Transcript document

MYOLOGY2
Department of anatomy
Luzhou medical college
Made by professor Xiao
The muscles of lower
limb
• The muscles of lower limb are divisible
according to their locations into the muscles of
hip, the muscles of thigh, the muscles of leg and
the muscles of foot.
• Ⅰ. The muscles of hip
• They arise chiefly from the outer and inner
surfaces of the pelvis,cross the hip joint and are
inserted into the proximal end of femur. Based
on their locations and functions they can be
divided into two groups.
Ⅰ). Anterior group
• 1. The iliopsoas
• It is composed of two muscles. The psoas major
is a long, thick, fusiform one that lies lateral to
the lumbar region of the vertebral column. It
arises from the transverse process, vertebral
bodies and associated intervertebral disc of L1to
L5vertebrae. The muscle descends laterally
along the brim of the pelvis and enters the thigh
by passing posterior to the inguinal ligament,
and in inserted into the lesser trochanter of
femur. The iliacus is a fan-shaped one which lies
along the lateral side of the psoas major. It
arises from the iliac fossa. Most of its fibers
attach to the side of the psoas major tendon.
• The psoas major is enclosed by a fascial sheath.
The pus of the tuberculosis of the lumbar
vertebrae may drain along this sheath into the
iliac fossa or the root of thigh.
• Actions
• It is the most powerful flexor of the thigh. If the
lower limb is fixed, it bends the vertebral column
forward and flexes the lumbar region laterally. It
also can rotate the thigh laterally.
2. The tensor fasciae latae
• It lies on the lateroanterior side of the thigh,
arises from the anterior superior iliac soine
and is enclosed within the fascia lata. Its
fibers attached to the iliotibial tract which is
inserted into the lateral condyle of the tibia.
• Actions
• Flexes the hip joint. Helps to keep the
knee extending in erect posture and
steadies the trunk on the thigh.
Ⅱ). The posterior group
• It lies chiefly in the gluteal region, so that they are also
called the gluteus muscles.
• 1. The gluteus maximus
• It is a large, thick, quadrilateral subicutaneous pad over
the ischial tuberosity when the thigh is extensed. It arises
from the dorsal portion of the iliac ala, the dorsal
surfaces of the sacrum and the coccyx, and
sacrotuberous ligament. Its fibers run downward and
laterally to insert into the iliotibial tract and the gluteal
tuberosity of the femur.
• Actions
• It is a powerful extensor of the thigh, the most powerful
lateral rotator, and an important postural muscle.
Ⅱ). The posterior group
• 2. The gluteus medius and gluteus
minimus
•
The gluteus medius is a thick, broad, fan-shaped
muscle. Most of which lies superior to the gluteal
maximusand is covered by the fascia lata.the lower one
third of the musclelies deep to the gluteus maximus.
•
The gluteus mimimus lies immediately beneath the
gluteus medius. The two muscles arise from the eaternal
surface of the iliac ala. Their fibers get togather in a short
tendon to insert into the greater trochanter of femur.
• Actions
• Abductor and rotate the.
The piriformis
It lies deep to the
gluteus medius. It
arises from the
front surface of the
sacrum, passes
out of the pelvis
through the greater
sciatic foramen,
and is inserted by
a rounded tendon
into the upper
border of the
greater trochanter.
Action: laterally
rotates the thigh.
Ⅱ. The muscles of thigh
• They are
divided into
three groups
• The
anteriorextersor
• The medialadductor
• The
posteriorflexor
groups are
separated
by the
medial,
lateral and
posterior
intermuscul
Ⅱ. The muscles of thigh
• (Ⅰ)The anterior group
• Two muscles
• The sartorius
• The quadriceps femoris
Sartorius
Arises from
Anterior
superior iliac
spine
Inserts into
Medial surface
of the of the
upper part of
the shaft of tibia
Actions
Flexes the hip
and knee joints
and medially
rotates the
flexed knee
Quadriceps femoris
Rectus femoris
Arises from
anterior superior iliac spine
Vastus medialis
Arises from
Linea aspera
Vastus lateralis
Arises from
Linea aspera
Vastus intermedius
Arises from
Anterior surface of femur
Insert into
Anterior surface and two
sides of the patella.
