Wednesday, February 11, 2009

Runners Morphologies

Morphologies and styles of runners

Pronation is natural, and this rolling from the lateral to the medial side of the foot is one of the body's ways of absorbing shock. Overpronation refers to a foot that rolls excessively to the medial side. Footwear makers are keen to provide medial support for their overpronators. Medial posts, described above, are used to increase the firmness and support through the medial area of the shoe. That denser EVA in the medial side of the midsole—as in the dual density EVA in a shoe like the Brooks Adrenaline pictured—is an example of medial posting. There are also unique and proprietary methods used to create medial support, such as Mizuno's Wave, and you'll read about them in our footwear reviews.

This is the opposite of pronation. It's an outward rolling of the forefoot that naturally occurs during the stride cycle at toe-off. Supination—synonymous wtih underpronation—occurs when the foot remains on its outside edge after heel strike. A true supinating foot underpronates or does not pronate at all, so it doesn't absorb shock well. It is a rare condition occurring in a small fraction of the running population.

The shoes of supinators show outsole wear on the lateral side not just at the heel but all the way up to the forefoot (most runners will find their shoes wear on the lateral side at the heel, and the medial side in the forefoot). Typically, underpronators tend to break down the heel counters of their shoes on the lateral side. Supinators should consider running shoes from the "cushioning" and "neutral" categories.
Categories of shoes

With the above as a backdrop, let's use this knowledge to see if we can divine why some shoes are categorized as they are, and what these categories mean.

Motion Control
What do we know of "straight lasted" shoes? They offer support, robustness, durability. What sort of runner might need a shoe like this? Maybe a heavier runner, or an overpronator, or one who is both. A motion control shoe buttresses against overpronation. They are usually the most expensive, heaviest and protective shoes because they employ the most control and stability features. Their downside is weight, and lack of flexibility and suppleness.

Inside of this category are shoes preferred or required by the broadest swathe of runners. Stability shoes usually have a two-density midsole and a stable base of support to reduce overpronation. Inside of this category is the shoe featured in the image, the Brooks Adrenaline, the shoe I've most often worn for training over the past several years. If you marry a "motion control" shoe to a "neutral" shoe, and they mate and have babies, stability shoes are what will pop out.

Cushioned or Neutral or Lightweight Trainer
"Cushioned" is the traditional name for this category, but it is increasingly being replaced by "neutral," because a shoe can wander over into the stability category and still have reasonable cushion. Nevertheless, you're likely to get a softer ride here than in any shoe category, because these shoes are free of the need for any medial or rearfoot stability devices. Cushioned or neutral shoes are preferred by runners who have a good footfall. Here at Slowtwitch, we often refer to them as "lightweight trainers."

Racing flats
These are the lightest, most flexible running shoes. Some racing shoes are half the weight of typical training shoes, but offer much reduced cushioning, protection and durability. Generally, only runners racing at 7-minute pace or faster; who are relatively light; and who have good footfalls (they don't overpronate!) should consider racing flats.

All that established, sometimes it's hard to categorize a shoe. Note that our footwear editors-at-large, Jeroen van Geelen and Peter Beauregard, each review the Brooks Racer ST, even though they were reviewing "neutral" and "racing flat" categories, respectively. Mr. Beauregard notes that this is the "heaviest flat" in his review of racing shoes made by three footwear manufacturers, "weighing in at 8.7 ounces." Mr. van Geelen reviews this shoe as well but, while acknowledging that Brooks considers it a racer, "considering the weight (8.7 oz.), I would say this is more a lightweight trainer. This shoe also runs more like a lightweight trainer."

Tuesday, February 10, 2009

Parts of A Shoe

The parts of a shoe

The last

All shoes are built on a last. This is the heart of a shoe. It is a piece of plastic, metal, or wood, and its contour determines the shape and size of the shoe. The etymology of the word is "laest", the Old English word for footprint. There are three basic shapes: straight, semi-curved; and curved; but all three shapes vary from company to company as each company has its own lasts. Semi-curved is by far the most popular and most runners do well in a semi-curve-lasted shoe.

