Thursday, May 11, 2017
Maximalistic Shoes and Their Biomechanics
Maximalist Footwear: A Closer Look at Biomechanical Implications
By Richard L Blake DPM
Figure 1: Hoka One One Maximalistic Shoes
Maximalist footwear has been incredible gift for the protection of the foot. What does it mean? This category of footwear is an experiment of cushion on the walker, hiker, and runner. If we compared to a standard running, hiking, or walking shoe, the foams look oversized. Sometimes this means thicker mid soles, and they’re typically always wider which gives a wider base of support (20-30% wider than traditional). And if we were to summarize the drop from the heel to the forefoot, most maximalist shoes will be 0-8 mm drop shoes are 10-14 mm drop. These new midsole foams also tend to be lighter, initially feeling great, but can lead to durability problems. They can have built in rocker midsoles which are great for some cases of metatarsal issue, and not for others.
If one thinks about this category of shoe the Hoke One One shoe company comes to mind. But who are the players (in no particular order)?
A) Hoka One One
F) Pearl Izumi
H) New Balance
Whereas traditional shoes had ranges in cushion and stability, maximalist shoes can range from very soft to firm, very light to heavy, neutral to stability, 0 heel drop to 8 mm heel drop, flexible or rigid, rocker or no rocker, narrow or wide, etc. From a pure biomechanics standpoint, this new category of shoes presents excellent choices to help her patients.
The purpose of this article is not to help you select individual shoes for your patients. But I will try to help you deepen your relationship with the running stores which sell the shoes. How do we approach this subject? This following 17 criteria can help you with your initial recommendation. I like to think that every athlete, with all the possibilities we have, could benefit from the wearing of a standard shoe sometimes, maximalist shoe sometimes, and minimalistic shoe sometimes. If you believe in the “tissue stress model” for injuries, and if you believe that each type shoe produces different stresses, our athletes may be able to mix up the stresses by alternating shoes in the same way we teach people to cross train. I think it is very important to remember that there are general rules we use, and I will discuss, in the treatment of patients. But, they are only generalizations that tend to work sometimes, always exceptions. The art of it all must be used in your experimentation.
From a podiatrist standpoint, and I have been practicing sports medicine for 35 years, the minimalistic movement taught me 2 great things and reinforced several others. These lessons can be carried over to the maximalist shoes, which share many qualities with the minimalists. These shoes with their poster child Vibram 5 Finger taught me that it was okay to feel the ground again, and that we were probably protecting our patients too much and for too long. They taught me that various shoe categories could be worn at select times to vary the stresses in the body for an activity. And I relearned what physical therapists have been telling me for years, strengthen the foot! I am an isolation type of guy in general, I believe that to strengthen muscles ideally the muscle should be isolated. However, as long as you understand the tissue stress model, and not exercise a muscle past its micro-failure zone, the minimalistic shoes will help strengthen your foot. The minimalistic guys also taught about the strike on the ground. To be safe, a minimalistic shoe wearer should become a ballet dancer with a forefoot strike. I watched so many of my knee and hip patients feel so much better with less heel strike. But, also saw so many of my patients fracture their heel, or develop severe shin splints, from remaining a heel striker. The maximalistic shoe company Altra has all its shoes with zero drop which de-emphasizes heel strike. And both the minimalists and maximalists believe in light as possible and avoiding excess material.
These criteria will represent typically easy evaluation points or other factors relating to their injuries, biomechanics, training experience, and weaknesses. As you evaluate the athlete, using whatever skills and questions you have, categorize them by these 17 criteria, which can help you decide on shoe gear recommendations.
