I love these ones, but not sure I could relax around them :)

Artwork by anonymous bark beetles

Intrinsic posturing.... There are "intrinsic" muscles that are within our hands (as opposed to "extrinsic" muscles in the forearm). These are important for fine dexterous movement. One of their critical functions is to enable "intrinsic plus" movement. This is a coordinated movement where we flex our MP joint (the knuckle where the finger meets the hand... the one you'd punch with for lack of a better way of describing it) and extend our IP joints (the two knuckles further out in our fingers). Try grasping a ball, cup, water bottle, etc. First try to do it with this "intrinsic plus" positioning with MP joints flexed and IP joints extended and then initiate grasp. Then try to do it with an "intrinsic minus" positiong with the MP joints extended and then flexing only the IP joints. Tenodesis... Think about the extrinsic tendons as they cross the wrist. Tension will change as you flex and extend the wrist or deviate side to side (radial - ulnar deviation). Now reach down to grab something out of a drawer; your wrist will flex and fingers will extend. You're consciously doing some component of this, but a component of this is due to the wrist flexion unloading the finger flexors, which results in them relaxing. But now think about power grip and look at the position of your wrist. You have it extended, which tightens your finger flexors. You also will ulnarly deviate it (toward your "pinky" finger), which also serves to increase pull through force in your finger flexors, particularly the ring and small fingers due to the "hook of hamate", a piece of bone around which these tendons are routed. These and some other subtleties I think are really important for dexterous hand function. Patients who lose these capabilities have downgraded hand function.

Have you seen anything more beautiful?!! 🤩😍🙌🏽 A magnetohydrodynamics (MHD) simulation of solar-wknd compression, magnetic reconnection, plasmoid release, particle acceleration, and auroral activity around Earth.