A straight-lasted shoe features a straight-shaped sole with little indentation at the arch. A straight last is appropriate for the overpronator with a flexible, flat arch. It helps to control inward rotation. Shoes with a straight last offer the most medial support, and "motion control" shoes tend to be built with a straighter last than stability shoes. A stability shoe is more likely to have a semi-curved last. Most racing shoes are built on a curved last.

The downsides of straight-lasted shoes is a lack of flexibility; they weight quite a bit; and they're less able to deliver a performance run. This isn't a speedwork shoe, or a tempo run shoe. Curved or semi-curve-lasted shoes are what you want for tempo runs, fartlek, speedwork. But, they break down quicker if you're an overpronator, and your orthotic, if you use one, will "help" break down the medial side of a curve-lasted shoe.

The term "last" can be confusing, because it can also refer to how the upper is attached to the midsole. You'll hear three terms used: slip-lasted; board-lasted; and combination-lasted. A slip-lasted shoe is made by sewing the upper into a shape that resembles a moccasin. This construct is then glued directly to the midsole without any board in between. These are flexible shoes with lots of cushioning and, on balance, little motion control.

Board lasted shoes have a sturdy insole fiberboard running the entire length of the foot bed. This type of construction provides the greatest stability. But shoes of this construction are rare nowadays because of weight, and lack of flexibility.

A combination-lasted shoe is stitched in the forefoot and glued in the rearfoot to that fiberboard. While slip-lasting is the most common construction, Asics is one brand that combination-lasts many of its shoes.

Some runners believe a combination-lasted shoe is the most stable and most supportive for orthotics, because the fiberboard mates nicely with the orthotic's heel. To determine which type of lasting the shoe has, remove the insole (also called the sock liner). If there's stitching in the rearfoot, it's slip-lasted. If you see that fiberboard on top of any of the stitching, it's combination-lasted.
This is the outer sole of a shoe—the bottom of the shoe. It's the layer of the shoe that contacts the ground.

Carbon Rubber, a common outsole material, is rubber with a carbon additive to increase durability. It is denser and heavier than blown rubber, and often used in high impact areas.

Blown rubber, a common outsole material, is rubber mixed in some fashion with air. Blown rubber yields a relatively light, cushier outsole, but suffers in durability compared to carbon rubber. Blown rubber is a process most triathletes rely upon: it's what their wetsuits are made of (though wetsuit rubber is much lighter and softer than what is used in the outsoles of running shoes). It's not inconceivable that your wetsuit, your shoe's midsole and EVA outsole, your swim goggle's liner, and your cycling shoe winter booties, are all made of material from the same factory.

Many outsoles use a combination of blown rubber in the midfoot and forefoot—for a lighter shoe with a cushier ride—with carbon rubber in the rearfoot for added durability.

This is the area of the shoe between the upper and outsole. It's primarily responsible for the shoe's cushioning. Most midsoles are made of foams: either EVA (ethylene vinyl acetate) or polyurethane. EVA is lighter and more flexible than polyurethane, but it also breaks downmore quickly. Many midsoles also have additional cushioning elements such as air and gel.

Just as there are proprietary types of blown rubber used by different triathlon wetsuit manufacturers, there are proprietary types of EVA in the marketplace, such as Nike's Phylon and Brooks' Substance 257. Whether in wetsuits or in running shoes, some proprietary designations are more market- than substance-specific, and some really are substantive and provide specific efficacy. Adidas adiPRENE, Brooks HydroFlow, New Balance AbZORB, are additional examples of proprietary EVA.

Medial posting
"Medial" in this context refers to the inner side (the arch side) of a shoe. Lateral is the corresponding term referring to the outside edge of a shoe. Shoes rarely need much extraordinary support on their lateral sides, because most runners pronate, that is to say, their feet roll to the inside. Arch supports, and orthotics, are examples of products designed to buttress and support the foot on the medial side.

EVA is the most common midsole compound used in running shoes. This shock-absorbing foam is soft, light, and flexible. It can be made in variable densities: the more dense the EVA, the harder the ride, but the more supportive for over-pronators. For this reason, many footwear makers employ two densities of EVA, with the firmer density on the medial side of the midsole. This dual-density EVA combines a smooth, supportive ride with a barrier to compression on the shoe's medial side. This technique is called a medial post.

