Background info

During physical examination

A physical examination may include checking vital signs, including temperature examination, Blood pressure, pulse, and respiratory rate. The healthcare provider uses the senses of sight, hearing, touch, and sometimes smell. [...] Although providers have varying approaches as to the sequence of body parts, a systematic examination generally starts at the head and finishes at the extremities. After the main organ systems have been investigated by inspection, palpation, percussion, and auscultation, specific tests may follow.


What tactile or and medical test-based differences would be noticeable to a trained medical professional on a person originating from a 3g world, given that this person is apparently normal height and weight?

Mind you that the tests and doctor are all on earth, in brief, a person from 3g world is transported to Earth and upon arrival said person is struck by motor vehicle and transported to hospital: what if anything would be noticeable to the attending?

  • $\begingroup$ What do you mean by tactile? That implies the sense of touch. I'm not a doctor, but I don't know of any doctors that perform 'tactile' diagnoses. That sounds like sexual harassment. $\endgroup$ – kingledion Jan 8 '18 at 2:46
  • $\begingroup$ Frankly I whould imagine that a doctor sense of touch might pick up differences in density of tissues.. $\endgroup$ – Randy Lowther Jan 8 '18 at 2:50
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    $\begingroup$ And think...checking glands...breast exams...abdominal palpitations ect.. $\endgroup$ – Randy Lowther Jan 8 '18 at 2:52
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    $\begingroup$ Tip for writing: serial usage of . is not a substitute for proper punctuation and/or conjunctions $\endgroup$ – L.Dutch - Reinstate Monica Jan 8 '18 at 3:40
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    $\begingroup$ @L.Dutch It's called ellipsis. It's currently misused chronically. I support your writing tip. It is a poor substitute. $\endgroup$ – a4android Jan 8 '18 at 7:24

I assume You mean (more or less):

Some aliens captured early humans, transported them unto a 3g planet and let them adapt to it (possibly with some help); a few hundred thousands year later one of some descendants comes back to Earth and has a stupid road accident and ends up in a hospital.

Any other sequence of events would produce a person that, even if apparently resembling a human wouln'd hold up any serious scrutiny (parallel evolution down to internal organ placement, vital parameters and blood composition is, at best, "unlikely").

In order to keep the body erect under continuous 3g acceleration muscle and bones need to be correspondingly "more efficient".

We already have several problems from our (relatively recent) erect posture; these range from easily failing L3-L4 spinal chord connection to hiatal hernia due to stomach weighing too much on esophagus. All these would be much worse under 3g stress.

In general this means all connective tissues would be much more resilient and, removed the stress, would appear "abnormally tonic".

At first glance our traveler would appear as a highly trained body-builder, possibly impossibly well trained and "tonic".

Other adaptations (sturdier spinal column) might be more difficult to hide.

  • $\begingroup$ Thank you for your response.Can I assume the dermis to more difficult to penetrate? i.e.hard to start I.V. lines on.Also whould vital signs be any different? Heart rate,Blood pressure ect.As my protagonist at this point is literally new to 1g environment, I am curious as to what a E.R attending whould be able to discern given both their innate skill and diagnostic tools? $\endgroup$ – Randy Lowther Jan 8 '18 at 15:40
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    $\begingroup$ As said all connective tissue would be stiffer (otherwise under 3g would sag a lot and even give away), but exact parameters are anyone guess. It is likely to have a rather high blood pressure (otherwise pumping it up to the brain would be difficult) and a more efficient drainage for venous system from the lower limbs (again: to counter gravity). If he didn't really have the time to adapt I think the most evident thing would be tendency to apply way too much force when trying to lift something (including oneself) or, to counter that, an excessive care in any movement (especially on stairs!). $\endgroup$ – ZioByte Jan 8 '18 at 19:47
  • $\begingroup$ Thanks.Trying to inject a sense of realism into a basically unrealistic scenario can be a little tasking.Thanks to one and all.This helped. $\endgroup$ – Randy Lowther Jan 8 '18 at 22:35

From the wikypage on human effects of weightelesness

The most common problem experienced by humans in the initial hours of weightlessness is known as space adaptation syndrome or SAS, commonly referred to as space sickness. Symptoms of SAS include nausea and vomiting, vertigo, headaches, lethargy, and overall malaise. The duration of space sickness varies, but in no case has it lasted for more than 72 hours, after which the body adjusts to the new environment.


