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Sunday, December 27, 2020

A Typical Orthotic Manufacturing Day

As many of you know, I make my own orthotic devices. Occasionally, like today, I have fallen behind and I need to finish around 5-6 pairs all at once. Typically, my goal is one per day, and I can do that during a day I see patients. But, today is Sunday, after my glorious week off for Christmas, so here I go. 
My brother Robert Blake, or just Uncle Bob to my children and grandchild, works Friday and Saturday for me completing 70% of the orthotic process. I have to prepare the work load on Thursday and Friday nights, I also personally review the positive cast he has prepared, and make modification as are necessary, so I am always happy with the correction for the patient before pressing the plastic. 

Orthotic Device #1

This is your typical dress orthotic device. There are no rear posting and it is made narrower than an athletic pair. When you narrow an orthotic device, since the lateral or outside border of the foot should be a perfect match for cuboid stability, you always narrow from the medial side. 

Here I have added 1/8th inch Poron to the top of this orthotic device. Poron is one of the best shock absorbing materials (which will be helpful for this patient with hip arthritis). Poron however is fragile and has to be covered by something so I am using a thin soft piece of leather. 

Orthotic #2 through #6 The Hannafords
The initial grind is making a heel cup 

Today I will be making 5 pairs of Hannafords. Two of them for a patient with chronic metatarsalgia and the full length nature of the device is wonderful and soft. The memory foam gradually creates a perfect impression of the foot. 

Typically I make my Hannafords 2 inches longer than the foot and then trim to the shoe insert at the time of orthotic dispense. 

After the heel height is made, the width is taken in removing all but 2 mm thickness in the heel area only

2 Pairs of Hannafords shown here with the heel cups made and the thickness of the heel cup about 2 mm all the way around from medial to lateral

After grinding the heel cup, the medial and lateral borders must be straightened so it will fit in a shoe. All the excess from the heel to the toes must be removed medial and lateral. 
Bottom view of all the side excess gone

Top view of all the side excess removed

And now for the bottom grind. The bottom is ground flat and parallel with the front surface. Any varus or valgus tilts needed for a patient’s biomechanics is applied later. The Hannaford, which can be made off any representative mold that you trust, does not balance forefoot to rearfoot deformities (like plastic based orthotic devices can). 
The bottom grind starts at the junction between the firmer and more durable white plastazote layer and the softer (against the skin) orange plastazote layer. It is important that this transition is smooth and the white layer all the way back to the heel is parallel to the orange. 

The flat base grind shows a contact point exposed of orange material at the heel. When the initial press is made, 1/2 inch of full length orange plastazote is glued to 1/2 inch sulcus length firmer white plastazote, heated only for about one minute in 450 degree oven before vacuum pressed. The longer you heat, the more the plastazote will compress in the vacuum press thus becoming thinner. 
Here I am attempting to show a flat base from heel to toe after my grind. 
Here is just a reminder that I am doing each step to 5 pairs of Hannafords at the same time. 

The outline is the material on the bottom of the orthotic device that did not get ground flat. The part around the heel is removed by blending into the heel cup. The part in the arch is ground smooth to make a distinct arch. 
Here the heel area now has 2 distinct parts: flat bottom surface and heel cup walls.
Now the front (tip of the toe area) is tapered down, compared to a non-tapered Hannaford which would crowd the toes too much
The front is smoothed flat and the transition from front to arch area smoothed
Here you can compare the smoothed top (probably needs alittle more work) versus one that has not been touched at all on the top surface. 
Smoothed Transition into the arch

Non smoothed transition
Smoothed medial arch

Medial arch before smoothing
Example lateral arch before smoothing

Lateral arch with some smoothing
It is important to note that memory foam orthotic devices like Hannafords get their stability from the walls of the shoes that they are placed in to a big degree. I never touch the top surface of a finished Hannaford, other than forced to use a metatarsal pad occasionally, since I want the top layer to become a perfect fit to the patient after about 30 hours. The bottom layer however can be modified as much as seems fit. 
And yes, I did finish 5 today!! This is a nice 1/16 inch neolon top cover.  When the orthotic compresses, I replace this at the month follow up visit with 1/8 inch Spenco. 

Some of my patients gave me the shoe insert so I could fine tune the sizing before they come in. Smarter than me!!

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Thank you very much for leaving a comment. Due to my time restraints, some comments may not be answered.I will answer questions that I feel will help the community as a whole.. I can only answer medical questions in a general form. No specific answers can be given. Please consult a podiatrist, therapist, orthopedist, or sports medicine physician in your area for specific questions.