What Animal Has The Longest Palmaris Longus Muscle?

Happy January, everybody! I've been absent from the blog for a few weeks due to the arduous process of travelling from Thailand to Kazakhstan, and then back to the U.S. after a quick terminate in Madrid – a journey of seven flights spaced out over 8,800 miles. The trip was logistically challenging, just I was able to make my mode back to balmy 1˚C Ann Arbor this by Thursday, baggage in tow.

On my longest Trans-Atlantic flight my TV wasn't working, so after finishing my book and intently perusing the in-flying mag (Did you know that Louisville is a happening hipster town, and that bartenders in NY are putting tobacco in fancy cocktails?) I was at a loss for what to do. I watched half of a sitcom without sound to exercise my lip-reading skills (I am at present able to determine when people are saying "OK" sarcastically, particularly if they hold upwards one of their palms for emphasis), drifted in and out of fitful sleep while cradling my elbow to protect it from the ambitious overtures of the beverage cart, and spent a lot of time staring at anything that crossed my range of vision, including the back of the tray table, my neighbour'southward Television screen, and my easily. While examining my easily and flexing them dorsum and forth, I was reminded of another point of palpable anatomy, also the anatomical snuffbox, that can be institute in this region – the Palmaris longus tendon.

Palmaris longusis an unusual musculus. It originates on the medial epicondyle of the humerus and inserts into the anterior aspect of the flexor retinaculum (the gristly sheath that forms the top of the carpal tunnel) and into the palmar aponeurosis. It functions equally a superficial flexor of the manus at the wrist and tightens the palmar aponeurosis. To notice your own Palmaris longus tendon, follow these two unproblematic steps:

Step one: Extend your hand flat out in front of y'all, so that your unabridged wrist is visible.

Step 2: Curl your hand into a fist and examine the topography of your wrist.

The tendon ofPalmaris longus will appear every bit a raised ridge running forth the center of the anterior aspect of your wrist. A slightly more involved strategy is to use Schaeffer's test, in which yous touch your thumb to your pinkie earlier flexing your wrist.

If you lot're finding this complicated (which it very well may be, every bit I'm currently operating nether a mild haze of jetlag), there'due south a useful video explaining the technique:

If the surface of your wrist remains smooth and flat fifty-fifty when your hand is flexed, then there is something dreadfully wrong with you and you should consult a medical professional immediately. It's entirely possible that yous represent a novel species of X-Men style mutant, capable of flexing your wrist using but the awesome force of your heretofore undiscovered telekentic powers!

Simply KIDDING.Palmaris longus is an interesting muscle because information technology's actually vestigial in humans. It'south absent in about 10-15% of the population, then if you don't come across that raised tendinous ridge, you're probable not a mutant. Interestingly plenty, my Netter flashcards also tell me that in other species this muscle is used to retract the claws, which is no dubiousness why you can meet what looks to be a pretty boss Palmaris longus tendon on Wolverine's left wrist in the photo above.

If yous're curious about the evolutionary history of this attribute of anatomy, my friend Dr. Zach Throckmorton and some of his colleagues are conducting some new enquiry on this musculus, focusing on the global patterning and evolutionary causality of unilateral and bilateral agenesis of the Palmaris longus musculus in humans. The jpeg of the affiche is below, and I've uploaded a pdf in the references department at the stop of the post.

So if y'all find that you're missing i or both of yourPalmaris longusmuscles, my advice is to try to palpate information technology with a grouping of friends who are non anatomy nerds, and so explode into a frenzied and terrified panic when you "detect" that one of your muscles is missing. If they're super gullible, you can even tell them you're some kind of a mutant.

(As a caveat, I would suggest against claiming to exist a Wolverine-way mutant since you'd have a devil of a fourth dimension retracting your claws).

References
Palmaris Longus. Netter's Beefcake Flashcards, tertiary Edition. half dozen-29. Saunders.

Ali M. Soltani, Mirna Peric, Cameron S. Francis, et al., "The Variation in the Absence of the Palmaris Longus in a Multiethnic Population of the United states of america: An Epidemiological Study," Plastic Surgery International, vol. 2012. (Total Text available online, here)

Throckmorton, Z., Due north. Forth, A.Schandi, and N.Thomas. 2014. Palmaris Longus Agenesis Variation and Evolution: Adventures at the anthropology-anatomy interface. Affiche at the American Association of Concrete Anthropologists Meetings, Calgary, AB. (Pdf available here: Throckmorton et al., 2014)

Image Credits
Image of Wolverine from Empire Online, here.

Source: https://bonebroke.org/2015/01/19/palpable-anatomy-the-palmaris-longus-tendon/

Posted by: thomasthadvating.blogspot.com

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