Other parts of the shoe
The "upper is the leather or mesh material that encloses the foot.

"Flex grooves" are midsole and outsole notches to allow the shoe to bend and flex properly with the natural motion of the foot improving forefoot flexibility at toe-off.

The "heel counter" is a device—often a piece of leather, or a plastic cup—forming the back of a shoe. Its job is to reinforce the heel and prevent excessive heel motion. The heel should fit snugly without being too tight. If it's too wide, the heel will slip in and out of the shoe and cause blisters. Women, in particular, often have narrower heels than men and require a narrow heel counter, common in some brands such as Saucony.

The "sock liner" is the removable insert added to cushion and protect your foot from the shoe's midsole. Orthotics, when used, replace sock liners.

The "toebox" is the area of the shoe that encases your toes.

Monday, February 9, 2009

Pronation (loose)/Supination (rigid) & Gait Timing

January 27, 2009

A journey of 1,000 miles starts with "that first step." So it is with sports.

It starts with the feet -- running, jumping, starting, stopping and balancing. Virtually all movement involves your feet and their ability to do some amazing things. Often taken for granted, the foot is a mechanical marvel designed to perform some specific functions during the so-called gait cycle. The terms pronation and supination describe normal positional changes in the foot and ankle that we'll define as follows: every step you take when walking can generate about half to two-thirds of your weight up the feet and legs. When running or jumping, those forces can be multiplied by three to five times. The ability of the foot to dissipate these forces as the body's first major shock absorber is extremely important.

Pronation is the positional changes that the foot attains to loosen up the joints under the ankle to allow this shock absorption. Pronation also allows the foot to adapt to the ground surface. Once the body passes over the foot this loose bag of bones (pronation) becomes a stable structure as the foot becomes a rigid lever to propel the body forward. This lever position is called supination. Many so-called overuse injuries like plantar fasciitis (arch and heel problems), shin splints, runners or jumpers knee tendonitis are related to abnormal forces associated with foot position changes.

Flat feet, many times associated with too much foot pronation, can cause the expected push off or supinated phase to be either too late or absent totally. Abnormal strain to the structures of the feet and legs can result from this. Since inward rotation of the lower leg accompanies pronation of the foot, problems with shins and knees can result from this increased torque caused by excessive foot pronation.

Examination of the individual standing, walking or running can reveal specifics about these foot positions and mechanics. Identifying weak links in the alignment of the foot, ankle, knee and hip structures can be very valuable in preventing overuse injuries. Stability tests like single leg balance and squat positions can give good information.

Why does one person over pronate and can be prone to overuse injuries while another functions more normally and is less prone? Often it's genetics or inherited foot structure. Blame your parents if you have excessive pronation. Women, because of their hormonal make-up, have a tendency to be loose jointed. Because of this laxity of ligaments, also often inherited, excessive pronation can be a problem even with good foot structure. High arch feet can also cause problems related to over supination. Limited shock absorption can cause strain to ankles, knees, hips and back. This foot type also is often inherited from mom and dad.

By far the best method to properly deal with these timing of foot position abnormalities is with the use of prescription in shoe orthotics. Made from positional molds of the feet, these devices allow the optimum alignment of the foot and lower legs to be obtained. Orthotics can help to get the feet in the proper position at the proper time. If the foot supinates (becomes a rigid lever) at the right time, then speed, stability, balance and function improve. When excessive pronation is controlled, strain to the foot, shins and knees are lessoned.

In the past, orthotics were often confused with arch supports. The thinking was that supports would "hold up" flat feet. If the feet didn't hurt, they weren't considered. Today, we understand that it's not support but alignment and positioning that counts and that's the role of prescription orthotics. Often people, athletes or not will ask, do I need orthotics? It's better to ask would I benefit? Almost all athletes do.

Friday, February 6, 2009

Ankle Sprain Overview

The ankle joint, which connects the foot with the lower leg, is injured often. An unnatural twisting motion can happen when the foot is planted awkwardly, when the ground is uneven, or when an unusual amount of force is applied to the joint. Such injuries happen during athletic events, while running or walking, or even during everyday activities such as getting out of bed.

