lumbricalis manus

Introduction

Four intrinsic muscles of the palm.

Origin

• lateral 2: from radial side of the tendons of the flexor digitorum profundus going to the index & middle fingers
• medial 2: from the adjacent sides of the 2nd & 3rd & 3rd & 4th tendons of the flexor digitorum profundus

Insertion

• radial side of extensor tendon on dorsum of each of the 4 fingers

Action

• flexes the metacarpophalangeal joint
• extends the proximal & distal interphalangeal joints

Innervation

• the 2 radial muscles by the median nerve
• the 2 ulnar muscles by the ulnar nerve

More general terms

• skeletal muscle (voluntary muscle)