Orthotic Modifications for High Arched Feet (Pes Cavus)

Special Topic: Orthotic Modifications for Over Supinated Feet

In most cases I am not designing a foot to correct a “foot type” but to provide a solution for a specific clinical problem. While having a high arched, over supinated, under pronated foot may predispose to certain problems other “foot types” can have many of the same problems.

Some problems that can occur and are related to supination movements (or even “moments”) include:

  •  chronic and repeated ankle sprains
  •  peroneus brevis tendinopathy
  •  peroneus longus tendinopathy
  •  cuboid stress fractures
  • 4th and 5th metatarsal stress fractures
  • 5th metatarsal base or midshaft fractures
  • lateral leg pain (peroneal muscle group)

In many instances with problems like these, immobilization may be necessary for a time. Wobble board training should be incorporated into rehabilitative programs. The purpose of the wobble board training is to have the neuromuscular system adapt the peroneal muscles to performing repetitive firing for stabilization. The angles that the wobble board makes with the ground and the motion and angular relationships that it engenders in your ankle and leg are ideal to training the peroneals to fire appropriately.

The wobble board assists in training muscle strength, balance, and improving joint position sense. There is nothing that beats this 3 in 1 training.

For patients who do not have a dramatic Pes Cavus foot there are a few specific corrections I include in the orthotic:

  • Accurate cast of the foot.
    I do not want a 2D pressure scan. I want to hold the foot in neutral subtalar joint position. And I want to plantar flex the first ray by either light dorsal pressure over the first metatarsal or by slight dorsiflexion of the great toe during the casting.
  • Minimal cast correction.
    I want the cast to reflect the shape of the foot to mirror it so that when I want to alter forces, they will be altered by the shape and adjustments to the orthotic. I want the forces distributed through a large surface area and need conformity between the shape of the foot and the shape of the orthotic.
  • No lateral bevel.no-bevel-post
    This resists over supination directly. It is like an outrigger on a boat. It also changes moments of force going into the foot.
  • 3 degree lateral forefoot wedge.
    This is often used to prevent over supination of the foot after the heel as left the ground or as weight is transferred towards the forefoot.

These are often my starting steps to deal with the problems listed above when they are resistent to treatment.

For a Pes Cavus, high arched, over supinated foot podiatrist Richard Blake, DPM has put a great video on line. It details his 8 steps to deal with this foot type using specially customized orthotics. The modifications made for this problem are not found in over the counter orthotics. And many specialists do not see enough patients with high arches to be adept at treating the problems associated with this foot type. It is important to find a physician that has experience with sports medicine, high arch feet, and biomechanics.
The Blake 8 Steps (only slightly modified) follow:

First an accurate cast is required as described above.

A) Rounding of the lateral border of the cast or via CAD/CAM to have the orthotic better grip the foot.
B) Lateral Kirby Skive. Often 2 to 4 mm.
C) Deep Heel Cup – up to 25 mm.
D) Extended lateral heel cup or “lateral flange”
E) Eliminate “medial heel grind off” and/or add No Lateral Bevel in rearfoot posting instructions.
F) Lateral arch fill to add more surface contact area
G) Narrower orthotic (sometimes) to limit any antipronatory forces. (note: some will go for wide or nomal width for increased stability and contact)
H) Forefoot modifications such as lateral wedgehttp://www.prolaborthotics.com/Products/PathologySpecificOrthoses/LateralAnkleInstability/tabid/138/Default.aspx

Dr. Blake reviews these modifications in a 9 minute video on YouTube: https://www.youtube.com/watch?v=hMhrTmWXfDA

This video is well worth watching for anyone who needs the modifications or anyone who is planning to incorporate them into a patient’s orthotics.

