Show Notes
A follow up Q&A to the foot health deep dive with Dr. Ronald Talis earlier in the week. Dr. Ravi Kumar picks five of the best listener questions and does a mini deep dive on each, tying together the key themes from the full conversation and filling in a few of the practical and biological gaps.
If you listened to the foot health conversation with Dr. Ronald Talis earlier in the week and walked away with more questions, this is the follow up. Dr. Kumar works through whether feet weakened by a lifetime in shoes can actually be rebuilt, whether the overpronation diagnosis and the motion control shoe industry are backed by real evidence, why two years of stretching and anti-inflammatories may not be touching your plantar fasciitis, whether a child’s flat feet truly need arch supports, and how seriously to take the idea that the foot is the canary in the coal mine for vascular disease. He closes with a bonus home remedy: soaking your feet in warm black tea for excessive sweating, and the real biology behind why it works.
In this episode, you will discover:
- Whether weak feet can be rebuilt: A 2019 randomized study of 57 runners found that eight weeks of either targeted foot strengthening five days a week, or simply walking around in minimalist shoes during daily life, produced equal gains in foot muscle size and strength. The Foot Core System framework, laid out in a foundational 2015 British Journal of Sports Medicine paper, treats the small intrinsic foot muscles like the deep core of your spine: local stabilizers that atrophy when unloaded but respond to training like any other muscle. Start barefoot at home, do single leg balance on a pillow, toe scrunches, and towel pickups, then transition slowly to a wider toe box, low drop shoe
- Whether the overpronation diagnosis is real: Pronation is a normal, necessary part of the gait cycle, not a defect. A prospective 2014 British Journal of Sports Medicine study of 927 novice runners in neutral shoes found pronation was not associated with higher injury risk, and a large randomized American Journal of Sports Medicine trial found matching shoe type to foot type did not reduce injuries. A 2021 secondary analysis did find motion control shoes helped recreational runners who already overpronate, so a subset benefits, but the blanket claim that everyone who pronates needs a $150 motion control shoe is not supported
- Why your plantar fasciitis is not improving: A 2003 study of 50 chronic cases found no inflammation in the tissue at all, only degeneration: microscopic fiber damage, scarring, and fragmentation. The condition is more accurately called plantar fasciosis, which changes the entire treatment logic. Anti-inflammatories and repeated steroid injections target inflammation that is not there, and the paper raised real concerns about steroids weakening the fascia. The actual fix is the slow work of remodeling tissue: calf and Achilles stretching, plantar fascia stretching, eccentric loading, and rebuilding the intrinsic foot muscles
- Whether a child’s flat feet need arch supports: Dr. Talis calls flat feet “a type of normal.” A 1993 Archives of Family Medicine study of 246 army trainees found the expected strong link between flat feet and injury simply was not there. A rigid, painful flat foot in a child, or a sudden adult arch collapse that may signal posterior tibial tendon dysfunction, deserves attention. But a pain free kid running around like every other kid probably does not need orthotics. Time on uneven and natural surfaces beats arch supports for an asymptomatic child
- Why the foot is the canary in the coal mine for vascular disease: The blood vessels in your feet are small and as far from your heart as anything gets, so failing circulation often shows up there first. Cold feet, hair loss on the toes, dusky color, slow healing cuts, and leg cramps when walking that resolve with rest can be early signs of peripheral artery disease. The screening test, the ankle brachial index (ABI), is simple and cheap: ankle blood pressure divided by arm blood pressure, with a ratio under 0.9 considered diagnostic. Pay attention to your feet, do not smoke, control your blood sugar, and keep moving
