Ml ></./> i-- rin i \ ///,/'//; /,/.//;> _'.' i 



is prismatic, muscular, divided by fibrous intersections, and easily separated 

 into several irregular fasciculi. In its superior half it is flattened, entirely 

 tt hdinoiis. and split into several (limitations, the longest of which are behind. 



Attackmentt, It originates: 1, Through the niedium of its tendinous 

 (limitations, from the posterior border of the scapula and tho linear imprints 

 in the posterior spinous fossa; 2, From the smill tubercle situated on the 

 external side of the margin of tho glenoid cavity, by a short tendon. It 

 terminates on the humerus, between the crest of the external tubercle and 

 the deltoid imprint. 



Iti'liilinii*. Outwardly, with the subspinatus and the long abductor; 

 inwardly, with the largo extensor of the fore-arm, the short extensor, and the 

 capsule of the Kcapulo-hunu nil articulation. 



.1 '//. Like the preceding, this muscle is an abductor and outward 

 r of the humerus. 



4. Superspinatus. (Figs. 119, 2 ; 121, 5.) 



-. Sii]M>r;u'romia-trochiteriu8 Girard. (Antea epinatus Percivall. An- 



- i>i 'nnt a x I.i i/h.) 



Situation. This muscle is thick and prismatic, stronger below 

 than above, representing a very elongated pyramid, and completely filling, 

 and even projecting beyond, tho super- scapular fossa. 



'ii,-<- A illicit UK-HI*. -It is almost entirely formed of fleshy fibres, 



which are attached, by their superior extremities, to the cartilage of prolong- 



mi nt of the scapula, the inner face of the scapular aponeurosis, the super- 



;, and the anterior border and cervical angle of the scapula 



iiiv'-rtinii. These fibres, on reaching the inferior extremity of tho 



muscle, form two very thick, short, and slightly tendinous branches, united 



'h other by the enveloping coraco-radial or biceps aponeurosis. The 



xternal branch reaches the summit of tho external tubercle : the internal is 



in-' rt- d into the* corresponding part of the internal tuberosity movable 



'''it. 



li> liifii.iix. Outwards, with the scapular aponeurosis, to which its fibres 

 adhere in the most intimate manner; inwards, with the scapula and tho sub- 

 seapularis muscle ; forwards, with the small pectoral ; and behind, with the 

 :iei,.mion spine and the subspinatus. Tho two terminal branches cover and 

 embrace the cnraco radialis tendon, and the capsule of tho scapulo-humeral 

 articulation. 



Action. Tins muscle is an extensor of the hnmerus, and a tensor of tho 

 enveloping coraco-radial aponeurosis. With regard to the articulation of the 

 shoulder, it plays the part of a powerful ligament: a function it shares with 

 the majority of tho other scapular muscles. 



5. Sulspinatu*. (Fig. 119, 3, 3'.) 



.'/nynw. Sul>-acr(iiiiiH-tr.-liiti rius Girarrf. (Potiea tpiiMlut FtrcivaU, Po- 



i.in'Unx- l.'ijh.) 



ii"ii Form. Situated, as its name indicates, in the subfipinatus 

 fossa, this muscle is wide, thin, and flattened on both sides at its siij.. 



lity. thick and prismatic in its middle, and conoid at its inferior 

 iiity. which is terminated by two short branches an external and 

 internal. 



