Quick Facts
Origin: Medial aspects of base and body of fourth metatarsal bone.
Insertion: Medial aspect of base of proximal phalanx of fourth toe and extensor expansion of fourth toe.
Action: Adducts fourth toe at its metatarsophalangeal joint; simultaneously flexes metatarsophalangeal joint and extends interphalangeal joints of fourth toe.
Innervation: Deep branch of lateral plantar nerve (S2-S3).
Arterial Supply: Deep plantar arch, lateral plantar, plantar metatarsal, and dorsal digital arteries.
Related parts of the anatomy
Origin
The second plantar interosseous muscle originates from the medial aspects of the base and body of the fourth metatarsal bone.
Insertion
The fibers of the second plantar interosseous muscle travel anteriorly to the fourth toe and insert, via a short tendon, onto the:
- medial aspect of the base of the proximal phalanx of fourth toe;
- extensor expansion of fourth toe.
Key Features & Anatomical Relations
The second plantar interosseous muscle is located in the fourth layer of muscles that are found in the plantar part of the foot. It is a short, unipennate skeletal muscle.
It is located:
- superior to the adductor hallucis muscle and the third lumbrical muscle of foot;
- inferior to the third dorsal interosseous muscle of foot;
- medial to the fourth metatarsal bone;
- lateral to the third metatarsal bone.
Actions
The second plantar interosseous muscle is involved in multiple actions:
- adducts the proximal phalanx of fourth toe (i.e., draws it towards the longitudinal axial line of the second toe) at the fourth metatarsophalangeal joint;
- simultaneously flexes the fourth metatarsophalangeal joint and extends the interphalangeal joints of the fourth toe (Standring, 2016).
List of Clinical Correlates
- Clawing of the toes
- Charcot-Marie-Tooth disease
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
Actions
The second plantar interosseous muscle is involved in multiple actions:
- adducts the proximal phalanx of fourth toe (i.e., draws it towards the longitudinal axial line of the second toe) at the fourth metatarsophalangeal joint;
- simultaneously flexes the fourth metatarsophalangeal joint and extends the interphalangeal joints of the fourth toe (Standring, 2016).
