Flexor Digitorum Brevis (Pedis)

The Slip from flexor brevis to the little toe may be defective or absent. It may be present but fail to reach the toe, ending in fascia. It may arise separately from the fibular band of the plantar aponuerosis. It is absent in about 21% of cases, but may be replaced by a small fusiform muscle arising from the long flexor tendon, with occasional additional attachments to the medial tubercle of the calcaneus, lateral intermuscular septum, or accessorius (quadratus plantae). The muscle or its tendons may be more or less joined to the tendons of flexor digitorum longus. Variation in this muscle occurs in 63% of limbs (all sources).

Macalister indicates that the flexor tendon for the little toe is often complex, being made up of:

1. A muscular band from below the sustentaculum tali
2. A slip from the cuboid; and
3. A slip from the long flexor tendon. Macalister saw the perforating tendon for the little toe from accessorius alone.

Macalister (1875) reported the variations of this muscle as follows:

1. Absence of the little toe tendon (Wood), with no substitute
2. With its place supplied by a small fusiform muscle from the outermost border of flexor perforans (Wood)
3. The substitute arising by two slender fusiform bellies, one from the long flexor tendon, and the other from the inner tubercle of the os calcis, deeper than the fibers of the flexor digitorum brevis
4. A slip of perforans for the middle toe joined the perforatus at the metacarpophalangeal joint
5. A long slip of the perforans tendon, joined the flexor brevis to the middle toe slip of flexor brevis
6. The same from accessorius
7. This muscle has been seen with only three tendons
8. Or with five tendons, two to the second toe (Kelly)
9. Or with the little toe tendon not perforated
10. Or lost in the anterior fascia of the toe
11. The little toe short flexor has been seen by Brugnone, Henle, and others arising from the long flexor tendon
12. Or it has been found separate, and arising by one head from the lateral intermuscular septum, and from the flexor accessorius.

Syn.: m. Flexor digitorum pedis brevis, Flexor digitorum communis brevis, Flexor digitorum sublimis brevis, Flexor digitorum perforatus brevis, Pediaeus internis.

Riferimenti dell’opera originale

Elenco riportato come compare nella fonte, senza normalizzazione dei formati bibliografici.

• Curnow J. (1873) Notes of some irregularities in muscles and nerves. J. Anat. Physiol. 7:304-309.
• Henle, J. (1871) Handbuch der Muskellehre des Menschen, in Handbuch der systematischen Anatomie des Menschen. Verlag von Friedrich Vieweg und Sohn, Braunschweig.
• Kochi, K. and H. Adachi. (!887) On the flexor digitorum communis accessorius. Juzenkai Zasshi. 4:49-51. In Japanese.
• Komiya, R. (1954) On the variation of the flexor digitorum brevis. Kaibogaku Zasshi 29:175. In Japanese.
• Macalister, A. (1875) Additional observations on muscular anomalies in human anatomy (third series), with a catalogue of the principal muscular variations hitherto published. Trans. Roy. Irish Acad. Sci. 25:1-134.
• Nathan, H. and H. Gloobe. (1974) Flexor digitorum brevis- anatomival variations. Anat. Anz. 135:295-301.
• Nathaniel, D.A. (1954) A note on the variation of the flexor digitorum brevis. J. Anat. Soc. India 3:103-105.
• Ouchi, H. (1953) On the variation of the muscles (M. sternocleidomastoidens, M. flexor digitorum brevis, M. quadratus plantae). Kaibogaku Zasshi. 28:Supple. Kanto 9-10. In Japanese.