Q11 External Oblique

Question 1

Give the position of this muscle

Answer 1

This flat muscular sheet is situated on the anterolateral aspect of the abdominal wall. Most superficial of the three sheets of muscle of the anterior abdominal wall

Question 2

State the attachment of External Oblique muscle

Answer 2

Proximal Attachment: upper attachment is by fleshy strips to the outer boarders of the lower eight ribs and their costal cartilages. It interdigitates with Serratus Anterior above and Latissimus Dorsi below.

Distal Attachment: outer lip of the anterior two-thirds of the iliac crest.
Remainder of fibres give rise to a large aponeurosis, the fibres sweep across Rectus Abdominis, participating in the rectus sheath, and pass towards the midline to fuse with that of the opposite side of the linea alba
The lower free border of the aponeurosis stretches between the pubic tubercle and the ASIS and forms the inguinal ligament.

Question 3

List the actions of this muscle on the trunk with plevis fixed

Answer 3

Rotation (to opposite side) and Lateral flexion (to the same side) of the shoulders and thorax
ipsilateral hip hitching

Question 4

List the actions of this muscle on the pelvis with shoulders/trunk fixed

Answer 4

Rotation of Pelvis to same side and hip hitching of the same side