One test you can do is lay your arm on a flat surface and touch your pinky finger to your thumb and tip your hand slightly up.
One of two things will happen, either the tendon in your wrist will raise up, or there will be no visible tendon there.
If you see a raised band in the middle of your wrist, you’ve got a vestigial muscle in your forearm.
That tendon connects to muscle called palmaris longus, and 10 to 15 percent of people are missing on one or both of their arms.
But lacking this muscle doesn’t make the person any weaker, and there is no difference in grip strength.
It is actually one of the first tendons that surgeons will take out when doing reconstructive and cosmetic surgeries.
The palmaris longus is in many mammal species, but is most developed in the animals that use all four limbs to walk around.In primates, the muscle is longer in animals like monkeys and lemurs, and is shorter in animals like chimps, gorillas, and other animals that don’t do a lot of running and climbing through the trees.
If you are one of the people that has this tendon, than you learned more about your past and how humans have evolved in this particular way. If you do not have the tendon, it is nothing to worry about. This tendon was really important for early humans that perhaps needed to swing from the trees in order to survive.
A few other interesting parts about our ancestral past is how we don’t need body hair to survive unlike previous humans did, and goose bumps were necessary in order for their skin to retain heat. Or the fact that we don’t need wisdom teeth to eat, and most people get them removed.
