Long distance thru hikes and feet growth / swelling

[Bob Gross]

"Had that experience about 30 years ago. The Argentine government required stress EKGs (while on treadmill) in order to get permits to climb Aconcagua (just shy of 23,000 ft)."

Interesting.

They did not even mention that 18 years ago.

–B.G.–

[Billy Ray]

Anyway, the point is that Roger is right… The medical community, whether research or clinical, does not see the super fit people… except for maybe the ones that specialize in sports medicine… and that's a very small percentage I would think

Billy

[Jennifer Mitol]

A great deal of the medical research and literature published on stress fractures, bone health, etc comes from the military, NASA, etc. While on one hand you're right that fit people don't need as much care in terms of diabetes management, heart disease, gallbladder disorders, etc, the fact is that about half my patients are ultra marathoners, marathoners, mountain bike racers, cross fitters and soccer players, and now where I practice I have a huge population of military special forces guys. I'm an orthopaedist, and yes on one hand I have the obese arthritic old men and the frail little ladies with their osteoporotic fractures…but honestly, I see just as many problems in the musculoskeletal realm with the uber fit ones.

[David Thomas]

>"I see just as many problems in the musculoskeletal realm with the uber fit ones."

I don't doubt that, Jennifer.

I notice that you don't list hikers among your frequent flyers.

Per mile or per 1,000 calories burned, how do injuries from running, hiking, bicycling, swimming, tennis, and basketball stack up?

The main reasons I mostly hike are that I enjoy it, it is reflective time for me, and I hate to sweat. But I also like the (presumed by me) lower injury rate. Per mile, running has at least 20x the stress / over-use injuries and bicycling has >100x the ER visits (I never hit my head or got road rash while hiking).

[Billy Ray]

Jennifer,
Could it be that you and your ilk (professionals in the medical community who see a hi percentage of fit people)are still a very small minority of the medical field. I would bet so.

Billy

[David Thomas]

Billy: She is in a small subset of the broad medical community. Half of medical costs are in end-of-life care and most specialities see people with risk factors like poverty, smoking, poor diet, and violent crime.

I know a number of people (all women, now that I think about it) who went into PT specifically because there is a younger, more functional clientele.

[Greg Mihalik]

Billy – Be careful using those big words …

[Billy Ray]

Greg,

You're right… I should look up works like 'ilk' before I use them so's I don't go an' embarrass my own self…

Billy

[Roger Caffin]

You know, looking at the X-ray Jennifer showed, and thinking aboput a diagram I had seen of 'heel spurs', the following thought has crossed my mind.

The textbooks all say that we stop bone growth shortly after puberty. Bones just won't grow after that. Well, what would you call heel spurs and that spike out the back of the heel? Me, I would call both of them bone growth. Stress -induced maybe, but growth nonetheless.

I am not a medico at all; I am a physicist. Sure, physics has lots of text books and theories. But you know what really excites a physicist (professionally, that is!)? When the new experimental data conflicts with the text books and theories. You see, while we have theories, we know that those theories are incomplete; that they are not the full story. Witness the revolution when Einstein broke Newton's Laws of Motion.

Recently Peter Higgs predicted a new boson using the current Standard Model for nuclear particles, and the Large Hadron Collider (a billion dollar machine at CERN) was used to search for it. They think they found it, which was a cause for much GLOOM. Er, gloom??? Yeah, because what many physicists were hoping for was that something unexpected would be found instead – to launch a new and better Standard Model!

So while I know the medical text books are not keen on the idea that 50-year-old foot bones might grow under an extreme cyclic high-stress regime, I also know that very little real data exists covering that edge of the field. I also know that we have widespread experimental data that many thru-hikers' feet have grown significantly during long walks.

So I feel free to challenge the status quo.

Cheers

[Bob Gross]

Roger, in many cases, a heel spur is just a piece of soft tissue that has become calcified. So, it shows up on an xray to be similar to bone, and where the heel spur interferes with softer tissues, some pain may happen.

–B.G.–

[Roger Caffin]

Hi Bob

> in many cases, a heel spur is just a piece of soft tissue that has become calcified.
Ok, but maybe some variant of this is making feet grow wider? I do not know, but I am asking.

Cheers

[Bob Gross]

Wider? Not that I know of. I think that heel spurs tend to occur where the soft plantar fascia connects to the heel. One skier friend had it go the other way.

Otherwise, several of my hiker friends find that their feet normally widen out over time, and this is a natural function of age and time and distance traveled with a heavy pack. It is a bit like the slight lengthening that you can get from fallen arches, but it affects the width. The effect can be mitigated through proper ultralightweight backpacking techniques, which is why we are here in the first place.

–B.G.–

[Jennifer Mitol]

Wow Roger you really want to think that your foot bones grow longer, don't you??

All of the bones in the front part of your feet are "long" bones: the metatarsals and the phalanges (toes). Long bones have a very established growth pattern, and this is what I have been talking about – they will not grow longer.

What heel spurs, and that heel bump are is called exostosis…or osteophytes. These are abnormal growths and yes, they are your body's response to stresses. They are NOT actual bone lengthening. You get them in your knees, hips, etc. They generally are painful (but not always). And they are just as common in fit people as sedentary ones.

