I was born with feet in the 1st percentile of the population and they stayed that way even despite getting taller. Now every shoe shopping experience is awkward af.

    • NocturnalMorning@lemmy.world
      link
      fedilink
      English
      arrow-up
      61
      arrow-down
      4
      ·
      3 days ago

      Uh, no, that’s actually the opposite of how that works. Pressure is force per area, and torque is the cross product of force and length (at right angles). The smaller the area, the higher the pressure. The smaller the foot, in this case, the harder the muscles have to work to create the same torque (or moment). #ThanksForAttendingMyPhysics101TEDTalk

      • deranger@sh.itjust.works
        link
        fedilink
        English
        arrow-up
        27
        arrow-down
        2
        ·
        edit-2
        3 days ago

        The smaller the foot, in this case, the harder the muscles have to work to create the same torque (or moment).

        That’s backwards, a shorter lever arm requires less force. If you had a 10 foot long foot, you’d have to have insanely strong calf muscles to stand on your tip toes, because how far the load is from the fulcrum.

        torque is the cross product of force and length

        Correct. The force at the end of the lever is your body weight. A longer foot thus exerts more torque on your ankle and requires more calf muscle to move. Longer arms don’t make chest flyes easier, they make them harder.

        • LustyArgonian@lemmy.world
          link
          fedilink
          English
          arrow-up
          5
          ·
          edit-2
          3 days ago

          This isn’t totally true (about longer limbs=harder to exercise), because it doesnt take into account how myosin works on a longer muscle/surface area, along with how electrical differences between limbs and the torso help with electrical flow due to potential energy.

          Look at a thoroughbred (fastest over medium distance), an Arabian (best for endurance), a quarter horse (fastest in burst over short distance) versus a donkey (stronger pound for pound than a horse but not faster), vs a mule (stronger than horse, faster than donkey). Keep in mind there’s different types of muscle development, eg burst vs long distance. Look at their legs. They are walking on (1) finger, look at where their ankle is. Their feet, like many animals, are angled completely differently than humans. Elephants have a similar foot to humans in that their sole contacts the ground, but obviously their feet don’t extend like ours (and they have bigger muscles). So it is interesting but I think theres more to it

          • deranger@sh.itjust.works
            link
            fedilink
            English
            arrow-up
            7
            ·
            edit-2
            3 days ago

            It’s totally true from a physics standpoint. A longer lever arm between the load and fulcrum requires more force to move the same weight, all else being equal. Edit: thinking on this more, I think a type 3 lever is more applicable to my chest flye example, but the same concept applies; as you lengthen the load arm relative to the effort arm, more input force is required to move a given load.

            “Harder to exercise” is poorly defined, especially when you go on to discuss endurance, speed, and force, all of which are very different terms.

            I totally get what you’re saying, but I specifically narrowed it down to force for a reason. My shorter friends kick my ass in lifting due to the mechanical advantage their shorter limbs have, but I smoke them in a distance run because my longer limbs allow me to traverse a greater distance in a single step. This is complicated though because larger lungs are a factor here too.

            • LustyArgonian@lemmy.world
              link
              fedilink
              English
              arrow-up
              1
              ·
              22 hours ago

              “All else being equal,” it’s not equal though, that’s what I’m saying. Our legs have electrical and muscular aids in them which make them unlike a lever completely.

              You shortened it down to simplify a complex topic. I’m pointing out it’s not that simple and it’s okay to learn more. As we age we should keep up with learning dense subjects to keep up our neuroplastocity, and it’s a social virtue. Right now I’ve been learning about electrobiochemistry for instance. You can just download textbooks. Please stop committing to simplicity when reality is complex.

              Physiology wouldn’t encapsulate a huge subject and multiple specialty fields (physiologists, occupational therapists, physical therapists, medical technologists, physical educators, surgeons, biomedical engineers) if it was simple physics. We wouldn’t need all the other muscles and junk if it was all simple physics. It’s not. It’s a highly complicated series of biochemical, magnetic, electrical, energetic, and physical properties that work against and with each other

      • Jerkface (any/all)@lemmy.ca
        link
        fedilink
        English
        arrow-up
        9
        arrow-down
        2
        ·
        edit-2
        3 days ago

        The foot bears more than 100% of your weight because it is cantilevered. The greater the cantilever, the greater the multiplier to the weight.

        You’re arguing that a small foot has a small contact patch. But we need to be able to shift all our weight to our toes, and that contact patch is more a function of the width of your foot, not the length.

    • deranger@sh.itjust.works
      link
      fedilink
      English
      arrow-up
      13
      ·
      3 days ago

      That would be relevant to the calf muscles, but the lower surface area of the feet means higher pressure in terms of psi or pascals.

      • Leggomylego@lemmings.worldOP
        link
        fedilink
        English
        arrow-up
        20
        ·
        3 days ago

        Yes I can confirm that there’s more pressure on my feet if my wearing out kids shoes every 6 months is anything to go by. They are not designed for a man of my height and weight!

        • LustyArgonian@lemmy.world
          link
          fedilink
          English
          arrow-up
          5
          ·
          3 days ago

          Have you ever had custom shoes made? Or checked what adult little people wear? They may have some suggestions