* The ankle joint is made up of three bones.

o The tibia is the major bone of the lower leg, and it bears most of the body's weight. Its bottom portion forms the medial malleolus, the inside bump of the ankle.

o The fibula is the smaller of the two bones in the lower leg. Its lower end forms the lateral malleolus, the outer bump of the ankle.

o The talus is the top bone of the foot.

* Tendons connect muscles to bones.

o Several muscles control motion at the ankle. Each has a tendon connecting it to one or more of the bones of the foot.

o Tendons can be stretched or torn when the joint is subjected to greater than normal stress.

o Tendons also can be pulled off the bone. An example of an injury of this type would be an Achilles tendon rupture.

* Ligaments provide connection between bones. Sprains are injuries to the ligaments.

o The ankle has many bones that come together to form the joint, so it has many ligaments holding it together. Stress on these ligaments can cause them to stretch or tear.

o The most commonly injured ligament is the anterior talofibular ligament that connects the front part of the fibula to the talus bone on the front-outer part of the ankle joint.

Ankle injuries can be painful and can make it difficult to carry out daily activities.

Thursday, February 5, 2009

Ankle Braces Reduce Risk of Ankle Injuries by 3 Times

The Efficacy of a Semirigid Ankle Stabilizer to Reduce Acute Ankle Injuries in Basketball
Sitler M, Ryan J, Wheeler B, et al: Am J Sports Med 22(4): 454-461, 1994
"This randomized clinical study was designed to prospectively determine the efficacy of a semirigid ankle stabilizer in reducing the frequency and severity of acute ankle injuries in basketball." The results indicate that the "use of ankle stabilizers [Sport-Stirrup] significantly reduced the frequency of ankle injuries… Non-braced players had three times the risk of the control players for sustaining an ankle injury." The data also showed that "wearing the ankle stabilizer did not affect the frequency of knee injuries, [and the] attitude toward ankle stabilizer use improved as use of the stabilizer increased."

Wednesday, February 4, 2009

Aircast Ankle Stirrup

Air-Stirrup® Ankle Brace
Since 1978, the Aircast Air-Stirrup Ankle Brace has been the "standard of care" for the functional management of ankle injuries and has been cited in over 100 medical journals for its superior performance in helping to heal ankle injuries. Each Aircast Ankle Brace features anatomically designed shells lined with the patented Duplex™ aircell system. This exclusive system incorporates two pre-inflated overlapping aircells, distal and proximal, that provide support and produce graduated compression during ambulation. The compression promotes efficient edema reduction in addition to helping accelerate rehabilitation. All Air-Stirrup Ankle Braces (except for the pediatric model) come with a patient guide providing information on brace application and optional rehabilitation exercises. The Standard (Large), Training (Medium), and Small size Ankle Brace is available individually or as part of an Ankle Sprain Care Kit™. The Pediatric Ankle Brace is designed for children 2 to 6 years of age and is ideal for ankle stabilization in hemophilia patients. Extra long straps are available "” contact Customer Service for more information.

Tuesday, February 3, 2009

$990 for Foot Orthotics! Amazing Podiatrists

Woman cries foul over podiatry bill
by Frank Donnelly
Sunday January 25, 2009, 10:26 AM

STATEN ISLAND, N.Y. -- She thought she was getting a free callus clip and a mug.
But an Oakwood woman's visit to a New Dorp podiatry office last summer turned out to be a very expensive pain in the foot.

Ashley Castagna's medical insurance carrier was billed $3,235 for the 20-minute treatment she says she received at A Call Away Foot Care. The office visit, according to an advertisement Ms. Castagna and her mother, Sandra, showed the Advance, was supposed to be gratis.

Yet Ms. Castagna's insurance carrier was charged for it, including $1,550 for five surgical procedures, according to a billing statement that the Castagnas provided. All the doctor did, Ashley Castagna said, was shave part of a callus, take molds of her feet and write a prescription for foot cream.