Note: Images Courtesy of ProLab Orthotics

High Arches can make you feel like you are heading for your own personal apocalypse. Turn it down and listen to Arch Enemy with some heavy metal:

Or if you feel like stepping out, you can go retro with John Mayall’s Bluesbreakers:

Jacquelin Perry, MD (1918-2013) – Pioneer of Gait, Biomechanics and the Treatment of Neurological Disorders

Dr. Jacquelin Perry (1959)Jacquelin Perry, M.D. has just passed away at age 94. She was born on May 31, 1918 and died on March 11, 2013.

Dr. Perry was a key researcher in gait and abnormal gait. She was a pioneer as one of the few female orthopedists in the 1950’s becoming board certified in 1958. It is hard to imagine today, but there were only 10% women in her medical school class, 7 out of 76.  She taught at USC Medical School from 1972 until the late 90’s. She worked at Rancho Los Amigos Medical Center in California for many years and was Chief of Pathokinesiology and later Chief of the Biomechanics and Gait Lab among other positions. More recently the Jacquelin Perry Musculoskeletal Biomechanics Laboratory was dedicated in December, 2008

She is best known for her work on polio patients and her 1992 text Gait Analysis: Normal and Pathological Function” became an instant classic. The Salk vaccine, introduced in the mid-1950’s, effectively ended polio in the Western World fairly quickly. Dr. Perry directed her attention to improving a rehabilitation program for spinal cord injury, work on hemiplegia, and children’s neuromuscular disorders including primary muscular dystrophy, myelodysplasia, and cerebral palsy.

Before beginning her medical studies Dr. Perry studied physical therapy and served as a physical therapist in army hospitals during WWII from 1941-1945. She reported that in addition to trauma patients, she had been exposed to polio patients during this time which spurred her interest.

From an early time in her career she began observational gait analysis and worked to codify her observations. Later video and EMG (electromyography) and forceplate observations were added.

Her clinical observations and descriptions of “loading response” were clear and had implications for many biomechanists. She also well described the terminology which led to an emphasis by some on “sagittal plane biomechanics”:

  • Heel RockerRock and Roll - Jacquelin Perry
  • Ankle Rocker
  • and Forefoot Rocker

She is acknowledged often in the physical therapy community. Dr. Perry has inspired many to research in gait and biomechanics. But all biomechanists know of her work and realize the thanks owed to her for her interests, work, inspiration and research. We often have had a more limited acknowledgment of our forebearers but she is certainly a major one in the realm of biomechanics and gait analysis.

While we now have improved measuring devices (in laboratories and sometimes in clinical offices) and we measure and make observations of moments of force in addition to the things we can see, her work has had tremendous impact and has had much value. As Galileo performed visual observation with his telescope long before we could study pulsars, quasars and black holes, Jacquelin Perry worked well with the instruments she had available. Eyes and a brain were among the instruments she often put to good use and was the starting point for much research and treatment. Her life is an inspiration to innovation, passion, dedication, persistence and endurance.

Heel Lifts and Achilles Tendonitis (Tendinopathy) (repost 2008)

Point / Counter Point: The Truth is Out There Somewhere (or maybe here)

Every now and then the “Fear Factor” comes to the Internet. And if you travel the running blogosphere, you’ll discover that sometimes it takes the form of a red alert for heel lifts for Achilles tendonitis. It seems that some would rather have you run in pain or give up because of the pain for fear that a 1/8″, 1/4″ or 3/8″ lift which alleviates the pain could cause a tendon to “pop”. There is evidence that the sound of a tendon popping may come after an indiscriminate intratendinous injection of steroid though. 

The truth is one should pay attention to what your body is telling you. Running in pain which causes an alteration in form is not good. It will most likely lead to both your original injury not improving, and a few additional injuries because of your altered gait.   

