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Extensor Digitorum

Region

Origin & Insertion

['Origin: Lateral epicondyle of humerus', 'Insertion: Extensor expansions of fingers 2–5']

Synergistic Muscles

['EI', 'EDM']

Joints

['Wrist', 'MCP, PIP, DIP of fingers 2–5']

Primary Actions

['Extends fingers 2–5', 'Assists wrist extension']

Nerve & Spinal Segment

Radial nerve (posterior interosseous branch)

Brachial plexus; C7–C8

Interesting

Main extensor of fingers. [Gray's]

Reversal of Action

Anchor fingers while moving palm down

Common Dysfunctions

Inability to fully extend fingers, weak hand opening

How to Stretch

Flex fingers and wrist together.

Trigger Points

How to Strengthen

Extension with resistance bands or putty.

Concentric Action

Extend fingers

Applications:

Trains hand opening after stroke or injury

Eccentric Action

Lower fingers slowly from extension

Isotonic Action

Finger lifts against rubber band

Related Conditions

['Extensor lag', 'Tendonitis']

Isometric Action

Hold fingers in extended posture

Exercise Ideas

['Finger extensions', 'Rubber band opens', 'Putty extension drills']

Spry Juncture, LLC

How to Evolve Gracefully