- Bonus, black tea for sweaty feet: Dr. Talis recommends soaking your feet in warm brewed black tea once or twice a day for about fifteen minutes to treat hyperhidrosis, the technical term for excessive foot sweating. The tannic acid in black tea causes mild contraction of the sweat glands and physically reduces sweat output. It takes a couple of weeks of consistent use, but it is cheap, safe, and a legitimate home remedy worth trying before powders and antifungals
Key Takeaways
- Weak feet from a lifetime in shoes are not permanent. The intrinsic foot muscles respond to loading, and simply switching to minimalist shoes for daily life can rebuild strength as well as dedicated exercises. Transition slowly so your feet have time to adapt
- Pronation is normal, not a disease. Try shoes on, run in them, pick the pair that feels best, and let your body’s own biofeedback guide you rather than a sales pitch. Only a minority of established overpronators may benefit from motion control shoes
- Chronic plantar fasciitis is usually degeneration, not inflammation, so it is better called plantar fasciosis. Stretching, eccentric loading, and rebuilding the small foot muscles address the root cause; anti-inflammatories only quiet an acute flare
- A child’s flat feet are often just a normal variant. With no pain and no gait problem, time on uneven and natural surfaces usually beats arch supports. Reserve concern for painful, rigid feet or a sudden adult arch collapse
- Take foot symptoms seriously as early warning signs of vascular disease. Cold feet, thinning toe hair, color changes, and slow healing cuts warrant an ankle brachial index test and attention to the basics: do not smoke, control blood sugar, move your body
- For sweaty feet, a warm black tea soak is a cheap, science backed first step, thanks to the tannic acid that tightens the sweat glands
If you have not yet listened to this week’s main episode, The Heart-Foot Connection: Why Your Feet Are Warning You About Heart Disease with Dr. Ronald Talis, start there. This Q&A builds directly on that conversation.
Transcript
Dr. Ravi Kumar: Hey, everybody. Welcome back to The Dr Kumar Discovery. Earlier in the week, I interviewed Dr. Ron Talis on foot health, and I got a bunch of really good questions afterward. So I picked five of the best ones to do a mini episode on. I think this will tie together most of what we covered earlier in the week. So let’s get started.
Dr. Ravi Kumar: Okay. First question. I’ve worn shoes my whole life, and my feet feel weak. Is the damage permanent, or can I actually get the muscle back?
Dr. Ravi Kumar: Okay. So there’s good news here, and that is that you can absolutely get it back. And the research on this is encouraging. A study published in 2019 took 57 runners, and randomized them into three groups. One group did targeted foot strengthening exercises five days a week. One group just walked around with minimalist shoes for their daily activities, and one was a control group. After eight weeks, both intervention groups gained foot muscle size and strength. What I thought was really neat about this study is that the minimalist shoe walkers gained just as much as the people doing dedicated exercise just by changing what they had on their feet during normal life. And this fits into a bigger framework called the Foot Core System, and this was laid out in a foundational paper in the British Journal of Sports Medicine in 2015. The idea is that the small intrinsic muscles in your foot function in the same way as the deep core muscles function in your spine. They’re the local stabilizers. They’re small, they’re routinely ignored, and they atrophy when you don’t load them. But they respond to training the same way that any other muscle does.
Dr. Ravi Kumar: So, where would you start on this one? Well, honestly, the simplest things work the best. Spend time barefoot at your home, try the single leg balance that Dr. Talis talked about, which is standing on one foot on a pillow for thirty seconds. And once that gets easy, do it with your eyes closed. Pick up a towel with your toes. Do toe scrunches while you’re watching TV. And if you wanna go further, transition to a wider toe box shoe with low or zero drop sole. You don’t have to go the full Vibram FiveFingers overnight, but a minimalist shoe right off the bat is going to strengthen your foot. Just take the transition slowly because your feet do need time to adapt. But the muscles are still there, and they’re waiting to work.
Dr. Ravi Kumar: Okay. Next question. The salesperson at the running store told me I overpronate and need motion control shoes. Is that actually based on anything?
