For attachment of infraspinous
muscle (facies musculi infraspinati), there is an oval area found lateral to major tubercle.
The latissimus dorsi tendon goes under the deltoids and it is sutured to the infraspinous
on the lateral superior part.
When contraction of the supraspinous and infraspinous
muscles was obtained, the current was gradually decreased until the muscle twitched at 0.3-0.4 mA for 0.1 ms at 1 Hz.
Although the anterior subscapularis originates from the subscapular fossa to insert onto the lesser humeral tubercle, the remaining posterior muscles arise from the supraspinous and infraspinous
fossae, respectively, and attach onto the greater humeral tubercle (Sinnatamby, 2006; Standring et al.; Muscolino).
For example, during the placement of posterior portals, risks of injuring the posterior humeral circumflex artery (Naidoo et al, 2014), the circumflex artery of the scapula (Ebraheim et al, 2010), the suprascapular nerve (Bigliani et al., 1990; Shishido & Kikuchi, 2001; Gumina et al., 2011), branches of the infraspinous
artery (Naidoo et al.), and muscle vessels that provide irrigation to the joint capsule have been documented (Andary & Petersen, 2002).