OSTEOLOGIA DE MIEMBRO INFERIOR 1

Osteology of the Lower Limb: The Pelvis

Introduction to the Pelvis

• The video begins with a greeting and an introduction to the topic of osteology, specifically focusing on the lower limb and pelvis, dedicated to students from Universidad Libre in Cali, Colombia.

Structure of the Coxal Bone

• The pelvis is formed by two coxal bones (right and left), along with the sacrum and coccyx.

• The coxal bone is a unique flat bone resulting from the fusion of three separate bones: ilium, pubis, and ischium.

Description of Ilium

• The ilium has a wing-like shape resembling a fan or paddle, featuring anterior, superior, and posterior borders.

• It includes external (fossa iliaca externa) and internal surfaces; important anatomical landmarks include anterior superior iliac spine (ASIS) and anterior inferior iliac spine (AIIS).

Anatomical Landmarks on Ilium

• ASIS serves as an important anatomical reference for abdominal topography; it provides insertion points for muscles such as sartorius and tensor fasciae latae.

• AIIS allows for muscle attachment of rectus femoris tendon; this muscle is part of the quadriceps group.

Muscle Attachments on Ilium

• The superior border known as the iliac crest provides attachment for three abdominal wall muscles: external oblique, internal oblique, transversus abdominis.

• Posteriorly, there are additional spines including posterior superior iliac spine (PSIS), which lacks significant detail compared to other structures.

Sciatic Notch & Related Structures

• The greater sciatic notch allows passage for several structures including piriformis muscle above it and sciatic nerve below it.

• Lesser sciatic notch permits entry back into the pelvis for pudendal artery after exiting through greater sciatic notch.

Gluteal Muscle Insertions

• On the external surface of ilium are crests that delineate zones for gluteal muscle insertions: gluteus minimus (anterior), gluteus medius (middle), gluteus maximus (posterior).

Internal View of Coxal Bone

Muscles of the Posterior Abdominal Wall

Overview of Key Muscles

• The anterior group of muscles in the posterior abdominal wall includes two primary muscles: the psoas major and the quadratus lumborum.

• The psoas major has an insertion point at the lumbar vertebrae (L1-L5), specifically at the transverse processes and intervertebral discs, as well as a portion that connects to the ilium.

• There is mention of a lesser muscle called the psoas minor, which consists of fibers that attach to the lower part of the iliac crest and share a common tendon with the iliacus muscle, terminating at the lesser trochanter.

• The only muscle inserting into the lesser trochanter of the femur is indeed identified as the iliopsoas, which is crucial for understanding its anatomical significance.