotics are golden arches and to not to come back unless I broke my foot.   I had previously visited a physiatrist at University of Florida who ruled out Fibromyalgia. 

Dr Blake's comment: If you have pain in your foot, some form of orthotic device can help. There is a infinite range of devices to work with and all the variations of support and cushion and off weight bearing. 

I found your blog.  You advised a reader to look into Barry University.  I found a doctor a few hours from where I live.  The minute they looked at my feet I knew something was wrong.  They could not believe the atrophy of the balls of my feet for my age. They recommended orthotics.  Another option was sculptra injections in the balls of my feet.  My first pair of orthotics were made of hard plastic and the heel cup was too small.  I walked around on those orthotics for 3 months, then my heel fat pads started to thin, but my knees started to get better!   Orthotics were sent back and I was referred to another doctor to start sculptra injections.  New doctor made softer orthotics and injected sculptra.  The sculptra helps a lot.  It did take about 18months and several rounds to get to this level of comfort.  Sculptra is very expensive and does not last more than 6-7 months. The balls of my feet still get hot every night and sore.  I still have to where soft orthotics and soft tennis shoes.  I no longer hard limp all day which is a miracle. My knees no loner hurt every day.  Just every now and then. 

Dr Blake's comment: I am so proud of you for not giving up. If your doctor can send me a cast of your foot, I will make a Hannaford for you. But, I need a doctor/pedorthist to dispense/adjust. Hannafords would be the best design for your feet. 

http://www.manhattanfootcare.com/2013/03/sculptra-derma-fillers-for-treatment-of-foot-conditions/

http://www.drblakeshealingsole.com/2010/12/top-100-biomechanical-guidelines-31.html

My heel pads have started to thin again. I can feel the bones easily when I palpate my heels.  It hurts along the outer rim and along the back of heels.  It feels like I always have a blister when I do not have one. Hurts a lot.  Gets red and hot every night.  I use ice packs a few times a day, every day. I have to sleep with my heels off of the bed, because the pressure hurts.

Dr Blake's comment: Here is the links to two products you should buy.

https://www.mooremedical.com/index.cfm?/Achilles-Heel-Pad%E2%84%A2/&PG=CTL&CS=HOM&FN=ProductDetail&PID=166&spx=1

http://www.alimed.com/stay-on-heel-protector.html

 The orthotics I am wearing are slow recovery poron with spenco on top.  This worked for about a year. I have currently stuck a thin gel sheet over the heel portion.  Not perfect but helps. Thinking of buying J gel.  In October the spenco was replaced but not the slow recovery poron.  Spenco bottomed out in a few weeks.  Heels hurt.  the physician I currently see always keeps my orthotics for 4-6 months before I get them back. I never leave my current pair .  The adjustments have to be made when I am in the office.  I have been waiting for my new pair since October.  When they do come back the lab has usually botched them.  I have become my own pedorthist.    I have a dremel tool.  I make my own met pads . I add cushioning to my orthotics.  I wear my orthotics at all times,  except in the shower. 

Dr Blake's comment: Sounds like you deserve at least a honorary Podiatry degree. This is why I make my own orthotics. If only my patients really understood my dedication. Partially LOL!!!

I  need orthotics that will help my very boney feet to stop hurting so much.  I think that the right orthotics will keep my feet protected and comfortable and keep my knees happy.I worry that if my feet are this bad now, what will happen in the future?  I can come to California if needed to see you.  My exercise physiologist said I have 20 year old bones and 80 year old fat pads.  It would be wonderful to  get my life back.   So many doctors have turned me away.  I want to know if you believe you can help me? 

Thank you, 

Dr Blake's comment: I have since communicated with the patient and sending her a size 10 (her size) Hannaford. The wonderful part of a Hannaford is what you get back from the lab is just a little more than an insert with your foot length and width. The Hannaford is multi layers of memory foam and you do the molding during your first 30 hours of wear. They feel like walking on a cloud, but need big enough athletic shoes to fit them. If you are looking into Hannafords, I am happy to work with doctors and labs to learn how to make them. Read all the posts previously on Hannaford orthotic devices. 

http://www.drblakeshealingsole.com/2013/01/grinding-hannaford-orthotic-you-tube.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.

Hannaford Orthotic Device: New Balance 623 a Great Shoe

As you can see from previous articles that the Hannaford Orthotic (the best for shock absorption) can be very bulky. Recently, one of my patients Bob, went on a big search and found the New Balance 623 (comes M and W) worked the best. It is a cross trainor type. The variable widths help this immensely. If other patients have found shoes that work well, please email or comment on this post.

Hannafords before they have been grinded into better shoe fitting shape.

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.

Top 100 Biomechanical Guidelines #31: Hannaford Orthotic Devices best for Shock Absorption Issues

Dr David Hannaford from San Rafael California revolutionized the orthotic world for patients with shock absorption problems. These are patients with knee arthritis/pain, hip arthritis/pain, stress fractures, heel bruising, and shin splints. Check out my YouTube video on the grinding process.



You can also see the general discussion of addressing shock absorption issues on this YouTube video.




Any podiatrist, orthotic lab, or pedorthist interested in learning the nuances of manufacturing this device I will be happy to share the steps. Please email me. I will have a full post soon on the entire process.  It is a great device for many patients.

A Hannaford Device is typically full length and made off a cast of the foot. The top layer of soft plastazote material is a memory foam which molds to the patient's foot. A leather top cover is used since it shows all the stress points and can help in discovering the best modifications if necessary.

Foot Orthotic Devices: Hannaford best for Shock Absorption

     I would like to introduce you all to the Hannaford Orthotic Device. Dr David Hannaford from San Rafael California introduced it into the profession of podiatry in the 1980s after years of treating athletes. For this, I owe Dr Hannaford a long overdue Thank you!!! It is the best orthotic device on the market for many conditions needing cushion and support. The top layer is memory foam, and the subsequent layers give some structure and durability. If you have chronic heel pain, chronic stress factors, chronic knee or hip joint pain, and wear shoes that can accommodate a bulky orthotic device, this is the orthotic device to try.

     It is a product unfortunately not made by any orthotic labs, but can be easily learned. I make them for my patients, and for the doctors in our clinic patients. There is a slight learning curve when using them, but their use must be increased. I will try to expand it's use through this blog. I will try to encourage my patients with this device to comment on the device and what it has done for them. Any mold impression of the foot can be used to manufacture this device. As the memory form compresses for the first 30 hours of wear, the device actually gets alot better. The photo below does no justice to its effectiveness. It is a temporary orthotic device lasting one year, but many patients choose it as their permanent orthosis with yearly remakes.

The material used is 1/2" plastazote with the soft orange against the skin and the more supportive on the ground. The 2 layers are glued together before pressing.

A vacuum press is used to press around a mold of the foot under high pressure and allowed to cool in shape.

The material is removed from the mold and excess material cut off with scissors before the grinding process begins.

The grinding process takes a little time to learn, but any lab or doctor could learn the 10 plus steps fairly easily if they want to learn.

After the grinding is complete, a leather topcover is applied after gluing both surfaces. The leather allows the clinician to check the wear pattern on follow up visits.

I sure hope if you need a Hannaford Orthotic Device for maximal shock absorption for chronic stress fractures, chronic heel pain, knee or hip arthritis, this post will allow you to get the device easier. I have seen hundreds of types of orthotic devices, and never seen a device that works so well when maximal shock absorption is needed.