#1 neutral biomechanics
#2 supination biomechanics
#3 pronation biomechanics
#4 poor shock absorption biomechanics
#5 shock absorption needs
#6 type of strike (heel, mid foot, and fore foot)
#7 balance issues (proprioception)
#8 beginning athlete
#9 experienced athlete
#10 low mileage or heavy mileage
#11 stable or unstable surfaces trained on
#12 heel height crucial biomechanics
#13 width crucial
#14 forefoot flexibility crucial
#15 forefoot rigidity crucial
#16 forefoot rocker crucial
#17 need for lightness
So how do we look at the 17 criteria? First of all, I think it should be apparent that no one shoe will be perfect, so switching it up is important. The athlete loves to be involved in this decision making, and can see the validity in these decisions. I think it is important to have our athletes train on different surfaces, use different miles per work out, cross train, and have different shoes for different activities. You can summarize the 17 criteria into 6 main categories:
A) Overall Biomechanics
B) Type of activity for shoe to be worn
C) Injury or weaknesses
D) Type of athlete
E) Special need from shoe
F) Strike pattern
The first 4 criteria should really involve gait evaluation. Any attempt to stand someone up and decide if they are neutral, pronator, supinator, or have poor shock absorption I have not found to work well. But if you can observe the athlete in the activity that they are buying the shoes for, you can usually see if they are neutral, have a tendency to supinate, have a tendency to pronate, or have shock absorption issues.
#1 Are they neutral? This is an observation that is made if they have orthotic devices or not. Basically, you watch them walk and run in what they have been using. If you are going to make them orthotic devices, or dispense OTC inserts, wait until they have those inserts. Too many of our athletes, especially the pronators, were put in anti-pronation stability shoes, even when they were neutralized with orthosis. And do not forget the power of power lacing (also called a runners knot or stability knot). Some pronators or supinators became neutral with just power lacing. The problem lies in then over-correcting someone, thus making them an unstable supinator, from a pronator. We want neutrality in general where the weight is evenly distributed as they roll through their metatarsals. So many of these cushy maximalistic shoes will take the normal motion of pronation at contact and make you a pronator. I have significant number of athletes who only really need their orthotics for these shoes to give them stability. I also have athletes that need ranges of pronation control in 2 or 3 pairs of orthotics in order to wear these shoes for some benefit.
#2 Do they have a tendency to pronate? The subtleties for the pronators lies in the categorization of mild, moderate or severe. And this can be greatly influenced, for good or bad, by whether they wear custom or OTC orthotics. The range of shoes in resisting pronation is so extreme now, that pronation support from different orthotic devices can be needed (as mentioned in #1). I love to grade my orthotics A, B, C, D, and occasionally F for the amount of pronation or supination control I obtained. So, if a few years ago, a runner with plantar fasciitis, who pronated, got symptom relief from a B orthotic device and a stability shoe, is now wearing a super cush maximalistic shoe, and the symptoms are returning, may now need more correction to get to A, or A-, or B+. Yet they may just need some better training guidelines, or just taping and power lacing, or a slight varus wedge under the medial aspect of the orthotic device they already have. Whatever works for them is okay and I love to practice KISS (Keep It Simple Stupid) when I can. And I explain all this to them. They are typically every passionate about their activity, and love this knowledge.
#3 Do you have a tendency to supinate? This can be from pes cavus, weak peroneals, unstable lateral columns, tibial varum, etc. And for the 10-15% of you who are supinators, I have not found over-the-counter orthotics to work well and even custom orthotics (unless designed for supination) can put too much on the arch and throw them laterally. Whereas some pronation is still okay, some supination can be deadly. The same adage is true in both bunion surgery and foot biomechanics: Thou shall not varus! Again the subtleties for the supinators is a categorization of mild, moderate, and severe. For those of you Root trained, or Kinetic Wedge trained, or Maximally Pronated trained, you will understand not to supinate. Maximalistic shoes that are really stacked (some of the Hoka One One shoes I know have a 36 mm midsole) can take a neutral patient, or pronator, and begin to lean outward (especially due to the durability impact of lateral heel strike, the use of orthotic devices for some symptoms, and the need of the shoe to be light and soft). Image 2 shows this tendency in only 100 miles. I would recommend a monthly counter top check of how the shoe is leaning for your patients to do at home. There are 17 plus common pain syndromes associated with over supination. Typically their original symptoms feel better, but they can begin to complain of other symptoms like peroneal, ilio-tibial band, or medial knee compartment from jamming.