Dr. Ravi Kumar: Okay. So this is a great question, because it gets into how marketing, dressed up as science, convinced the whole industry of consumers that something normal is actually a defect. First, pronation itself is not pathological. It’s a normal, necessary part of the gait cycle. Your foot has to pronate to absorb impact when it hits the ground, and then it has to supinate to launch you forward. If your foot didn’t pronate, you wouldn’t be able to walk on uneven ground without rolling an ankle. So the idea that pronation is something that should be stopped is wrong from the start. Second, the science on matching shoe type to foot type is much weaker than the running store would have you believe. A prospective study published in the British Journal of Sports Medicine in 2014 followed 927 novice runners wearing neutral shoes, and found that foot pronation was not associated with increased injury risk. And a large randomized trial published in the American Journal of Sports Medicine also showed that matching shoe type to foot type did not reduce injuries.
Dr. Ravi Kumar: But the picture isn’t fully black and white. There was a secondary analysis published in the Journal of Orthopedic and Sports Physical Therapy in 2021 that did find that motion control shoes reduce pronation related injuries in recreational runners who already overpronate. So there may be a subset of pronated runners who do benefit from this. But the blanket recommendation that everyone who pronates needs a $150 motion control shoe is not what the evidence supports. So what should you do? Well, I say just try shoes on, run in them, and then pick a pair that feels best. If something hurts, change it. And don’t let a sales pitch override your body’s own natural biofeedback. And also remember that in the end, you wanna use the muscles in your feet, not immobilize them.
Dr. Ravi Kumar: Okay. So next question. I’ve had plantar fasciitis for over two years, and I’ve tried stretching, ice, and anti-inflammatories. Nothing’s working. What am I missing?
Dr. Ravi Kumar: Okay. So this is a really common frustration, and the answer might be hiding in the name of the condition itself. A paper published in 2003 looked at tissue samples from fifty cases of chronic plantar fasciitis. What they found, or actually what they really didn’t find, was inflammation. There was no inflammation in those tissues. And this is something that Dr. Talis talked about in the podcast. In that study, not a single sample showed cellular signs of inflammation that the suffix itis in plantar fasciitis actually means. What they did find was degeneration of the plantar fascia. These were microscopic fiber damage, scarring, fragmentation. The authors proposed that the condition is more accurately called plantar fasciosis, not fasciitis. So it’s a degenerative problem, not an inflammatory one.
Dr. Ravi Kumar: So if the underlying tissue is degenerated rather than inflamed, that changes the whole treatment logic. Repeated steroid injections, which work for inflammation, might be the wrong tool for degeneration. The paper actually raised real concerns about steroid injections weakening the fascia and increasing rupture risk. And that wasn’t Dr. Talis’ experience, and he talked about it in the podcast. He actually thought for the right patient, a deep steroid injection could give them significant relief. So what works? Well, anti-inflammatories will reduce pain in an acute flare, but they don’t fix the underlying issue. What actually fixes it is the slow boring work of remodeling fascia. That’s calf and Achilles stretching, plantar fascia stretching against a wall, eccentric loading, and restoring strength in the intrinsic foot muscles we talked about in the first question. Dr. Talis also pointed out something that I thought was really insightful. A lot of what gets diagnosed as plantar fasciitis is actually just fatigue in those small foot muscles, and there’s no diagnostic code for your feet are weak. So it gets billed as plantar fasciitis by default. But either way, the treatment for both is the same. You need to rebuild your feet from the inside out with strengthening and stretching.
Dr. Ravi Kumar: Okay. Next question. My pediatrician said my kid has flat feet, and we should put them in arch supports. Is that really necessary?
Dr. Ravi Kumar: Okay. So this is one of my favorite parts of the conversation because Dr. Talis explicitly pushed back on the idea that flat feet are inherently pathological. He called it a type of normal, which I totally loved. And the data backs him up on this one too. A classic paper in the Archives of Family Medicine in 1993 looked at 246 army trainees, and tracked the relationship between foot type and exercise related injury. And the strong predictive relationship with flat feet and injury that most people would expect just wasn’t there. So the foot type that everyone worries about, flat feet, might actually be safer in some context.
