ABNORMAL MUSCLES 459 



This is the most frequent of all the muscles to which the term ' abnormal ' is applied. [For 

 figure, see \\'()0(l, Pj-oc Roy. Soc. vol. xv. p. 521.] 



The extensor annularis arises from the posterior surface of the ulnar shaft below the ex- 

 tensor indicis. Wheu an extensor medius is also present, it will arise in common with the 

 annularis. 



The teudon pa.sses under the annular ligament with the common extensor, and is inserted 

 into the tendun of the ring (fourth) linger. 



The extensor brevis digitorum manus arises from the ligamentous tissues on the back of the 

 carpus, or from one of the bones of the forearm, or from the posterior annular ligament. It 

 pa.sses under the posterior annular ligament, and gives off three slips which blend with the 

 tendons of the third, fourth, and fifth iligits. 



The extensor carpi radialis accessorius arises from the humerus below the extensor carpi 

 radialis longior. 



It is inserted into the metacarpal bone of the thumb, or into the abductor pollicis, or into the 

 first dorsal interosso(jus muscle. 



Extensor carpi radialis intermedius. — This muscle usually arises from one or both the 

 radial exten.sois of the carpus, and more rarely from the humerus. It is inserted into the second 

 or third metacarpal bone. 



The extensor coccygis arises from the posterior surface of the last piece of the sacrum. 



It is inserted into the posterior .surface of the coccyx. 



The extensor medii digiti arises from the ulna below the extensor indicis, or from the pos- 

 terior annular ligament. It is inserted into the extensor exi)ansion of the middle finger. 



The extensor ossis metatarsi hallucis arises as a slip from the extensor proprius hallucis or 

 from the extensor ce/inmiinis diyitorum, or from the tibialis anticus. It may arise as a separate 

 muscle close to the extensor proprius. 



It is inserted into the metatarsal bone of the hallux. 



The extensor primi internodii hallucis longus is usually an oifset from the extensor jwopriiis, 

 but it may arise separately from the fibula and intero-sseous membrane or from the tibialis anticus. 



It is inserted into the inner part of the base of the first phalanx of the hallux. [See Wood, 

 Proc. Rfj}/. Soc. vol. XV. p. .535.] 



The flexor accessorius longus arises from the fascia over the flexor longus hallucis, or fi'om 

 the fibula or tibia ; it pa.sses with the tendon of this muscle beneath the internal annular 

 ligament ; and ends in a tendon which crosses the long plantar ligament obliquely, to be 

 inserted into the sesamoid bone in the tendon of the pjeroneus longus, or it joins tlie long flexor 

 or the accessorius. 



When this muscle is present, the acces.sorius is sometimes absent. [For figure, see Thane, 

 Proc. Ann t. Soc. of Gt. Britain and Ireland, May IS'Jl.'] 



The flexor carpi radialis brevis vel profundus arises from the front surface of the radius 

 near the anterior border, above the pronator quadratus, but below the flexor longus pollicis. 



The insertio/i is veiy variable : in some cases it onlj' reaches the annular ligament, whilst in 

 others itija.sses under this structure to be inserted into the trapezium, magnum, or the base of the 

 second or third metacarpal bones. [For figure, see Wood, Journ. of Anat. and P/ii/s. vol. i. p. 

 57.] 



The gluteo-perinealis arises from the fascia at the lower border of the gluteus maximus. It 

 joins the transversu.s {lerinei or is inserted into the triangular ligament. 



The gluteus quartus arises from the anterior part of the inferior gluteal ridge of the ilium ; 

 it lies in close contact with the capsular ligament of the hip-joint. 



It is inserted into the top of the great trochanter of the femur anterior to the insertion of the 

 gluteus minimus. [For good figure, see Graber, Virchoiv Arch. bd. cvii. s. 480.] 



Hyo-epiglottideus. — This muscle arises from the middle of the ridge on the lingual aspect of 

 the epiglottis. 



It is inserted into the median tubercle on the body of the hyoid bone. It is often represented 

 by n fibrous Vjand. [See Journ. of Anat. and PInjs. vol. xxiii. p. 256.] 



The iliacus minor, or ilio-capsularis, arises from the anterior inferior spine of the ilium. 



It is inserted itito the lower part of the anterior intertrochanteric line, or into the ilio-femoral 

 portion of the capsule. 



The interclavicular muscle usually consists of two fleshy bellies with a stout intermediate 

 tendon. It arise^s from the clavicle, anteiior to the attachment of the rhomboid ligament and 

 from the ligament itself 



It is inserted into a corresponding position on the opposite clavicle, and fllls up the gap be- 

 tween the .sternal ends of the clavicles. [Lane, Journ. of Anat. and Pht/s. vol. xx. j). 544.] 



The interosseus primus volaris is a slender muscle arising from the ulnar side of the base of 

 the first metacarpal bone. 



It is inserted into the side of the base of the first phalanx of the thumb in common with the 

 adductor pollicis. 



Its origin and insertion are marked in fig. 1,35, p. 130. 



The ischio-aponeuroticus, or tensor fasciae cruralis, arises from one of the hamstring muscles, 

 and is inserted into the fascia on the back of the leg. 



Kerato-thyroid. — A short, slender muscle arising from the lower border of the cricoid carti- 

 lage behind the articular facet. 



It is inserted into the inferior cornu of the thyroid cartilage. 



