Download ANATOMY OF LOWER LIMB Lecture 1

ANATOMY OF LOWER
LIMB
Lecture 1
General Introduction
The lower limb is divided into the gluteal region, thigh,
leg, and foot on the basis of major joints, component bones,
and superficial landmarks.
Regions of the lower limb
• the gluteal region is
posterolateral and between the iliac
crest and the fold of skin (gluteal
fold) that defines the lower limit of
the buttocks.
• the thigh is between the inguinal
ligament and the knee joint and the
posterior thigh is between the
gluteal fold and the knee.
• the leg is between the knee and
ankle joint.
• the foot is distal to the ankle
joint.
The bones of the lower limb
• The bones of the gluteal region are the
pelvic bones.
• Thigh bone is the femur. it articulate with
the patella (knee cap).
Bone of leg are:
The tibia is medial in position, is large
bone, and is the weight bearing bone.
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The fibula is lateral bone, smaller than
tibia, participate in ankle, no participation in
the knee joint.
• *They articulate to each other by superior and
inferior tibiofibular joints.
• *Between these two bones there is an
interosseous membrane.
The bones of the lower limb
The bones of the foot consist of
 the seven tarsal bones,
 the metatarsals,
 the phalanges.
The ankle joint is formed by
distal end of the tibia and part of
one of the tarsal bones of the foot
(talus) with small participation of
fibula.
The ilium, ischium, and pubis form the hip bone.
They meet one another at the acetabulum.
The hip bones articulate with the sacrum at the sacroiliac joints.
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They also articulate with one another anteriorlly at the symphysis pubis.
Bones of the Gluteal Region
The ilium
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Iliac crest
Ala
Internal lip of iliac crest
Anterior superior iliac spine
Posterior superior iliac spine
Anterior inferior iliac spine
Posterior inferior iliac spine
Greater sciatic notch.
The ischium
The ischium
is L shaped, possessing an upper
thicker part, the body, and a lower
thinner part, the ramus.
The ischial spine projects from
the posterior border of the ischium and
intervenes between the greater and
lesser sciatic notches.
The ischial tuberosity forms the
posterior aspect of the lower part of
the body of the bone.
The pubis
The pubis
Divided into a body, a superior
ramus, and an inferior ramus.
The bodies of the two pubic bones
articulate with each other in the
midline anteriorlly at the symphysis
pubis;
the superior ramus joins the ilium
and ischium at the acetabulum,
the inferior ramus joins the ischial
ramus below the obturator foramen.
Obturator canal
The obturator foramen in
life is filled in by the obturator
membrane.
The obturator membrane is
a thin fibrous sheet, which almost
completely closes the obturator
foramen.
Its fibers are arranged in
interlacing bundles;
the uppermost bundle
completes the obturator canal for
the passage of the obturator
vessels and nerve.
the acetabulum
On the outer surface of the hip bone is a
deep depression, called the acetabulum, that
articulates with the almost spherical head of
the femur to form the hip joint.
The inferior margin of the acetabulum is
deficient and is marked by the acetabular
notch.
The articular surface of the acetabulum is
limited to a horseshoe-shaped area (the lunate
surface) and is covered with hyaline cartilage.
The floor of the acetabulum is nonarticular
and is called the acetabular fossa.
The Pubic Symphysis
The Pubic Symphysis is the
midline cartilaginous joint, uniting
the bodies of the left and right pubic
bones.
The cartilaginous disk is reinforced by
a series of ligaments:
1. The superior pubic ligament;
2. The inferior pubic ligament (arcuate
pubic ligament).
Arcuate = ‫مقوّ س‬
The sacrum
The sacrum is a large,
triangular bone at the base of
the spine and at the upper and back
part of the pelvic cavity.
It consists of usually five initially
unfused vertebrae which begin to
fuse between ages 16–18 years and
are usually completely fused into a
single bone by age 34.
sacroiliac joints
The sacroiliac joints are two
paired "kidney bean" or L-shaped
synovial joints.
having a small amount of
movement (2–18 degrees, that are
formed between the articular
surfaces of the sacrum and the
ilium bones.
The two sacroiliac joints move
together as a single unit and are
considered bicondylar joints
(where the two joint surfaces move
correlatively together).
Ligaments of the sacroiliac
joints
The sacroiliac joint’s stability is
maintained mainly through a
combination of only some bony
structure and very strong intrinsic and
extrinsic ligaments:
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The Anterior Sacroiliac ligament;
The Posterior Sacroiliac ligament;
The Sacrotuberous Ligament;
The Sacrospinous Ligament.
Ligaments of the sacroiliac joints
The Sacrotuberous Ligament is
situated at the lower and back part of
the pelvis and runs from the sacrum to
the tuberosity of the ischium.
Ligaments of the sacroiliac joints
The Sacrospinous Ligament is a
thin, triangular ligament attached by
its apex to the ischial spine, and
medially, by its broad base, to the
lateral margins of the sacrum
and coccyx.
Together with the sacrotuberous
ligament, it converts the greater
sciatic notch into the greater sciatic
foramen and the lesser sciatic
notch into the lesser sciatic
foramen.
The greater sciatic foramen is
bounded as follows:
• anterolaterally by the greater
sciatic notch of the illium;
• posteromedially by
the sacrotuberous ligament;
• inferiorly by the sacrospinous
ligament and the ischial spine;
• superiorly by the anterior
sacroilliac ligament.
The lesser sciatic foramen has
the following boundaries:
•Anterior: the tuberosity of the
ischium.
•Superior: the spine of the
ischium and sacrospinous
ligament.
•Posterior: the sacrotuberous
ligament.