Abductor Pollicis Longus
Region
Origin & Insertion
['Origin: Posterior surface of ulna, radius, and interosseous membrane', 'Insertion: Base of 1st metacarpal']
Synergistic Muscles
['Extensor pollicis brevis', 'Opponens pollicis']
Joints
['Wrist', '1st CMC joint']
Primary Actions
['Abducts and extends thumb at CMC joint']
Nerve & Spinal Segment
Radial nerve (posterior interosseous branch)
Brachial plexus; C7–C8
Interesting
Contributes to lateral wrist contours. [Moore’s]
Reversal of Action
Move hand toward thumb with fixed digit
Common Dysfunctions
Thumb instability, De Quervain’s syndrome
How to Stretch
Thumb across palm and wrist ulnar deviation.
Trigger Points
How to Strengthen
Thumb abduction band work.
Concentric Action
Abduct thumb away from palm
Applications:
Essential in thumb repositioning post-injury; involved in De Quervain’s syndrome
Eccentric Action
Control return of thumb toward palm
Isotonic Action
Thumb lifts with resistance band or putty
Related Conditions
['De Quervain’s', 'Tendonitis']
Isometric Action
Hold thumb in abducted position
Exercise Ideas
['Thumb abduction hold', 'Rubber band opens', 'Theraputty push']