Actions
Flexes the hip and extersor
of the leg.
Ⅱ. The muscles of thigh
• (Ⅱ)The madial group
• Five muscles
• The pectinus
• The adductor longus
• The adductor brevis
• The gracilis
• The adductor magnus
The pectinus
It is a short, flat,
quadrangular muscle, lies
at the root of the thigh
medial to the iliopsoas
muscle
The adductor longus
It is triangular flat muscle
lying inferomedially to the
pectinus
The adductor brevis
It is somewhat triangular
muscle, and is posterior
to pectinus and adductor
longus.
The gracilis
It is a long straplikemuscle, It lies along
the medial side of the
thigh and the knee, and
is the only one the this
group to cross the knee
joint.
The adductor
magnus
It is the largest of the
adductors. This
triangular muscle is
covered by the
preceding muscle.
Origin
The muscles of
this group arise
from the surface of
the bones
surrounding the
obturator foramen.
Insert into
Most of them are
inserted into the
linea aspera with
the exception of
the gracilis which is
inserted into the
medial surface of
the upper end of
shaft of the tibia.
The adductor
magnus is
inserted into the
The adductor
magnus
is inserted into the
adductor tubercle
above the medial
epicondyle of bone
femur,called the
adductor tendinous
opening which
allows the femoral
vessels passing
through it into the
popliteal
Actions
Adduct, flex and
laterally rotate the
thigh.
Ⅱ. The the muscles of
thigh
• (Ⅲ) The posterior group
• Three muscles
• The biceps femoris
• The semitendinosus
• The semimenbranosus
•The biceps femoris
Linea aspera
Head of fibula
•The semitendinosus
Arises from
Ischial tuberosity
Inserted into
Medial surface of
the upper part of
the tibia
•The semimenbranosus
Arises from
Ischial tuberosity
Inserted into
Posteromedial
aspect of the
medial condyle of
tibia
Actions
They are the
main extensors
of thigh and
flexors of the
leg. When the
knee joint is
flexed , they
also can rotate
the leg.
Ⅱ. The muscles of leg
• They are divided into three groups
• The anterior group
•
(The tibilis anterior, extensor digitorum longus and extensor hallucis longus)
• The lateral group
•
(peroneus longus and peroneus brevis)
• The posterior group
•
•
•
•
①The superficial layer
The gastrocnemius and the soleus
②The deep layer
The tibilis posterior, flexordigitorum longus and flexor hallucis longus
Anterior group
It is located in the front of
the tibia, fibula and the
interosseous membrane.
The muscles of this goup
are mainly concered with
dorsiflexion of the ankle
joint and extension of the
toes.
Tibialis anterior
Arises from the lateral
surface of the tibia. Its
tendon passes in front of
the ankle joint to the
medial border of foot, and
is inserted into the medial
cuneiform bone and the
plantar surface of the
base of first metatarsal
bone.
Anterior group
Extensor digitorum
longus
Arises from the anterior
surface of the fibula. Its
tendon passes to dorsal
surface of the foot and
divides into four tendons.
Each tendon forms a
membranous extensor
expansion over the
dorsum of the proximal
phlanx of the 2nd to 5th
toes.
Anterior group
Extensor hallucis longus
It lies between above two
muscles. It arises from the
medial surface of the fibula
and interosseous membrane.
Its tendon passes to dorsal
surface of the foot and is
inserted into the dorsal surface
of the base of the distal phlanx
of the big toe.
Actions
Dorsiflex the ankle joint. In
adition, the tibialis anterior can
invert the foot(the sole of the
foot faces medially), the
extensor hallucis longus
extends the big toe, and the
extensor digitorum longus
extends the other toes.
Lateral group
It lies on the laterla side of
the fibula and consists of
two muscles.
