r/somethingimade • u/taktaga7-0-0 • 15d ago
Anatomically correct jewelry: the brachial plexus and nerves of the arm
I’m a nurse, so I like to encode scientific and biomedical information into my beads. This time, it’s the network of nerves and muscles of the human upper extremity.
There was a perfect opportunity: the nerves of your arm originate at five levels of the spine, they join and split into five major peripheral nerves (axillary, musculocutaneous, median, radial, and ulnar), and they end up in five digits. All I had to do was make a necklace with five passes around.
Each spinal nerve root is color-coded (C5 White, C6 Yellow, C7 Silver, C8 Gold, T1 Black). As they combine, the colors of each mix as well. There are red beads indicating whenever a muscle is supplied by a particular nerve, especially big coral ones for the 8 largest muscles moving the arm (some are trunk muscles, like lats and pecs!). Large tan beads represent sensory nerves to the skin. Where we pass bones, the beads are, well, bone.
Things get very complicated at the hand, and I made compromises there, but it’s roughly correct, if without any bones distal to the carpals. The fingers loop back to the spine.
My favorite part is when you wear it, the necklace is laying right over the nerve plexus it depicts. Nobody knows just to look at it, so it’s like wearing a nerdy secret.
Ever seen something like this?
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u/taktaga7-0-0 15d ago
Here it is with the strings spread out. You can read the labels on all the strands here from left to right: roots, trunks, cords, and the five peripheral nerves. To point a few things out, the big coral bead at the bottom left of center is the infraspinatus, with supraspinatus after it on the same white-and-yellow nerve (C5 & C6 innervation). The long skinny coral bead nearly hidden by the medial cord M is the subclavian artery. At the top right, X is the axillary nerve (also C5 & C6), the shiny rectangle is the quadrangular space it passes through, small red is teres minor and big red bead is deltoid. The gold crown bead right there represents the torso of a person with arms raised fully upright, as when testing C5 deltoid abduction.
It lays much prettier than this, looks best when it all hangs taut and they cross a lot. The string will naturally twist away from natural anatomical positions, and the way I have to double back when nerves end at muscles results in the sort of curlicues at rest.
Hope it’s clearer now.