Extensor indicis et medii communis muscle

The extensor indicis et medii communis is a rare anatomical variant in the extensor compartment of forearm. This additional muscle lies in the deep extensor layer next to the extensor indicis proprius and the extensor pollicis longus. The characteristics of this anomalous muscle resemble those of the extensor indicis proprius, with split tendons to the index and the middle finger. This muscle can also be considered as a variation of the aberrant extensor medii proprius.

Extensor indicis et medii communis
Extensor indicis et medii communis (EIMC) and extensor indicis proprius (EIP)
Details
Originposterior distal third of ulna and interosseous membrane
Insertionindex finger and middle finger
Arteryposterior interosseous artery
Nerveposterior interosseous nerve
Actionsextends index finger and middle finger
Identifiers
Latinmusculus extensor indicis et medii communis
Anatomical terms of muscle

Structure

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The extensor indicis et medii communis originates from the distal third of ulna next to the extensor indicis proprius.[1] After passing the wrist joint through the fourth extensor compartment, the tendon splits into two to insert to the extensor expansion of the index and the middle finger.[2]

Prevalence

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The extensor indicis et medii communis has an incidence between 0% and 6.5%.[2][3] Meta-analysis showed that the muscle was present in average of 1.6% of the total 3,760 hands, and was more prevalent in North American populations.[3]

Function

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The extensor indicis et medii communis extends the index and the middle finger.

See also

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References

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  1. ^ Tan, S. T.; Smith, P. J. (May 1999). "Anomalous extensor muscles of the hand: a review". The Journal of Hand Surgery. 24 (3): 449–455. doi:10.1053/jhsu.1999.0449. ISSN 0363-5023. PMID 10357521.
  2. ^ a b Yalçin, Bülent; Kutoglu, Tunç; Ozan, Hasan; Gürbüz, Hülya (Mar 2006). "The extensor indicis et medii communis". Clinical Anatomy. 19 (2): 112–114. doi:10.1002/ca.20173. ISSN 0897-3806. PMID 16283647.
  3. ^ a b Yammine, Kaissar (Apr 2015). "The prevalence of the extensor indicis tendon and its variants: a systematic review and meta-analysis". Surgical and Radiologic Anatomy. 37 (3): 247–254. doi:10.1007/s00276-014-1352-0. ISSN 1279-8517. PMID 25096501.
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