While their insurer has paid $616, the Castagnas were told they're on the hook for $224.

"When I got the bill I was so livid about it," Sandra Castagna said last week during an interview in her home. "My daughter never had one surgery, let alone $3,200 of surgeries."

Ashley Castagna, 21, is a college student who lives at home.

Doctors at A Call Away Foot Care, a cramped storefront office off Hylan Boulevard, did not return several messages left last week, both in person and on the phone, seeking comment.

Ashley Castagna said she visited the podiatry office on New Dorp Lane on June 28 after her mother saw an advertisement with a coupon for a free office visit in a local weekly shopping tabloid. Valued at $350, the treatment includes "cutting nails, calluses, corns, whirlpool, moisturizing foot massage, routine care" and "a free gift mug," the ad says.

Ashley Castagna said she presented the coupon when she visited the office, but was told she didn't need it. She then filled out a form, which included her medical insurance information. The policy is in her father's name.

"I just assumed it was standard practice," she said.

Nobody said she'd be charged for the visit, and she was not asked for an insurance co-payment, she said.

Ms. Castagna said she was with the doctor about 20 minutes. During that time, he shaved a section of callus, took a mold of her foot for orthotic shoe inserts and wrote a prescription for a moisturizing cream. She said she had not complained of any pain in her feet and was given a mug before she left the office.

Her mother picked up the inserts a few weeks later after the doctor's office called to advise they were ready. In fact, Sandra Castagna also picked up inserts for herself. She said she had visited the office with a coupon about two weeks before her daughter and received similar treatment. Both women believed the orthotics were free.

Sandra Castagna later returned five times to receive cortisone shots in her aching right heel. She said she paid a co-payment for each injection, but not for the initial visit, which was supposed to be free. She has not received a statement from her insurance carrier for any of her visits.

To her surprise, however, Cigna HealthCare recently sent a benefits statement for her daughter's visit. It listed charges from the podiatrist's office of $1,550 for five surgeries, $250 for physician care and $990 for prosthetic devices. Along with other costs, it totaled $3,235.

Cigna agreed to pay $616 and said the Castagnas owed a balance of $224.

Sandra Castagna couldn't believe it.

"I was irate," she said.

She called the podiatrist's office, but received no satisfaction. All a receptionist told her is that anytime a doctor touches the foot, it's considered a surgery, said Mrs. Castagna.

"She didn't even try to say it was a mistake," Mrs. Castagna said.

Steaming, she told the woman, "You guys are totally screwing people."

Mrs. Castagna said she then called Cigna and was told the company will investigate.

Kathleen Keenan, a Cigna corporate spokeswoman, said the company has "the appropriate people" probing the matter. She declined to elaborate, citing federal and state privacy laws.

Ms. Keenan added that Cigna encourages its members to discuss potential costs with health-care providers and to contact the company to determine what coverage, if any, is in effect, before receiving treatment.

Mrs. Castagna said she has no intention of paying the bill.

"It makes me so angry," she said. "[Ashley] didn't have anything done to her foot."

Monday, February 2, 2009

Nail-Patella Syndrome/Solid Ankle Foot Orthosis

Nail-patella syndrome, skewfoot.
The patient received her previous SAFO on 10/05/2000. Her mother stated that is was leaving marks on her skin; however, she did not bring the brace with her today. It has not been quite 6 months; therefore, we are going to try to adjust the old one when she brings it in later this week. I did cast the patient today for a new brace, which will be made when she is no longer able to wear the old one. She is a 3-year-old female. The patient has no known allergies. She is not taking any medication, and she is active community ambulator. She has not had any surgery.
On weight bearing, the patient pronates at the midfoot and her forefoot is adducted. Her heel is in valgus but correctable. She can get to 90 degrees; however, her forefoot angle has approximately a 15-degree varus, and she then pulls into adduction. She does not have skin breakdown. She is having difficulty with her medial malleolus. There is a callus that has built up. Her mother stated that this is from the brace. The casting procedure went well.
Fabricate left SAFO. Casting and measurement.
We will see the patient at the end of the week for adjustments to her old brace to enable her to wear it for a longer period of time.