Palmaris Longus
Forearm & Wrist
About 10-15% of people are missing this muscle entirely — and it makes zero difference in grip strength.
Function
Flexes wrist, tenses palmar aponeurosis
Origin
Medial epicondyle of humerus
Insertion
Palmar aponeurosis and flexor retinaculum
Innervation
Median nerve (C7-C8)