Eur J Anat, 18 (3): 171-174 (2014)

Morphometry of the deep muscles of the extensor compartment of the forearm and related variations

Harpreet S. Gulati¹, Biswabina Ray², Sushma³, Anthony S. Dâ??Souza³ and Naveen Kumar⁴

¹Department of Anatomy, M.M.Medical College & Hospital, Solan, India, ²Department of Anatomy, ESIC Medical College- PGIMSR, Bengaluru, India, ³Department of Anatomy, Kasturba Medical College, Manipal, India and ⁴Department of Anatomy, Melaka Manipal Medical College, India

ABSTRACT The architecture and dimensions of the muscle-tendon unit has a close relation with muscle performance. The aim of this study was to conduct morphometry and note the variations of the deep muscles of the extensor compartment of the forearm. The origin, insertion, anatomical variations, length of muscle belly and tendon of the deep extensors of the forearm, i.e. abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis were noted in 38 sides of 19 cadavers. Results were statistically analysed and tabulated. There were no extra bellies of any muscle, but one 60-year-old male cadaver showed a variant muscle extensor digitorum brevis manus with the absence of extensor indicis. The variant muscle did not have any extra tendon or extra muscle belly. It was excluded from statistical analysis. The average muscle length and tendon length of abductor pollicis longus were 15.37 cm & 6.2 cm respectively; those of the extensor pollicis brevis were 15.37cm & 9.07 cm respectively; those of the extensor pollicis longus were 12.47 cm & 12.88 cm respectively; and those of extensor indicis were 10.06 cm & 14.4 cm respectively. Tendons and muscles work together to absorb or generate tension in the system. Muscle and tendon length are involved in the amount of force production.

Keywords: Abductor pollicis longus, Extensor pollicis brevis, Extensor pollicis longus, Extensor indicis, Tendon, muscle