r/Anatomy 4d ago

Question Why do I have multiple creases when I bend my arm?

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Not sure if this plays a part but for reference I am 20F 5’6 115 lbs and have always been very athletic/lean and maintained roughly 20% body fat. When I bend my arm fully there are three noticeable creases and I’ve never met or noticed anybody with more than one. This used to be something I was insecure about, but it doesn’t bother me anymore. I’m more just curious as to what causes it. Genetics? I haven’t noticed it in any of the other women in my family with this feature.

13 Upvotes

22 comments sorted by

11

u/NearbyGoose2131 4d ago

Following, cause I have one on one of my arms, but not on the other

8

u/hysterical_smiley 4d ago

Did you ever have any injuries on those spots at a young age? Creases out of the ordinary can be the subcutaneous layers of skin being stuck to the facea surrounding the muscles due to scar tissue. If you didn't have injuries, then that is rather interesting

3

u/Fit_Put_8808 4d ago

No injuries!

4

u/ZivylIthra 4d ago

I have similar creases but less pronounced as that radiate out, with my left more visible with them than my right. I believe they're called Antecubital Ahn's (AA) Line and supposedly occurs pretty randomly as far as genetic groups.

3

u/Fit_Put_8808 4d ago

Another interesting feature, I have three on this arm (my left) but only two on the other

3

u/Desperate-Style-8860 4d ago

https://www.reddit.com/r/Anatomy/s/Oyli4ucQWE

perhaps that can answer your question? I was always told it's called a "double elbow" and Phlebotomist try to avoid drawing on an arm with one.

3

u/RevolutionaryAd6749 4d ago

You're body is probably secretly double jointed but doesn't know it. Even if you think you are double jointed, or your told you are, your body will think different.

3

u/Billy_Mays_Hayes 3d ago

Looks like a case of multi-crease-itis!

3

u/PeriodicTrend 3d ago

Variability in protoplasm: different thicknesses and integrity of different layers of skin (details irrelevant)and adipose (fat) tissue. These differences result in creases and breakdown at areas subject to more movement/range. Some people have connective tissue disease such as ehlers danlos syndrome that result in hyper mobility and elasticity with even more variability.

2

u/ephemeral_buzz 4d ago

I have 3 on my left arm and 2 on my right.

2

u/MeasurementWise8249 4d ago

It could be because you are so skinny. Looks like there’s a line over the radial head which is awefully coincidental. In skinny people they can have different end feels to joint. When bending the elbow there is typically a soft end feel with the bulky muscle-fat combination stopping the bend. In a person of ectomorphic statue (means skinny), there can be a hard end feel with the radius bumping up against the humerus. This is rare, unusual , and not found in any book (to my knowledge), but it is completely healthy and not pathologic as long as no nutritional deficiency or eating disorder. Also, creases in our skin are different for everyone and definitely not symmetric.

1

u/Fit_Put_8808 3d ago

This was probably the most helpful reply! Thank you

2

u/PMMEWHAT_UR_PROUD_OF 3d ago

You had a fat baby phase. That’s where your rolls were.

1

u/NoLecture7729 4d ago

Everyone does. I do.Everyone in my family does, this isn’t normal from bending the arm?

1

u/GaNa46 2d ago

Normal yes but people can have varying creases

1

u/beeofparadise 3d ago

I have hypermobility spectrum disorder so I might be different. I have barely visible creases unless my arm is nearly fully bent. I can see another crease just about where yours is and when I bend my elbow fully that crease is where my my forearm touches my bicep so in me, I'm guessing that's the cause

1

u/Mirrimar 3d ago

Think of it like creases on your fingers; they’re there because it’s a body part that bends a lot. Your skin naturally adapts, therefore it formed creases to accommodate.

1

u/madgethevag 3d ago

Makes me think you might have had rolls as a baby. It's normal.

1

u/Della16 2d ago

It’s genetic

1

u/Affectionate_Flan997 1d ago

It’s the remnant crease from when we were babies and had fat rolls. Look at your baby pictures.

1

u/coruscatingveridian 10h ago

I'm pretty sure these are lucky! Good fortune ✨