Abdominal Musculature

Question 1

Abdominal Musculature

Answer 1

origin - pubic symphysis of the pelvis

insertion -

• • ribs 5-7
• • xiphoid process of the sternum

isolated function - concentrically accelerates spinal flexion, lateral flexion, and rotation

integrated function -

• • eccentrically decelerates spinal extension, lateral flexion, and rotation
• • isometrically stabilizes the lumbo-pelvic-hip complex

Question 2

External Oblique

Answer 2

origin - external surface of ribs 4-12

insertion - anterior iliac crest of the pelvis, linea alba, and contralateral rectus sheaths

isolated function - concentrically accelerates spinal flexion, lateral flexion, and contralateral rotation

integrated function -
– eccentrically decelerates spinal extension, lateral flexion, and rotation
isometrically stabilizes the lumbo-pelvic-hip complex

Question 3

Internal Oblique

Answer 3

origin - anterior 2/3 of the iliac crest of the pelvis and thoracolumbar fasia

insertion - ribs 9-12, linea alba, and contralateral rectus sheaths

isolated function - concentrically accelerates spinal felxion, lateral flexion, and ipsilateral rotation

integrated function -

• • eccentrically decelerates spinal extension, rotation, and lateral flexion
• • isometrically stabilizes the lumbo-pelvic-hip complex

Question 4

Transverse Abdominis

Answer 4

origin - ribs 7-12, anterior 2/3 of the iliac crest of the pelvis, and thoracolumbar fascia

insertion - lineae alba and contralateral rectus sheaths

isolated function -

• • increases intra-abdominal pressure
• • supports the abdominal viscera

integrated function - isometrically stabilizes the lumbo-pelvic-hip complex

Question 5

Diaphragm

Answer 5

origin -

• • costal part: inner surfaces of the cartilages and adjacent body regions of ribs 6-12
• • sternal part: posterior side of the xiphoid process
• • crural/ lumbar part: 1- two aponeurotic arches covering the external surfaces of the quadratus lumborum and psoas major, 2 - right and left crus, originating from the bodies of 1.1-1.3 and their intervertebral disks.

insertion - central tendon

isolated function - concentrically pulls the central tendon inferiorly, increasing the colume in the thoracic cavity

integrated function - stabilizes the lumbo-pelvic-hop complex