Spry Juncture, LLC
How to Evolve Gracefully
Lumbricals
Region
Origin & Insertion
['Origin: Tendons of flexor digitorum longus', 'Insertion: Medial extensor expansion of toes 2–5']
Synergistic Muscles
['Flexor digitorum longus', 'Extensor digitorum longus']
Joints
['MTP, PIP, DIP of toes 2–5']
Primary Actions
['Flex MTP joints', 'Extend IP joints of toes 2–5']
Nerve & Spinal Segment
1st: Medial plantar nerve; 2nd–4th: Lateral plantar nerve
Sacral plexus; S2–S3
Interesting
Named from 'worm-like' shape. [Moore’s]
Reversal of Action
Arch lift via toe stability
Common Dysfunctions
Clawed toes, toe coordination loss
How to Stretch
Full toe flexion followed by extension.
Trigger Points
How to Strengthen
Toe yoga and active control.
Concentric Action
Flex MTP, extend IP joints of toes
Applications:
Used in claw toe correction and toe-off control
Eccentric Action
Control return to clawed posture
Isotonic Action
Toe yoga or coordination drills
Related Conditions
['Claw toe deformity', 'Hammer toe']
Isometric Action
Hold toes neutral during active flexion
Exercise Ideas
['Toe lifts', 'Isolated MTP flexion', 'Toe splaying']