And I never said bones don't change…they are very active, live tissues that adapt in both good ways and bad. But the length of a long bone does not change…think about it…the ends of the bones are covered in very complex hyaline cartilage that does not heal and does not grow either (but we're working on that!!), the only place the growth would take place would be in the middle of the bone. Which, as you learned from that textbook, does not happen.

Osteophytes, on the other hand, happen when the hyaline cartilage in the joints breaks down; your body's response is to try to dilute force by enlarging the surface area. The bone spurs you see in that previous X-ray are indeed calcifications of the tendons themselves, not any true lengthening of anything. It's actually a shortening of the elastic component of the tendon…so not a good trade at all.

[Stuart R]

Jennifer – you have the patience of a saint.

[Diane “Piper” Soini]

I can say that after two long distance (3 months) hikes, my arches are as high as ever. High enough that I cannot even feel the arch on a pair of Chaco sandals. High enough that I've actually been complimented on how high and strong my arches appear.

My feet aren't any longer than they were before, but they are a lot wider. There is space between my toes that didn't used to be there. I also do not tolerate shoes that compress my forefoot at all.

If there were more shoes that actually fit my feet, I would still wear a size womens 7 like always, but because they make them all too narrow in the forefoot I struggle to find shoes I can wear and end up with mens size 8, which are quite a bit bigger than my foot.

[Diane Pinkers]

I've been reading this with some interest, as I'd like to do a thru-hike one day, and worry about the toll on my feet.

As a disclaimer, I am a medical professional, but I am a veterinarian. Bone growth in domestic animals is very similar to bone growth in people–Jennifer has been doing a fantastic job trying to explain the physiology to you folks. "Growth" and "change" are very much 2 different things: Bones have to be able to repair themselves, otherwise they would not heal from a fracture. However, once they repair the original damage, they do not continue to grow, and grow, and grow–that would be bone cancer.

Someone asked about gigantism a few responses back. Those individuals have an abnormally high amount of growth hormone during puberty–their bones never close at the growth plates, and keep elongating. This is usually due to "benign" tumors of the pituitary gland, the master gland that coordinates activity with the other endocrine organs–organs that release hormones into the bloodstream. Part of proper puberty is to oversee the appropriate shut-down of the growth plates at the right time, so that the skeletal structure ceases to grow, and instead goes into maintenance and repair.

If an individual has too much growth hormone as an adult, it leads to acromegaly. These individuals have many of the same organ issues and symptoms as gigantism, but they do *not* display the same enlargement of the skeleton, because the tumor occurs after the bone plates have closed, and the skeletal structure is no longer growing.

If growth plates are closed, the bone will not continue to grow longer. This can actually lead to problems, if you have a pair of bones together, such as in the forearm–radius and ulna. If the growth plate of the radius is damaged in a young, growing animal, and closes prematurely, the ulna will continue to grow, producing a twist in the limb that later requires bone-shortening surgery to correct. If bones could lengthen under stress, this would be an ideal time for it to happen–but it doesn't.

As far as measurements, the whole debate is not *whether* feet enlarge, but what tissue is involved. You would need an MRI to see that, I think–CT scan or radiographs would not have the soft tissue detail. However, you wouldn't need an MRI at the trailhead, merely someone willing to get off the trail for a day or two, and a friendly hospital/radiology unit willing to let you jump in on a moment's notice, or at least within a day or three. There are mobile MRI units that service underequipped communities in rural areas. Measurements would be nice, too, but really it's about what tissues are responding to the stress.

[Roger Caffin]

> Jennifer – you have the patience of a saint.

Oh, I agree. :-)

OK, bone growth per se is unlikely to be happening, although some remodelling might.

But so many walkers find their feet get significantly wider, on a permanent basis. And so many of these walkers feel they have enough data to say their arches have NOT dropped at all. How about we start with these as facts, and ask what is going on?

> the only place the growth would take place would be in the middle of the bone.
> Which, as you learned from that textbook, does not happen.
Well, not quite so fast. I am quite willing to accept that growth in the middle of the long bones has not been observed in the vast majority of the average sedentary population. I am less sure that the medical profession has enough data on extreme cases to be really sure about them.

What I have read (which is not much) is that bone remodelling proceeds quite happily, especially when bones are stressed. Is a change in length of a few percent entirely out of the question? I did not think that physiology was that tightly constrained.

Diane suggested that it is the tissue between the bones – what do we know about this?

Cheers

[Diane Pinkers]

Actually, Roger, physiology is *very* tightly constrained, because without every system working together properly, you have an unorganized, unregulated organism. When tissues grow abnormally, without proper regulation–that's cancer. The mechanisms that tell the cell "Ok, you've repaired the damage, you can stop now" get damaged, and no longer function properly. We have yet to plumb the depths of How the regulation happens entirely, but we do know that It Happens.

