Phylogenetic variation in flexor digitorum brevis: a Nepalese cadaveric study
S W Lobo1, R G Menezes, S Mamata
1Department of Anatomy, Manipal College of Medical Sciences, Pokhara, Nepal. stanmcoms@yahoo.com
Nepal Medical College Journal : NMCJ
|June 30, 2009
Summary
The study found the flexor digitorum brevis (FDB) tendon for the fifth toe was absent in all Nepalese cadavers examined. This suggests evolutionary adaptation in foot muscles due to reduced little toe function in humans.
Area of Science:
- Anatomy
- Evolutionary Biology
- Biomechanics
Background:
- Understanding foot muscle architecture is crucial for surgical procedures, biomechanical modeling, and prosthesis design.
- The flexor digitorum brevis (FDB) is a superficial intrinsic muscle of the foot sole.
- Human little toes exhibit reduced function and lack opposition compared to digits in other primates, indicating evolutionary changes in associated muscles.
Purpose of the Study:
- To investigate phylogenetic variations in the flexor digitorum brevis (FDB) muscle architecture.
- To document the presence or absence of the FDB tendon attachments to the fifth toe in Nepalese cadavers.
Main Methods:
- Dissection of 60 adult embalmed cadavers (20 male, 10 female) from Nepal.
- Observation and documentation of the flexor digitorum brevis (FDB) muscle and its tendon attachments to the toes.
Main Results:
- The tendon for the fifth toe (little toe) was consistently absent in all 60 dissected foot soles.
- The function of the FDB related to the fifth toe appears to be compensated by other long flexor muscles of the foot.
Conclusions:
- The absence of the FDB tendon to the fifth toe in Nepalese cadavers suggests an evolutionary reduction in the usage and importance of the little toe.
- These anatomical variations in FDB are clinically relevant, particularly for FDB musculocutaneous flap procedures in heel pad reconstruction.
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