With the knowledge that medicine is an art and a science, it is probably best to avoid dogmatic opinions such as  “no, no ,no” to a heel lift. While some will be helped with shoe and surface corrections, orthotics, stretching and strengthening alone, the addition of a 1/8 – 3/8″ heel lift can often make the difference in both comfort and eventual healing of this condition. The lift is used on both sides to avoid creating a longer leg and altering the gait in such a manner that could create low back pain, hip pain or other problems in the absence of the affected leg being a short limb. The lift is best made of a non-compressible material. It is extremely important to avoid compressible materials which will lead to continued slow stretch movement which could add to either activating the stretch reflex of the achilles tendon or allow for eccentric contraction of the muscle-tendinous complex. This may work to inhibit the healing of the tendon, and stop the individual from being able to run without pain. We certainly, and the ladies among us, especially, will vary our heels by much more than this over the course of a week. A slight change in the heel contact and foot angle should not put your Achilles tendon at greater risk of injury. 

While there are flaws in evidence based medicine and in the ability of us to accurately predict those most likely to become injured, there is  no evidence that 1/8 to 3/8 ” lifts cause ruptured Achilles tendons. Not even the slightest hint that muscles and tendons would be ruined by such a lift or adapted so much that you’ll never be the same. I do not know of any study that shows a 1/4″ lift used for a limited amount of time each day could shorten the muscle/tendon complex. There is adequate time spent in other shoes, barefoot, and even doing stretching exercises. 

Running in pain without a heel lift, or more dramatically running on a soft surfacer with a mushy, over cushioned shoe or a racing flat is far more likely to lead to chronic pain and disability. Proper orthotics are a must, along with avoiding over cushioned running shoes to prevent the tendon while functioning from being over stretched and causing eccentric working of the muscle-tendon complex . There seems to be no reason to avoid a heel lift, but it is not the be all and end all of a program to treat Achilles tendonitis. 

For more details:

Website article: Dr. Pribut on Achilles Tendon Injuries

 Previous Blog entry on Achilles Tendon and stretching

Quick Search of Textbook Comments On Heel Lifts:

I wasn’t sure what I’d find in the texts, but thought it would be interesting to see what other minds have come up with on this issue. I did not think that Noakes would agree with the heel lift, but he did. I do not know what is the scientific basis or aggregate clinical experience to imply that heel lifts are the worst possible therapy for this problem. 

Alfredson, H. and Cook, J. in Clinical Sports Medicine, 3rd Edition eds. Bruckner et. al. McGraw Hill 2006, reprinted 2007. Chapter 32 “Pain in the Achilles Region” p.  606 “A heel lift worn inside both shoes (0.5 – 1.0 cm, .25-0.5 “) is a good practical way of unloading the region. 

Alfredson is famous for his self termed “painful” eccentric stretching for non-insertional Achilles tendinopathy. He has published numerous articles on Achilles tendon problems and on the treatment of them. I am not convinced that eccentric stretching is appropriate in as many cases it is recommended. If you find something isn’t working, including the eccentric work is not helping, you need to change the approach. Measurements have shown that the calf is often weak in eccentric strength when one has Achilles tendonitis. One approach is to work on strengthening that (which can be painful). The other is to diminish the pain by lessening stresses which add to the eccentric contraction strength required. Both approaches and sometimes a combination may be appropriate for different patients and at different times for a specific patient.  I continue  to read Alfredson’s  articles with interest. (And in actuality will recommend his exercises in a manner and when it can be done without causing pain. 2012)

Bradshaw, C. and Hislop, M. in Clinical Sports Medicine, 3rd Edition eds. Bruckner et. al. McGraw Hill 2006, reprinted 2007. Chapter 31 “Calf Pain” Since the calf includes the muscles which create the Achilles tendon, we’ll look at comments in this chapter also. “A heel raise should be used on the injured and uninjured side”. 

Title, C. and Schon, L. “Achilles tendon disorders including tendinosis and tears” in Baxter’s The Foot and Ankle In Sport, Second Edition. Mosby Elsevier. Eds. Porter, D. and Schon, L. 2008. “The initial treatment for Achilles tendinitis is nonoperative. The majority of symptoms respond to rest; activity modification; improved training techniques; stretching and at times, shoe modifications and heel lifts. Initial treatment should include …At times, a heel lift (one fourth to three eights inch)….”