Dr. Ravi Kumar: But the picture is still nuanced. A rigidly flat foot in a child who can’t keep up with their peers because they’re in pain, that does need attention. An adult whose arch suddenly collapses in their forties, that’s likely a posterior tibial tendon dysfunction, and worth seeing a podiatrist about. But the kid whose feet are just flat, and they’re running around like every other kid, no pain, no obvious gait issues, probably doesn’t need orthotics. The bigger question is whether putting a flat foot in an arch support actually changes the long term trajectory of the foot. The evidence for that is weaker than most parents are led to believe. Arch supports can relieve symptoms when symptoms exist, but they’re not a vaccine against future foot problems. If your kid has no symptoms, the better intervention is probably the one Dr. Talis kept coming back to. And that was time spent on uneven surfaces, time barefoot on the grass or sand, or some natural surface, and using feet the way feet are actually designed to be used.
Dr. Ravi Kumar: Okay. Next question. Dr. Talis said the foot is the canary in the coal mine for vascular disease. How seriously should I take that?
Dr. Ravi Kumar: Okay. Take it very seriously. This is one of the most important things Dr. Talis said, and it ties the whole episode back to metabolic health in a way that I want to make sure that everyone gets. The blood vessels in your feet are small, and they’re as far from your heart as anything can be. So if your circulation is starting to fail, your feet are actually where it shows first. Cold feet, hair loss on your toes, dusky color, slow healing cuts, leg cramps when you walk that go away when you rest. These can be the earliest signs of peripheral artery disease that shows up first in the foot. So the screening test on this is simple and cheap. It’s called ankle brachial index, or ABI. You measure the blood pressure in your ankle and divide it by the blood pressure in your arm. A ratio under 0.9 is considered diagnostic for peripheral artery disease.
Dr. Ravi Kumar: So what should you do with this information? Well, I’d say, first, just pay attention to your feet. If they’re getting cold, if the hair is thinning on your toes, if your skin color is changing, if cuts aren’t healing the way they used to, don’t just shrug it off. Ask for that ABI, and work on things that drive vascular health overall. So that’s don’t smoke, control your blood sugar, move your body. So I’ve done full episodes on metabolic health, and they pair really well with this topic that we’re talking about right now. And if you want to go deeper, you should definitely go back and listen to them. But let’s just say this for now. The foot may be whispering warnings to you. All you have to do is listen to it and look at it.
Dr. Ravi Kumar: Okay. So those are all the questions, but there was one bonus topic that I wanted to talk about a little more because I thought it was really interesting. Dr. Talis recommended soaking your feet in warm brewed black tea once or twice a day for about fifteen minutes at a time as a treatment for hyperhidrosis, which is the technical term for excessive sweating of the feet. And the mechanism here is real and science backed. Black tea contains tannic acid, which is the same compound that gives tea that astringent taste if you drink it just plain black without milk in it. Tannic acid also causes mild contraction of your sweat glands, which physically reduces sweat output. So if you start doing this, it’ll take a couple weeks of consistent use to really see the effects, but it’s cheap, it’s safe, and it’s the kind of thing your grandma might have known about that turns out to have a legitimate biology behind it. So if you’re struggling with sweaty feet or athlete’s foot, before you go down the rabbit hole of antiperspirants and powders and antifungals, maybe try some black tea. Dry out your feet and see how you feel.
Dr. Ravi Kumar: Okay. That’s it for today. Big thanks to Dr. Ron Talis for coming on the show. If you haven’t listened to that full conversation I had with him, please go back and take a listen. It was a master class on the foot, and one that everyone should listen to. Your feet are the foundation of everything you do, and most of us have never given them five minutes of real attention. Okay. So cheers, and I’ll see you next week.