Chapter 7
Pelvic Girdle and Lower Limbs
Pelvic Girdle
• Consists of two coxae (hipbones) that
articulate with each other anteriorly and with
the sacrum posteriorly
Pelvic Girdle
• Functions:
– Supports the trunk of the body (weight is
transmitted through the girdle to the lower limbs
and then the ground)
– Provides attachments for the lower limbs
– Protects the bladder, the distal end of the large
intestine, and the internal reproductive organs
Coxae
• Each coxa develops from three parts: ilium,
ischium, and pubis
• The three parts fuse to form a depression
called the acetabulum on the lateral surface
of the hipbone
– The acetabulum
receives the head
of the femur
that
Coxae
• Ilium
– Largest and most superior of
the coxa
– Forms the prominence of the
hip
Coxae
• Ilium
– Special features:
• Iliac crest
– Margin of the prominence
• Iliac fossa
– Smooth, concave surface on
the anterior side
Coxae
• Ilium
– Special features:
• Sacroiliac joint
– Where the iliac joins the sacrum
Coxae
• Ilium
– Special features:
• Anterior superior iliac
spine
– Spine the provides
attachments for ligaments
and muscles
• Posterior superior iliac
spine
– Spine on the posterior
border
Coxae
• Ilium
– Special features:
• Greater sciatic notch
– Indentation below the
posterior superior iliac
spine through which
nerves and blood vessels
pass
Coxae
• Ischium
– Forms the lowest portion of
the coxa
– L-shaped
Coxae
• Ischium
– Special features
• Ischial tuberosity
– Angle of the ischium
– Points downward and
posteriorly
– Provides attachments
for ligaments and lower
limb muscles
– Supports the weight of
the body during sitting
Coxae
• Ischium
– Special features
• Ischial spine
– Sharp projection located
above the ischial
tuberosity, near the
junction of the iliam and
ischium
Coxae
• Pubis
– Anterior portion of the coxa
Coxae
• Pubis
– Special features:
• Symphysis pubis
– Joint between the 2 pubic bones
• Pubic arch
– Formed by the angle of the pubic bones beneath the
symphysis pubis
• Pubis
Coxae
– Special features:
• Obturator foramen
– Largest foramen in the skeleton
– Located between the pubis and ischium bones
– Covered by an obturator membrane
Greater and Lesser Pelves
• Greater pelvis (false pelvis)
– Upper part of the pelvis
– Bounded posteriorly by the lumbar vertebrae,
laterally by the flared parts of the iliac, and
anteriorly by the abdominal wall
– Helps support the abdominal organs
Greater and Lesser Pelves
• Lesser pelvis (true pelvis)
– Bounded posteriorly by the sacrum and coccyx
and laterally and anteriorly by the lower ilium,
ischium, and pubis bones
– Surrounds the cavity through which an infant
passes during the birthing process
Differences between Male and Female Pelves
• Iliac bones in females are
usually more flared, creating
broader hips
• Pelvic cavity in females is
usually wider in all diameters
than that of males
• Bones in female pelvis are
usually lighter and show less
evidence of muscle
attachments than those of
males
• http://www.innerbody.com/image_skel20/ske
l35.html
Lower Limbs
• Include femur, tibia, fibula, tarsals,
metatarsals, and phalanges
Femur
• Longest bone in the body
• Extends from the hip to the
knee
Femur
• Special features:
– Head
• Located at the proximal end
• Projects medially into the
acetabulum of the coxa
– Fovea capitis
• Pit on the head that marks the
attachment of a ligament
– Neck
• Constriction located just below
the head
Femur
• Special features
– Greater trochanter
• Large process below the head
• Provide attachments for muscles
of the lower limbs
– Lesser trochanter
• Large process below the head
• Provide attachments for muscles
of the lower limbs
Femur
• Special features
– Linea aspera
• Longitudinal crest in the middle
of the femur that serves as an
attachment for muscles
– Lateral and medial condyles
• Rounded processes at the distal
end that articulate with the tibia
– Medial and lateral epicondyles
• Projections on the distal surface
that provide attachments for
muscles
Patella
• Flat sesamoid (round) bone
• Located in a tendon that passes anteriorly
over the knee
Tibia
• Larger of the two leg bones
• Located on the medial side
• Articulates with the talus in
the ankle
• Special features:
Tibia
– Medial and lateral condyles
• Expanded proximal end
• Have concave surfaces that
articulate with the condyles of the
femur
– Tibial tuberosity
• Process on the anterior surface
that provides an attachment for
the patellar ligament
• Special features:
Tibia
– Anterior crest
• Extends downward from the
tuberosity and attaches
connective tissues in the leg
– Medial malleolus
• Expanded prominence on the
inner ankle that forms an
attachment for ligaments
Fibula
• Long, slender bone located
on the lateral side of the
tibia
Fibula
• Special features:
– Head
• Enlarged proximal end
• Articulates with the tibia
• Doesn’t enter into the knee
joint or bear any body weight
– Lateral malleolus
• Enlarged distal end
• Articulates with the ankle
• Protrudes on the lateral side
• Ankle (tarsus)
Foot
– Composed of 7 tarsal bones
– The talus (your ankle bone) articulates with the
tibia and fibula and can move freely
– The calcaneus (your heel bone) helps support the
body weight and serves as an attachment for the
muscles that move the foot
Foot
• Instep (metatarsus)
– Composed of 5 metatarsal bones (numbered 2 to
5 beginning on the medial side)
– Articulates with the tarsus
– The heads of the metatarsals at the distal end
form the ball of the foot
Foot
• The tarsals and metatarsals are bound by
ligaments to form 2 arches (longitudinal arch
and a transverse arch)
Foot
• Phalanges
– Each toe (except the big toe – which has two) has
three phalanges (a proximal, middle, and distal
phalanx)
– Align and articulate with the metatarsals