Noakes “The Lore of Running, Fourth Edition”  Human Kinetics Press. 2003. Noakes feels a shoe with a heel height of higher than 12 – 15 mm and says “most authorities agree that a 7 to 15 mm heel-raise should be added to the running shoes”.

Back To Basics: Tibial Stress Fracture & Frontal Plane Vectors (repost 2008)

The current issue of Medicine and Science in Sports and Exercise (MSSE) has a study which indicates that the frontal plane force vector of the limb is directed more medially (toward the midline of the body) in those who have sufferred tibail stress fractures. The magnitude of forces in the control group were the same as those in the group that had sufferred injury. The conclusion of the authors was that the direction of the forces may be a contributor in the development of tibial stress fractures. This add a specific biomechanical risk factor for tibial stress fractures.

Within a narrow to medium range of normal this may be very significant. At greater deviations from normal, such as with severe genu valgum or varum (knock kneed or bow legged), my guess is that the forces will be too far away from the affected area to matter. So one day another study, with more extremes will have a different result than the current one. Study design and sample populations play a large role in study results.

Studies have already demonstrated the efficacy of the Pneumatic Walker in aiding and speeding healing of tibial stress fractures. Excessive pronation plays a role in overload of the medial muscles of the leg and also will shift the force vectors medially. Well designed custom foot orthotics should effectively shift the vector laterally and could be useful in preventing recurrence. No one factor alone though should be considered enough. Bone density, calcium and Vitamin D needs, and training must be evaluated.

Already, the warnings are in for avoiding too much, too soon and to allow your body, and your bones to adapt to the stresses you want to place them under. Increase your training slowly, gradually, and carefully and make certain to drop back every 2-3 weeks while increasing the training volume (and load).

References:

External Frontal Plane Loads May Be Associated with Tibial Stress Fracture.
Medicine & Science in Sports & Exercise. 40(9):1669-1674, September 2008.
CREABY, MARK W. 1,2; DIXON, SHARON J. 2

Clinical Biomechanics  Volume 19, Issue 1, January 2004, Pages 71-77
The role of selected extrinsic foot muscles during running
Kristian M. O’Connor and Joseph Hamill

Effect of Inverted Orthoses on Lower-Extremity Mechanics in Runners.
Medicine & Science in Sports & Exercise. 35(12):2060-2068, December 2003.
WILLIAMS , DORSEY S. III 1; MCCLAY DAVIS, IRENE 2 3; BAITCH, STEPHEN P. 4

Achilles Tendon: The Missing Link? (repost 2007)

Getting Your Avatar Moving Better Than a Monkey

Dr. Bill Sellers of the University of Manchester has just announced that he has made a computer model that demonstrates that tendons are an important structure to store and return energy. Well, this may be big news for my 70 Priest in World of Warcraft, who soon may be modeled to have a bit more spring in his step. Already, my undead priest is able to walk and dance better than the gnomes can, but he is hardly able to run. Now, what does the announcement mean to the rest of us and what did Dr. Bill say about his computer modeling?

“What we’ve found is that muscles are attached to bones by tendons at the end and these tendons are big springs that store energy. If we make a model without tendons, it turns out that it’s rubbish.” Unfortunately a view of the model indicates that it seems to resemble what I imagine his recent model of 5 dinosaurs moving would look like. Dr. Bill did make the news earlier this summer with his announcement that his computer model of T. Rex showed T. Rex was fast as well as fearsome.