The peroneus
longus
It arises from the upper
part of the laterla surface
of the shaft of fibula. Its
tendon can easily be felt
and usually observed
proximal and posterior to
the lateral malleolus.
The peroneus
brevis
It lies deep to the peroneus
longus. It arises from the
shaft of fibula below its
partner.
The tendons of these two peroneus muscles pass behind the lateral malleolus and
separate from each otheron the laterla side of the calcaneus bone. The tendon of
peroneus brevis is inserted into the tuberosity of the 5th metatarsal bone. The tendon
of the peroneus longus crosses the sole of the foot obliquely to insert into the plantar
surface of the base of the first metatarsal bone and the medial cuneiform bone.
Actions
Acting together, they plantar-flex and invert the ankle joint. The peroneus longus with
the tibialis anterior helps to maintain the tranverse and laterla longitudinal arches of
the foot.
Posterior group
They are concerned
with plantar-flexion of
the ankle joint and
flexion of the toes,
and divided into two
layers.
Superficial layer
Gastrocnemius
Soleus
Plantaris
Deep layer
Flexor Digitorum
longus
Tibialis posterior
Flexor hallucis longus
Posterior group
Superficial layer
Gastrocnemius
It is the most
superficial one. It has
two heads of origin
which arise from the
medial and lateral
condyles of the femur
and tibia respectively.
The two heads unite
together at the inferior
margin of the popliteal
fossa. At the level of
the middle of the leg,
muscle becomes the
stout tendo calcaneus.
Posterior group
The soleus
It lies immediately deep to
the gastrocnemius. It arises
from the upper part of the
posterior surfaces of the tibia
and fibula. Inferiorly, its
muscle fibers become a
tendon that joints to the
tendo calcaneus.
The tendo calcanneus
(Tendo Achilles)
It is a common tendon of the
gastrocnemius and soleus. It
is the thickest and strongest
tendon in the body. It is
inserted into the lower part of
the posterior surface of the
calcaneus bone.
Posterior group
The tendo calcanneus
(Tendo Achilles)
Actions
Plantar-flex the ankle joint
(in walking and dancing)
Standies leg on foot during
standing. The
gastrocnemius also can
flex the knee joint.
Posterior group
The deep layer
It consists of three
muscles which lie deep
to the triceps surae.
Their tendons pass
behind the medial
malleollus.
The flexor digitorum
longus
The tibialis posterior
Flexor hallucis
longus
Posterior group
The deep layer
The flexor digitorum
longus
It lies medially and is
closely attached to
the tibia. Its tendon
runs inferiorly and
passes behind the
medial malleolus. In
the middle of the
sole it divides into
four tendons to
insert into the base
of the distal
phalanges of the
lateral four toes.
Posterior group
The deep layer
The tibialis posterior
It lies laterally to the
flexor digitorum longus.
It arises from the tibia,
fibula and posterior
surface of the
interosseous membrane.
Its tendon passes behind
the medial side of the
sole. It is inserted into
the navicular,
intermediate and lateral
cuneiforms, and the
bases of the 2nd, 3rd
and 4th metartarsals.
Posterior group
The deep layer
The flexor hallucis longus
It is the largest of the thee
deep muscles. It lies laterally
to the tibialis posterior and
arieses from the posterior
surface of the fibula. Its tendon
passes behind the medial
malleolus, then crosses deep
to the tendon of the flexor
digitorum longus in the sole of
the foot. Finally, it is inserted
into the base of the diatal
phalanx of the big toe.
Actions: plantar-flexex the
ankle joint and flexex the big
toe at all joints.
The muscles of the foot
•
They are the extensor digitorum brevis and
the extensor hallucis brevis on the dorsum.
•
The muscles of the sole can be divided like
the hand into medial, lateral and intermediate
three groups.
• Actions
•
The muscles of the sole of the foot are
individually of little important, but collectively
they are significant in posture and locomotion,
and they strongly support the arches of the foot
during movement.