The most significant adverse effects of long-term weightlessness are muscle atrophy and deterioration of the skeleton, or spaceflight osteopenia. Other significant effects include fluid redistribution (causing the "moon-face" appearance typical of pictures of astronauts in weightlessness), a slowing of the cardiovascular systems blood flow decreases in response to a lack of gravity, a decreased production of red blood cells, balance disorders, and a weakening of the immune system. Lesser symptoms include loss of body mass, nasal congestion, sleep disturbance, excess flatulence, and puffiness of the face. These effects begin to reverse quickly upon return to the Earth.

1g to 3g is rather different from free fall, but let's simplify that they are the same from the medical stand point. Your person is already past the 72 hours of adaptation, so we can exclude SAS.

What remains that can be noticed by physical examination?

  • "moon-face"
  • slowing of the cardiovascular systems blood flow
  • balance disorders
  • nasal congestion
  • excess flatulence
  • puffiness of the face

By other examination (DEXA) osteopenia can also be diagnosed.

  • $\begingroup$ You forgot bone density. $\endgroup$ – pojo-guy Jan 8 '18 at 4:03
  • $\begingroup$ @pojo-guy, as far as I know bone density cannot by determined by using senses. That's why I left it out. $\endgroup$ – L.Dutch - Reinstate Monica Jan 8 '18 at 4:09
  • $\begingroup$ I don't think this applies. Going from 1g to 0g is very different from going 3g -> 1g. I'm unsure if they have some data from astronauts when they were on the Moon; probably they stayed too shortly for significant analysis. $\endgroup$ – ZioByte Jan 8 '18 at 11:24
  • $\begingroup$ @ZioByte, permanence on the Moon was too short to have any significant insight on physiological variations. The only adequate info we have is on microgravity. So mine is something like an educated guess, lacking better info. $\endgroup$ – L.Dutch - Reinstate Monica Jan 8 '18 at 12:03
  • $\begingroup$ I agree with @pojo-guy, the OP asked for "What tactile or and medical test-based differences," which would include an X-Ray. $\endgroup$ – JBH Jan 8 '18 at 15:43

Under the presumption that the person has been born and living on the 3 g world there are some (probably a lot) weird features to your human.

If you are talking about a normal human, say male of 80 kg with a length of 1.9 m (BMI of 22.16). The person body would be equivalent to be weighing 240 kg. Although the human body can sustain this for short periods it is in the range of olympic weightlifting records. Normal movement would not be possible with this.

You would expect much thicker legs and bones (and bone density) and much stronger and muscular joint, this would however mean that he would be much heavier than normal and clearly oddly shaped. To keep a normal appearance and weigh the only way I think would be to have the load bearing bones to be square root of 3 times thicker (goes by area). So about 1.7 times thicker bones and less meat, presumably fat, to make up the weight difference.

This would be noticable even by just visual observation. Probably the whole human design won't work in 3g for longer periods of time. Maybe your body and muscles can be trained but I don't think our digestive track can function in such circumstances.


It would be less differences than you think.

3g is the equivalent of a person of 80kg gaining weight to 240kg. The 240kg guy is not impossibly strong.

  • $\begingroup$ Maybe definition but I would not call a guy of 240 kg normal. $\endgroup$ – D.J. Klomp Jan 8 '18 at 18:24
  • $\begingroup$ The olympic record for a 85 kg weightlifter is 180 kg "snatch" style and 217 kg "clean and jerk" style. And an olympic weightlifter holds that bar up for a few seconds, not for 24 hours a day. $\endgroup$ – AlexP Jan 8 '18 at 21:02

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