Well, a model in which the knee hardly bends while running, no quadriceps is visible, and the longitudinal arch of the foot (and plantar fascia) is not playing a role in gait is also rubbish. Without a computer model, one can see what happens to the gait in which one has a rupture of the Achilles tendon. There is no active propulsive phase. Erdemir et. al. with Neil Sharkey wrote in JBJS in 2004 about how the plantar fascia may transmit the energy stored in the Achilles tendon to the forefoot. The statement about storage of energy in the tendons was most recently made fairly close to the University of Manchester, in the British Journal Nature by Bramble and Lieberman in 2004. “Collagen-rich tendons and ligaments in the leg store elsastic strain energy during the initial, braking part of the support phase, and then release the energy through recoil during the subsequent propulsive phase. To use these springs effectively the legs flex more in running than in walking…” Further back Cagagna, Thys and Zamboni made similar hypotheses in 1976 and Ker et.al. in 1987 wrote an article titled “The spring in the arch of the human foot” which included the foot within the gait model as a place of energy storage. Certainly the running shoe market will soon include energy return systems which mimic the storage system of the plantar fascia via storage within bending plates of metal or plastic rather than “springs”. Computer models must be made to mimic the system they purportedly model and therefore we need tendons present in the model. In other literature they are often modeled and pictured as being the equivalent of a “spring”.

Please note, there is a statement in much of the lay press indicating that gorillas do not have an Achilles tendon. They do, it is, however, much smaller and shorter than that found in humans.

A debate over who was best able to run fast and at what stage of our evolution could we do this is of interest, but another interesting question is when did we figure out that we could set traps for our prey and not run or make weapons, be it a stick, a spear, or a bow and arrow, that would keep us from having to run quite as fast as our prey. Since our sprinting speed can only be sustained for around 15 seconds, at some point our ancestors found that it is not the sprint that helps us, but our intermediate distance running or our endurance running that will allows us catch up and serve up our prey. And better yet, our brain, which will let us run smart, and perhaps, not have to run much at all. Then all our running can eventually evolve to running for pleasure and less to finding food. Hence the evolution of food down to a power bar or a squeezable container of gel.

It is important also to note that much goes into having an upright bipedal gait and at least as much into having a running gait. While many animals are considered to have adapted to more forms of gait than humans, I’d view it as more than just two forms of gait. Just watch a steeple chaser to see more than 2 in just a few seconds. Well, I wasn’t entirely serious about the steeple chaser. I view our different speeds and distances that we cover as contributing to different gait types. These gaits involve different energy systems to power them. A sprint of 100 meters, a sprint of 800 meters, a mile race, and a marathon employ different aspects of our energy systems to accomplish them. While our speed will not overcome most of our competitors, our sagely wisdom, ability to plan and yes, even our intermediate and distance running will have a tremendous impact.

I also like both computers and computer models. I look forward to seeing a quadriceps, gluteal muscles, posterior tibialis muscles and many other factors added into the computer based simulation. Just a few years ago at the Iowa College of Podiatric Medicine I viewed a work in progress: a simulation of gait using a cadaver limb with the lower limb muscles loaded and pre-programmed to tense at the time in which a normal gait would have them do so. This “action” model nicknamed “Dead Man Walking” was set up so that one could alter the use of the lower limb muscles in a stride. Hopefully more will come of both kinds of studies and those writing about it will describe accurately the work and the words of the author. I plan to seek out more of Dr. Seller’s own words, which are thought provoking, and a bit less of the third party interpretation.

References:

Bramble DM and Lieberman DE (2004) Endurance running and the Evolution of Homo. Nature, 432: 345-352.

Erdemir,A Hamel,AJ, Fauth, AR, Piazza,SJ Sharkey,N
The Journal of Bone and Joint Surgery (American) 86:546-552 (2004)
Dynamic Loading of the Plantar Aponeurosis in Walking
Ker, RF et. al. The spring in the arch of the human foot. Nature 325: 147-149 (1987)

Cavagna GA et. al. The sources of external work in level walking and running. J. Physiol. Lond 262: 639-657.

Hicks JH: The foot as support. Acta Anat (Basel) 25: 34, 1955.

Lapidus PW: Misconceptions about the springiness of the longitudinal arch of the foot. Arch Surg 46:410, 1943.

Ward, E et. al. 2003. In Vivo Forces in the Plantar Fascia During the Stance Phase of Gait. Journal of the American Podiatric Medical Association Volume 93 Number 6 429-442 2003