palmar longus (long palmar muscle)

Introduction

Congenitally absent in 20% of individuals.

Origin

medial epicondyle of humerus

Insertion

flexor retinaculum of wrist & palmar fascia

Action

• makes palmar fascia tense
• flexes the hand & forearm
• when tensed, its tendon stands out at wrist & overlies median nerve

Innervation

median nerve

More general terms

• skeletal muscle (voluntary muscle)