As for "a few percentage points"–it all has to agree. If my first metatarsal bone is 10 cm long, and it lengthens by 3%, then it has lengthened by 3 mm. The other metatarsal bones in the long part of the foot have to accommodate that stretch, or grow proportionately, because they are all biomechanically linked. The tendons that connect muscle to bone have to stretch to take up that length, the ligaments that connect bones across joints have to accommodate that stretch, the blood vessels that course over it have to stretch, the skin, everything. Some tissues are more elastic than others, and wouldn't even flinch, but connective tissue does not repair itself well, nor is it particularly elastic. Cartilage even less so–once you damage hyaline cartilage, it is never the same, those cells don't hardly repair at all.

When you engineer a mechanism, doesn't it have precise tolerances, which if not produced don't allow the mechanism to function? Just because it's a biological mechanism doesn't mean it doesn't have precise tolerances. When those tolerances are exceeded, malfunction, pain, swelling, etc occur.

[Billy Ray]

I think this thread is making the bones in my head swell :)

Billy

[Roger Caffin]

Hi Diane

I understand what you are saying, but lets play Epidemiology here. We observe that the feet of many long-distance thru-hikers grow in both length and width. Too many observations to dismiss. What is going on?

> If my first metatarsal bone is 10 cm long, and it lengthens by 3%, then it has
> lengthened by 3 mm. The other metatarsal bones in the long part of the foot have to
> accommodate that stretch, or grow proportionately, because they are all
> biomechanically linked.
Of course. Perfectly obvious. But why would just one metatarsal bone grow, and not the others? That does not make sense to me. Instead I suggest that if the conditions are right to cause one bone to grow 3%, then I would expect all the associated bones to grow by similar amounts.

As for precise tolerances – I don't think the body has too many of those. Consider the adult waistline!
> When those tolerances are exceeded, malfunction, pain, swelling, etc occur.
Yeah, well, long thru-hikes have their share of that too. Don't dismiss that observation either.

Back to my bottom line. We observe foot growth after extreme conditions. How does it happen?

Cheers

[Jennifer Mitol]

This is almost worse than having an discussion about Obamacare.

Almost.

[Anonymous]

He certainly is a very um… persistent/determined fellow, isn't he?

[M B]

Is it possible, particularly in young males in their early 20s, that hiking delays the calcification of the growth plates on the end of the bones?

[Diane Pinkers]

Roger, i agree very much that we don't know what is happening during foot swelling, I just reject your notion of bone growth being part of it. It contravenes physiology,and ignores a plethora of other reasons why feet could swell. It is an area that no one has studied, and you can theorize all you want, but without data we are all just blowing smoke. To make a proper theory, it helps if you review current science on anatomy and physiology, then propose a rational mechanism, then run an experiment that tests your theory. Otherwise, you can theorize that moonshine and fairy dust make your feet swell up as you dance down the trail. In this instance, Jennifer has expert knowledge that you are ignoring.

Soft tissue has different tolerances than rigid structures like bone and cartilage. Abdominal waistlines can stretch far more. However, given the long term effects on the organsim, I submit to you that tolerances are being overridden. The body has great capacity to compensate, but over time, diabetes, heart disease, gout, etc, are all evidence of organism break-down. We have a sorry tendency to be short-sighted, and think if the problem isn't breaking things immediately, we can forget about it. The fact that the damage takes years to manifest in final dysfunction doesn't change the fact that the mechanism is broken.

Scientific paradigms do change, but if you think about it, most of the really world-shattering changes happened before the elaboration of the scientific method. Proposing a hypothesis, then making observations or experimenting to test the theory has really advanced the knowledge of the world far more than any other method. The other time that things turn over is when scientists relentlessly ignore conflicting data because it contravenes their pet theory. Once the data has mounted against them to the extent that they can't ignore it any longer, that theory gets crushed, and science moves on. But then, that's not really science, is it? Science is about asking questions, not knowing answers, but you can't ask the right questions without a firm foundation of knowledge. Skepticism is good, otherwise you don't always observe what is in front of your face, but you can't doubt everything, or no one will get anywhere.

MB, in young males their feet may still be growing slightly in bulk, but the growth plates by and large close between 14-16 years of age, when puberty happens. There will always be individuals on the ends of the bell curve that close later, but they are the exception. And, that doesn't explain how come my feet, attached to a 44 year old overweight woman, have gone from size 7.5 to 10.5 in the last 4 years, all due to hiking. It is largely in width, however, not length–the 10.5 shoes have too much toe at the end, but I had to go up to accomodate the width.

[Charley White]

>I understand what you are saying, but lets play Epidemiology here. We observe that the >feet of many long-distance thru-hikers grow in both length and width. Too many >observations to dismiss. What is going on?

Begging the Question, in it's formal meaning in logic (not its common "raising the question').

Even allowing the plural "we", that numerous people have collected reports of many hikers saying their feet grew longer, that is empirical evidence of only: that many hikers SAID their feet grew longer. Based on that, the first hypotheses I would test are: people are poor reporters of what actually happened with themselves (as opposed to what they feel happened); and they are the most least reliable when talking about their feet. ;)

But I do acknowledge a rigid outlook here. I'm convinced by evidence showing eyewitness accounts are the least reliable of all; "base pack weight" is a qualitative statement while "from skin out" is empirical; and that the scale, ruler, X-ray, and MRI don't lie.

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