Internal obliques

A pair of muscles located on the lateral sides of the abdomen, playing a crucial role in trunk movement and stability.

Internal obliques are a pair of flat muscles located beneath the external obliques on either side of the abdomen. They extend from the lower ribs downwards to the pelvis and play a vital role in various bodily movements. These muscles are responsible for flexing, rotating, and laterally bending the trunk, allowing for coordinated torso movements.

Terminologia Anatomica

musculus obliquus internus abdominis

System

Muscular system

Function

The internal oblique muscles are integral to maintaining stability during movement and supporting various activities involving the trunk. They function by working in concert with the external obliques and other core muscles to facilitate twisting, bending, and stabilization. This muscle group is particularly important for activities that require rotational force, such as sports or lifting. The internal obliques also contribute to respiratory movements by assisting in forced expiration. When contracting, they can help compress the abdominal contents, providing additional support for the spine and contributing to overall core strength.

Location

The internal oblique muscles are positioned beneath the external obliques and are oriented in a diagonal pattern. They descend from the lower ribs and insert into the iliac crest of the pelvis. The fibers run in an opposite direction compared to the external obliques, creating a crisscross pattern that is essential for trunk stability. The muscles lie within the lateral abdominal wall, forming a significant part of the abdominal musculature that contributes to both posture and movement.

Did You Know?

The internal obliques work bilaterally to flex the trunk forward and unilaterally to rotate it to the opposite side.
These muscles are involved in maintaining core strength, which is crucial for preventing injuries during physical activities.
Stress and heavy lifting can lead to strains in the internal obliques, highlighting the importance of proper form and core stability.