Figure 2: The left Hoka One One shoe is leaning out making a pronator into a supinator.
#4 Do you have poor shock absorption? These are the pounders. Some just have too much heel strike. This does not have to do anything about their weight. They can be supinators also, since you need some pronation for shock absorption. Or they can function maximally pronated, it is the motion of pronation that absorbs shock not the position. Some people are good at observing excess shock, sometimes it is how hard a person hits the ground, and sometimes it is just that they have knee arthralgia or hip arthralgia or lower back symptoms and the pounding should be minimized. I think the general concept behind maximalistic is shock absorption.
#5 Do you have shock absorption needs? The ultra-marathoners who wear this shoe type believe the added shock absorption is saving their joints during these long runs. I think by definition if you are an ultra-marathoner, you are a poor shock absorber. You need the extra protection, common sense. But, it may be the runner or walker, with too much cement activities, or some vitamin D deficiency, or other forms of inadequate bone health. It could merely be the novice cross country runner whose bones are not used to the pounding or torqueing.
#6 What type of strike do you have? Is it heel strike, midfoot, or forefoot? For years I have been trying to get my heel strikers to get more solid and stable by landing on their midfoot (really should be whole foot). I would refer them to the website or YouTube videos on Chi Running which is all about mid foot landing and a stable body above your foot. With all the variations you will find in maximalistic shoes in terms of these wide bulky midsoles and uni-bottoms, Chi Running has helped patients land on a more stable surface.
Figure 3: The typical wide out-flared soles which can cause stability issues with heel strikers
I usually have found mid foot strikers the most stable, with the heel strikers and forefoot strikers less predictable. They can be very smooth, or violently unstable, or something in between. I have had to make custom orthotic devices to stabilize the instabilities more in heel strikers or forefoot strikers, and there is less of the foot to use in a forefoot striker.
#7 Do you have balance or proprioception issues? Of course, this can be from many causes. There are 5 levels to a typical single leg balancing evening routine for our patients to work through. You do not have to be in a highly stacked maximalistic shoe with balance issues to enjoy the benefits of the cushion. The photo below shows a several stability, and not too high, Adidas NMD CS1. Or if you or your patient is really unstable and walks on uneven ground, try one of the maximalistic hiking boots.
Figure 4: The Adidas NMD CSI with added stability plugs and lower stack heights.
This puts our discussion into the next group of criteria: the type of athlete you are. As you all know, AMA recently upped its daily walking minimum to 15,000 steps. This is 2 and ½ hours for me, a relatively low walker. But, to my classification, it means all walking to these levels is very athletic. You runners cannot scoff at the walkers as much. It is getting us out of the house, off the couch, and into the roads. Here is where a stable foundation, one where maximalistic shoes can shine with their great shock absorption, can perhaps beat back the onslaught of obesity and diabetes and cardiac conditions. It is another tool is our box, and a good one at that.
#8 Are you a beginning athlete? If you are just starting to walk, have a good pair of maximalistic shoes to wear for your longer walks, and traditional neutral running shoes for your shorter walks. Running shoes in general have more support and cushion than walking shoes in general. With only 50% of people who start a walking program, and 30% a running program, still going in 2 years, it is crucial you take this seriously (and your podiatrist who recommends it). It you cannot find a store with a good selection and exchange rate familiarize yourself with the great surface and ability to experiment with Zappos or RoadRunnerSports.
