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Intuitively we are the only mammal walking upright so at the middle hinge, there must be some very strong muscle keeping us from folding over?
by thefz 2y ago
Intuitively we are the only mammal walking upright so at the middle hinge, there must be some very strong muscle keeping us from folding over?
- bilsbie 2y agoHow do birds manage?
- Jensson 2y agoBirds are small, that means you don't need much muscle.
- dmurray 2y agoOstriches weigh about the same as adult humans. Birds do have a rump (the part of them behind the legs) which perhaps serves a similar function to human buttocks.
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- illwrks 2y agoRandom uninformed idea… this is surely wrong but… birds ‘knee’ joints are the opposite of humans, have their ‘butt’ muscles have evolved alongside their wing/breast muscles?
- rusticpenn 2y agoBirds knee joints are human ankle joints.
- illwrks 2y agoI’ve learned something new today!!
- afiori 2y agoBird knees are in the same direction as all other knees, the articulation you are thinking about is the ankle https://en.m.wikipedia.org/wiki/Bird_feet_and_legs https://en.m.wikipedia.org/wiki/Bird_feet_and_legs In a lot of mammals too the knee is "hidden" https://duckduckgo.com/?q=horse+hind+legs+anatomy&t=fpas&iax=images&ia=images&iai=https%3A%2F%2Fhorsesidevetguide.com%2Fwp-content%2Fuploads%2F2014%2F11%2FFINAL-QR-Hind-Limb.jpg https://duckduckgo.com/?q=horse+hind+legs+anatomy&t=fpas&iax...
- illwrks 2y agoHa!! Amazing, I should watch more nature documentaries!!
- loloquwowndueo 2y agoBirds are not mammals.
- thefz 2y agoAre birds mammals?
- readyplayernull 2y agoPlato is that thou?
- pjot 2y agoMade me spit my coffee out
- bluGill 2y agoBirds are generaly balanced with their legs in the middle of thier body. Those with legs to the back don't walk as well (but that leg position gives other advantages that the bird might need)
- icegreentea2 2y agoBirds are bipedal, but their trunks/spine are closer to perpendicular to their legs (while ours are parallel and stacked). Birds also have a non trivial amount of mass hanging down from their trunk between their legs, and their hips tend to extend significantly past their legs. So while birds actually need significant posterior chain muscles to keep the femur extended, those muscles get to attach to an extended hip and so form more of a triangular/trapezoid shape compared to human butts. If you ever noticed that chicken thighs from the store seem a little triangular, and the bones are 'off center', then the the larger triangularish half of the chicken thigh is the chicken analogy to the glut complex. EDIT: I think people would generally define the depth of the human intergluteal cleft ("butt crack") as one of the defining features of the human butt. In that context, I think humans have this feature at least partly because the human hip is... suboptimal in many ways. When considering the gluts as a hip/femur extensor, you have some pretty bad leverage, and so you're already biased towards having a very bulgey muscle there. As opposed to something like our hamstrings which has a much better leverage scenario, and so you see much less of an obvious bulge. By analogy, since birds tend to have an extended hip to attach to, their glut max analogs are no where as bulgey.
- KineticLensman 2y agoWhen a bird is perching or walking on the ground, it is almost never standing with its legs under the entirety of its body. A bird is like a rectangular box whose long axis is parallel to the ground with two sticks just slightly aft. In contrast, a standing human has a rectangular torso whose long axis is at 90 degrees to the ground with the legs coming out of one end. To see this, do an image search for an Ostrich, which shows the 'box' effect perfectly. Smaller birds have a body box that is often at more of an angle to the ground, and with legs that are tiny compared with a human's. The bird's hips are near the back of the box but there are usually bones behind them, which is where the tail is mounted. The equivalent of the femur is tilted forward and short compared with a human's, and a bird's sternum may actually be between and below the equivalent of our knees. Very different anatomy.
- MrMcCall 2y agoThat, and running away from lions and hyenas and those worst killers of Africa: the hippopotamuses. Speaking of butts, as avid watchers of nature documentaries, the all-time funniest thing we saw in one was a hippo standing with its rear towards the camera in thigh-deep water, pooping while furiously swishing its tail back and forth just spraying it as far and wide as it could, for 5-10 seconds IIRC. And, yeah, just search YT for "hippo spraying poop with tail", if you want to see that sh_t.
- noman-land 2y agoI had the misfortune of seeing this hippo behavior in real life at a zoo and the reactions it got from the crowd of parents and kids was one of the funniest things I've ever seen.
- 082349872349872 2y agoSpeaking of butts and massivesci, when I'm searching YT, I prefer both kinds of callipygian: https://www.youtube.com/watch?v=gwti7-cEHh8#t=39s https://www.youtube.com/watch?v=gwti7-cEHh8#t=39s For manure spreading, I prefer automation, in particular "New Idea"s: https://www.youtube.com/watch?v=oTuK2Xm3q5I#t=18s https://www.youtube.com/watch?v=oTuK2Xm3q5I#t=18s
- MrMcCall 2y agoI like what Bob Newhart said about country music, and thank you very little for the new word :-)
- dist-epoch 2y agoI don't think you can run away from a lion or hyena.
- MrMcCall 2y agoWell, I'm not gonna just stand there! Besides, I only have to outrun you.
- cultofmetatron 2y ago> there must be some very strong muscle keeping us from folding over? the gluteas maximus IS the biggest muscle in the human body
- api 2y agoIt’s more for running and carrying. Humans are at least in some instances exhaustion hunters. We will chase prey over long distances. The way we run makes extensive use of that muscle to push us forward. We also need to carry stuff over long distances: our helpless babies, food, and later in our evolution packs full of tools and basically camping gear. Lastly, we are the only species with Sir Mixalot.
- dghughes 2y agoKangaroos do too. Technically they are mammals Class: Mammalia Infraclass: Marsupialia. Then again we walk not bounce.
- mystified5016 2y agoI'm not sure that really counts as kangaroos use their tails as a third leg for balance.
- dghughes 2y agoSo do I.