Palmaris longus
Musculus palmaris longus · Dlouhý dlaňový sval
Muscles
Looks like
A small forearm muscle with a long thin tendon running to the palm; missing in about 1 in 7 people.
What it does
Tenses the palm's fibrous sheet and weakly bends the wrist.
Keeping it well
Its absence is harmless; its tendon is often used as a graft for repairs elsewhere.