Supinator longus, in actual measurement, reaches one-third up the humerus, giving a short appearance to the upper arm.
The deltoid muscle reaches nearly half-way down humerus bone, and in outline a slight depression will be seen in the middle, the lower half having the most prominent curve (Figs. 7 and 9).
Muscles of inner arm are shown in Fig. 7.
R : Pronator teres.
S : Internal condyle of humerus.
T: Palmaris longus.
U : Flexor sublimis digitorum.
V : Flexor carpi ulnaris.
F: Deltoid.
G : Pectoralis major.
H : Biceps, running nearly half-way into arm.
The other letters stand for the same names as for Fig. 6. See dotted outline of ribs starting under arms, and note