Toe grip and foot weakness

[Gerrard Farrell]

If you stand in single leg stance, barefoot, and put pressure onto your toes, they will remain straight if the intrinsic foot muscles are strong enough. If they are not strong enough the lesser toes will collapse into a hammer toe configuration for as long as the pressure is exerted .

Since time immemorial this collapse has been viewed as toe gripping, it's not, it's toe failure and this distinction, which as far as I can make out I am the first to point out, is very important .( I am aware that that last sentence sounds utterly extraordinary)

A subject might be encouraged to balance on one foot and then watch their toes. If they stay straight fine, but what if they now press their COM forwards to put the toes under more pressure? Still straight, good, but if they buckle you might want to consider strengthening to restore function.( Balance challenges like the one described should be done with a means of support ,such as a chair ,to hand to avoid falls. Also ,it may be best to avoid doing this little experiment unless pts are otherwise healthy and have never had surgery to their feet esp any form of fixation
)

[Gerrard Farrell]

For those who are interested, here is a link to my twitter page- https://twitter.com/farrellgerrard . If you look at the second post ( April 24, 2022 ) you can see a short video of a man's foot as he tries to stand on one foot . The lesser toes of the subjects foot can be seen to go in and out of a hammer toe configuration or in and out of a collapsed position, same thing .

From experience, if you take a subject who's toes collapse under load and strengthen them, they then remain straight under load. If you see a pt and their toes collapse under load then IMO you really should be trying to do something to correct this.

Mickle et la demonstrated that the toe flexor strength of older subjects can be improved and brought up to the same levels as they would have had in their younger days.

An open access paper has just been published on the very active role that the intrinsic foot muscles play during stance and it is worth noting that most falls in the elderly occur during simple weight shifting .

https://doi.org/10.1155/2022/7708077

Show citation Contributions of Intrinsic and Extrinsic Foot Muscles during Functional Standing Postures

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Sarah T. Ridge,¹ K. Michael Rowley,^2,3 Toshiyuki Kurihara,⁴ Matthew McClung,¹ Jiaxi Tang,³ Steven Reischl,⁵ and Kornelia Kulig³

[Edmund Cramp]

I wonder if Dupuytren's contracture might be a factor? It's normally seen in subjects hands and affects their fingers, but not thumbs. So if it were to be a minor factor in the foot then I wonder if it might be related - I'm just guessing, based on the effect it has on both my hands. Thanks, it's an interesting post.

[Gerrard Farrell]

Hi Edmund

Funnily enough I was just discussing Dupuytren's contracture with a fellow masters athlete who specializes in the shot put but who is now having problems holding the shot. Fortunately, at 80 years of age, the weight of the men's shot is down to 3kg I think, so he still manages ( Actually, I think he set a UK age group record a few weeks ago. )

With regard to the video originally placed on Facebook by Tim Trevail @Trevail which shows one of his patients trying to balance on one foot and which was later retweeted by me, I don't think that the collapse seen as the toes are put under load is connected to Dupuytren's but rather to intrinsic foot muscle weakness since the toes can be seen to move in and out of the collapsed position as they are loaded then unloaded as the subject struggles for balance .

I will put a video of my own onto youtube which demonstrates toe collapse under load as soon as I can find a willing volunteer. My own feet are pretty strong and don't collapse and I have found that the feet of habitual hillwalkers are also strong and non collapsing even in the 50-60 age group.

The feet of relatively inactive women over 40 do generally collapse under load but non of these subjects will agree to a video ,even just from the knees down!

[Edmund Cramp]

I've been reading "The Story of the Human Body: Evolution, Health and Disease" and other books by Dan Lieberman - they are all just fascinating. Thinking about all this research into the way we have become our current bodies, I wonder if seeing Dupuytren's contracture as we get older might not be just a slight return to our ancestors genetics physiology. This is just a curiously crazy idea that I've not seen anywhere but reading about our evolution and watching my exercise to stay old and healthy is so much fun after years of working with people performing gait analysis.
Starting to walk forced our toes to become straight originally, but our ancestors needed bending toes to stay in their trees so I wonder if the evolution was not 100% efficient. Could that result in what you are seeing?

[Gerrard Farrell]

I don't believe it is what we see when loaded toes collapse, Edmund .

As we evolved our big toes became adducted and our feet became "organs" of balance and propulsion rather than grasping appendages. Our hands, with their opposable thumb, very much retain their grasping, holding function.

However, even when we invert and walk on our hands they do not grip the ground but instead the fingers remain generally straight and fanned out for better balance and weight distribution.

The picture shows two youngsters doing hand stands on the sand .Their fingers are spread out for balance but can you imagine what would happen if they dug their fingers into the sand for "better balance ". They would have less area to balance on and would likely fall over, with fists full of sand .

The idea that the toes curl on flat surfaces to give better grip is almost universal and, IMO, and at the same time, preposterous. Research done with toe grip dynamometers (the type were the toes grip over a bar and try to pull it back towards the heel) in the belief that this measures an actual everyday physiological function is, again IMO, extraordinarily ill-informed.

From experience rather than guesswork, I can tell you that if you take toes that collapse under load and strengthen them by flexing the toes around the MTPJ ,against resistance, then the toes will no longer collapse . This is not something the subjects are even aware of till you point it out.

IMO feet which have toes that collapse under load clearly need strengthened . That is to say toes that are straight until loaded but are otherwise healthy.

I believe my thinking here is disruptive since it suggests a simple functional test for foot weakness that necessitates strengthening protocols be implemented by clinicians who might not be in a position to get paid for supervising these .

Going back to the picture on the beach, if when you walk on your hands on a soft substrate your fingers remain straight and spread out for balance, why on earth would your toes "curl up for grip " when you walk on your feet ?

[Gerrard Farrell]

Closely related to the above -

"10-second balance test may predict longevity - NBC Newshttps://www.nbcnews.com › health › health-news › 10-s...
4 days ago — People who failed a 10-second balance test of standing on one foot were nearly twice as likely to die in the next 10 years, according to a ..."

and

"Participants in the supervised, progressive resistance training group significantly increased their toe strength (up to 36%; P<0.02), whereas there was no change in toe strength in either the home-based or control groups. This increased toe strength was accompanied by a significant improvement in perceived general foot health and single-leg balance time compared to the other groups (P<0.05)."

Note; home base group included things like towel curls ;these exercises don't work !

Mickle et al 2016

[Edmund Cramp]

While I think that the balance test is potentially helpful, it makes me think about the early days of gait analysis when the clinical users recorded not only the heel-strike and toe-off timing of their subject's gait, but also recorded the 1st and 5th metatarsal foot contact timings to get measurements of the stability of the subject in their gait stance phase as they walked.

[Gerrard Farrell]

Recent research does make a person think though Edmund. Subjects taking part in various gait studies and who are presented as fit, health, young adults will, in some regards, have feet only half as strong as they should be due to the very considerable effects of shoes on foot morphology.

I am not sure minimal shoes are a good idea in all circumstances but you can't go far wrong strengthening weak feet, which is just about everybody's, runners included.