Figure 5: Good Neutral Shoe from Skechers with great forefoot flexibility and good shock absorption
#9 Are you an experienced athlete? Experienced athletes are typically more aware of their bodies and have a good base of exercise which has strengthened them. They can definitely get away with more training errors, like improper shoes, hurried training programs, etc., since their threshold for overuse injury is higher. Experienced athletes should be very much used to cross training, and already know if they need neutral or stability shoes. I believe all experienced athletes, especially as we age, should get familiar with this latest brand of cushion shoe. It may be of great help in increased stress environments as so many ultramarathons attest. Several of the negatives of being an experienced athlete are 1) may take more risks feeling a bit too invulnerable, and 2) get to set in your ways and not vary things up enough. Maximalistic shoes can be a way to vary a workout, without much psychological change.
#10 Are you low mileage or high mileage? Whatever you do, low mileage is less stressful, and less need for the added cushion of a maximalistic shoe. High mileage walkers, hikers, or runners, need to daily vary the terrain, the distance, and the type of shoes they wear. I know this article is about maximalism, but the group of experienced (more than 3 years) high mileage athletes tend to do great with a workout or two a week with minimalism.
#11 Do you train on stable versus unstable environments? This is where I can get nervous with a stacked high maximalistic shoe with unstable ankles and uneven terrain. The problem typically comes when you did not expect the terrain change, or you were day dreaming. All the maximalistic shoes can accommodate an ankle brace when needed.
Finally, maximalistic shoes allow for a wide variety of individual needs to be met when dealing with injuries. There are times we want heel height or no heel height, very wide or narrow, forefoot flexibility or rigidity, forefoot rocker or not, or very light or standard. There are maximalistic shoes that fit all these specs.
#12 Is the heel height level crucial? Most agree with the minimalists that metatarsal, knee, and sometimes hip pain felt better in a low heel, and Achilles, plantar fascia, and shin splints loved a higher heel. The maximalistics are all over this with cushion and high 8 mm heels and zero drop heels (like in the Altra complete line of shoes).
#13 Is the width crucial? In general, I personally think they are either too wide (Altra line) or too narrow (Hoka One One line), but with power lacing, orthotics, etc., I can typically make it work. Most biomechanics people I know believe the front can be a little loose, as long as the mid part of the shoe is stable on the foot.
#14 Is the forefoot flexibility crucial? The image below shoes the forefoot flexibility test that was standard for traditional shoes. Some maximalistic shoes are very flexible, and this can be an important factor in someone’s injury.
Figure 6: Maximalist Altra Olympus showing good forefoot flexibility
#15 Is the forefoot rigidity crucial? You make the shoe rigid so it acts like a cast. You can have your patients buy a carbon graphite plate, like those sold at Otto Bock, if they already have the shoe you want. The more rigid, the more stable the overall shoe becomes.
#16 Is a forefoot rocker crucial? This is different than just being rigid. It actually allows for the normal roll of the foot like a removable boot. For some conditions, like sesamoid issues, this roll can allow the boot wearer to get into shoes more quickly. It needs a high stack however, so the negatives of some instability and durability issues may be of concern. The removable boots we have our patients wear actually prolong the weight bearing of the heel and forefoot versus traditional shoes sometimes increasing pain in these areas you are trying to fix. Same possibility is present when you use a rocker shoe.
#17 Do you need lightness? This new batch of foams that make maximalistic shoes are light. Who doesn’t love that? Probably great for joints, but watch for durability issues.
 Metzler, Brian, Sole Man: 12 Things About Maximalist Shoes, Competitor.com
 Beer, Brad, Hoka Running Shoe Review-Hype or Helpful?, https://www.pogophysio.com.au/blog/hoka-running-shoe-review/
 McPoil, Thomas G. and Hunt, Gary C., Evaluation and Management of Foot and Ankle Disorders: Present Problems and Future Directions, JOSPT, Volume 21, Number 6, June 1995, pages 385-388.
 Ellingsen, Linda, Barefoot/Minimalist Running Basics, https://www.rei.com/learn/expert-advice/basics-of-barefoot-minimalist-running.html