Adult acquired flatfoot or posterior tibial tendon dysfunction or progressive collapsing foot deformity?

Which one is the correct name? There is a lot of discussion going on as to which is the more appropriate name. There are merits for each name.

A lot of it comes down to what is the primary pathology and if it is a primary problem of the posterior tibial tendon or is the driving factor and the primary structures that are involved are more than just that tendon, such as the spring ligament.

This topic has been ligated here.

Is ‘Overpronation’ a problem or not

This gets debated a lot. The views are mixed.

The issues are:

  • yes, pronation is a normal healthy motion
  • yes, there is no definition or consensus as to what is normal and what is overpronation
  • yes, plenty of people overpronate and get no problems
  • yes, other overpronate a small amount and gets lots of problem
  • yes, there are multiple causes of overpronation, so there is going to have to be multiple different treatments. One size is not going to fit all.
  • yes, there are too many who consider themselves experts in this when they have no idea what they are talking about.
  • yes, stick to what the consensus of the preponderance of the research says on the topic and not commentary in social media

Mathematician identifies new tricks for the old arch in our foot

Schematic of the foot skeleton showing the arches and typical loading pattern during locomotion

Press Release:

  • A stiff mid-foot is essential for withstanding excessive force when pushing off on the ground for walking and running
  • The arch along the length of the foot was believed to be responsible for mid-foot stiffness. Now, a research collaboration between the University of Warwick and two other universities has illustrated the greater importance of a lesser studied foot arch – the transverse arch.
  • Our research opens new ways to study the foot for future researchers on foot health. Even the definitions of flatfoot are based upon the longitudinal arch and do not consider the transverse arch. Our work throws these standard practices into question but more work is needed to know how to update them.

Walking and running subjects our feet to forces in excess of body weight. The longitudinal arch of the feet was thought to be the reason the feet do not deform under such load. However, researchers from the University of Warwick, Okinawa Institute of Science and Technology Graduate University in Japan and Yale University have illustrated that the transverse arch may be more important for this stiffness.

Past theories of the foot stiffness look at the longitudinal arch, however in the paper ‘Stiffness of the human foot and evolution of the transverse arch’ published today, the 26th of February in the journal Nature, researchers from the University of Warwick working in collaboration with Yale University and OIST Graduate University, propose the transverse arch may play an equally important role.

The collaboration found that the transverse arch is a bigger source of foot stiffness than what was found due to the longitudinal arch in previous work. They also discovered that the transverse arched evolved to become almost human-like over 3.5 million years ago.

This collaboration between Dr Shreyas Mandre, from the Department of Maths at the University of Warwick, Professor Mahesh Bandi, from the Nonlinear and Non-equilibrium Physics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) and Professor Madhusudhan Venkadesan, from Yale University was funded by a Young Investigator award by the Human Frontiers Science Program.

The authors say that this research motivates further work into the role of the transverse arches in the disciplines of podiatry and evolutionary anthropology. These insights could also inspire new designs for prosthetic and robotic feet.

The role of the transverse arch may be understood in simpler terms by looking at a thin paper sheet. When the short edge is held flat, the sheet is floppy and droops under a little weight. But curl the edge a little and even 100 times as much weight is not excessive.

“Flat thin objects like paper sheets bend easily, but are much difficult to stretch,” Dr. Mandre explains. “The transverse curvature of the sheet engages its transverse stretching when attempting to bend it. This coupling of bending and stretching due to curvature is the principle underlying the stiffening role of the transverse arch.”

But because the foot serves multiple mechanical functions, its structure is more complicated than the paper sheet. Therefore, “flattening” the foot to test the hypothesis of curvature-induced stiffening may have unidentified confounding variables. To overcome this difficulty, the researchers ingeniously disrupted the underlying principle while keeping the transverse arch intact.

“Understanding of the underlying principle enabled us to build mechanical mimics of the foot comprising springs that imitated the elastic tissue of the foot. Disrupting the transversely oriented springs in these mimics had the same effect as flattening them,” explains Ali Yawar, a co-author of the study.

“We disrupted the underlying principle of curvature-induced stiffening in human cadaveric feet by transecting the transverse tissue, which reduced the mid-foot stiffness by nearly half,” said Carolyn Eng, another co-author of the article. In comparison, experiments in the 1980’s on disrupting the stiffening mechanism due to the longitudinal arch only showed a reduction in stiffness by about 25%.

This research also injects new interpretation of the fossil record of human ancestral species, especially pertaining to the emergence of bipedalism. The researchers formulated a measure of the transverse arch to accounts for variations in the length and thickness of the feet. They used the measure to compare related species such as the great apes, human ancestral species and some distantly related primates.

“Our evidence suggests that a human-like transverse arch may have evolved over 3.5 million years ago, a whole 1.5 million years before the emergence of the genus Homo and was a key step in the evolution of modern humans,” explains Prof. Venkadesan. It also provides a hypothesis for how Australopithecus afarensis, the same species as the fossil Lucy, thought to not possess longitudinally arched feet, could generate footprints like humans that were discovered in Laetoli

Going Barefoot: Strong ‘Foot Core’ Could Prevent Plantar Fasciitis, Shin Splints, and Other Common Injuries

Press release:

As your cold-weather footwear makes the seasonal migration from the back of your closet to replace summer’s flip flops and bare feet, don’t underestimate the benefits of padding around naked from the ankles down.

Barefoot activities can greatly improve balance and posture and prevent common injuries like shin splints, plantar fasciitis, stress fractures, bursitis, and tendonitis in the Achilles tendon, according to Patrick McKeon, a professor in Ithaca College’s School of Health Sciences and Human Performance.

The small, often overlooked muscles in the feet that play a vital but underappreciated role in movement and stability. Their role is similar to that of the core muscles in the abdomen.

“If you say ‘core stability,’ everyone sucks in their bellybutton,” he said. Part of the reason why is about appearance, but it’s also because a strong core is associated with good fitness. The comparison between feet and abs is intentional on McKeon’s part; he wants people to take the health of their “foot core” just as seriously.

The foot core feedback loop

McKeon describes a feedback cycle between the larger “extrinsic” muscles of the foot and leg, the smaller “intrinsic” muscles of the foot, and the neural connections that send information from those muscle sets to the brain.

“Those interactions become a very powerful tool for us,” he said. When that feedback loop is broken, though, it can lead to the overuse injuries that plague many an athlete and weekend warrior alike.

Shoes are the chief culprit of that breakdown, according to McKeon. “When you put a big sole underneath, you put a big dampening effect on that information. There’s a missing link that connects the body with the environment,” he said.

Muscles serve as the primary absorbers of force for the body. Without the nuanced information provided by the small muscles of the foot, the larger muscles over-compensate and over-exert past the point of exhaustion and the natural ability to repair. When the extrinsic muscles are no longer able to absorb the forces of activity, those forces are instead transferred to the bones, tendons, and ligaments, which leads to overuse injuries.

It’s not that McKeon is opposed to footwear. “Some shoes are very good, from the standpoint of providing support. But the consequence of that support, about losing information from the foot, is what we see the effects of [in overuse injuries].”

Strengthening the foot core

The simplest way to reintroduce the feedback provided by the small muscles of the foot is to shed footwear when possible. McKeon says activities like Pilates, yoga, martial arts, some types of dance, etc. are especially beneficial.

“Anything that has to deal with changing postures and using the forces that derive from the interaction with the body and the ground [is great for developing foot core strength],” he said.

McKeon also described the short-foot exercise, which targets the small muscles by squeezing the ball of the foot back toward the heel. It’s a subtle motion, and the toes shouldn’t curl when performing it. The exercise can be done anywhere while seated or standing, though he recommends first working with an athletic trainer or physical therapist to get familiar with the movement.

He notes the exercise seems to have especially positive results for patients suffering from ankle sprain, shin splints, and plantar fasciitis. It’s even been shown to improve the strain suffered by individuals with flat feet.

The payoff could be more than just physical, as there could be financial savings. With strong feet, McKeon suggests that – depending on the activity – consumers may not need to invest hundreds of dollars in slick, well-marketed athletic sneakers (though he doesn’t recommend going for the cheapest of cheap sneakers, either). People with a strong foot core can actively rely on the foot to provide proper support, rather than passively relying on the shoes alone.

“You might be able to get a $50 pair of basketball shoes that don’t have the typical support that you’d expect. Because you have strong feet, you’re just using the shoes to protect the feet and grip the ground,” he said.

The easiest way to get started on strengthening the small muscles of the foot, though, is to kick off your shoes in indoor environments.

“The more people can go barefoot, such as at home or the office, is a really good thing,” McKeon said.