Transcript 23-Back of the leg

Back of the leg
By
Prof. Saeed Abuel Makarem
Muscles of the back of the leg
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It is divided into
2 groups:
Superficial: 3 muscles,
Gastrocnemius.
Plantaris.
Soleus.
Deep: 4 muscles,
Popliteus.
Flexor digitorum longus.
Flexor hallucis longus.
Tibialis posterior.
 Origin: 2 heads
 Med: popliteal surface of
the femur above medial
condyle.
 Lat: lateral aspect of
lateral condyle of femur.
 Insertion: through the
tendo calcaneus to post
surface of calcaneus.
 Nerve: Tibial nerve.
 Action:
 Flexion of knee joint
 Planter flexion of the foot.
Gastrocnemius
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Small fusiform muscle.
May be absent or doubled
Homologues to palmaris longus
Origin: lateral supracondylar
ridge of the femur.
Insertion: long ribbon- like
tendon descends between
Gastrocnemius & soleus.
then on medial side of tendo
Achillesto t he back of the
calcaneus.
Nerve: Tibial nerve.
Action: assists in
Flexion of the knee.
Planter flexion of the foot.
Plantaris
 It is a broad flat muscle
 It forms the main bulk of the
calf.
 Origin: inverted V-shaped from
soleal line of tibia, upper ¼th of
back of the fibula & fibrous arch
between tibia and fibula.
 Insertion: tendo calcaneus
 Nerve: Tibial nerve.
 Action:
 Planter flexion of ankle.
 Main forward propulsive force
in walking & running with
Gastrocnemius & plantaris
Soleus
Deep Group
• Origin: lateral surface of lateral
condyle of the femur
• It is intra capsular, it takes partial
origin from the lateral semilunar
cartilage.
• Insertion: post. surface of the tibia
above the soleal line.
• Nerve: Tibial nerve.
• Action:
• Unlocking of the knee joint
• Flexion of the knee.
• NB. tendon of popliteus separates
between lateral meniscus and lateral
collateral ligament of the knee
Popliteus
• Origin: medial part of back of
the tibia below the soleal line.
• Insertion: terminal phalanges
of lateral four toes.
• Each slip pierces the tendon of
flexor digitorum brevis of the
sole.
• Nerve: Tibial nerve
• Action:
• Planter flexion of the terminal
phalanx of the lateral 4 toes.
• Assists in planter flexion of the
foot
Flexor digitorum
longus
• Origin: lower 2/3rd of the
posterior surface of the fibula
• Insertion: Base of the distal
phalanx of the big toe.
• Nerve: Tibial nerve.
• Action: Planter flexion of the
distal phalanx of big toe
• Assists in planter flexion of
the foot.
• Maintenance of medial
longitudinal arch of the foot.
Flexor hallucis longus
TIBIALIS POSTERIOR
• Origin:
• Back of interosseous membrane.
• Back of tibia lateral to vertical line
• Back of fibula medial to medial crest
• Insertion:
• All tarsus except talus.
• The main insertion into tuberosity of the
navicular bone.
• It is also inserted into the base of 2nd,3rd& 4th
metatarsal bones.
• Nerve: Tibial nerve
• Action:
• Planter flexion
• Inversion
• Maintain the medial longitudinal arch.
Posterior tibial artery
 One of the two terminal
branches of popliteal artery
Begins at level of the distal
border of popliteus muscle
Passes downward deep to
Gastrocnemius & soleus
It descends on posterior
surface of tibialis posterior
Its lower part lies on back
of tibia covered by skin &
fascia
It passes behind the medial
malleolus to the sole
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Tome: Tibialis posterior
Does: Flexor digitorum longus
A: Posterior tibial artery
V: Posterior tibial vein
N: Posterior tibial nerve
Hat: Flexor hallucis longus
• Branches of posterior
tibial artery (PTA):
• 1- Peroneal artery:
• Arises close to the origin of
PTA.
• Gives nutrient artery to the
fibula & descends behind it.
• Gives muscular branches
• Shares in anastomosis around
the ankle
• 2- Muscular branches
• 3- Nutrient artery to tibia
• 4-Medial planter artery
• 5- Lateral planter artery
• Larger of the 2 terminal branches of
sciatic nerve in the lower 1/3 of back
of thigh
• It bisects the popliteal fossa
• It passes deep to the Gastrocnemius
and soleus
• It lies on posterior surface of tibialis
posterior
• It accompanies the posterior tibial
artery.
• It passes behind the medial
malleolus to reach the sole
• Branches:
• Muscular branches.
• Medial calcaneal branch to
• Articular to ankle joint
• Medial & lateral planter nerves
Tibial Nerve
Prof. Saeed Abuel Makarem
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Sciatic Nerve Injury
• The sciatic nerve (L4 and 5 and S1, 2, & 3)
curves laterally and downward through the
gluteal region.
• It leaves the pelvis through the greater sciatic
foramen below the piriformis.
• situated at first midway between the post.
superior iliac spine and the ischial tuberosity.
• Then, it lies midway between the tip of the
greater trochanter and the ischial tuberosity.
• Then it passes downward in the midline on the
posterior aspect of the thigh and divides into
the common peroneal and tibial nerves, at a
variable site above the popliteal fossa.
Prof. Saeed Abuel Makarem
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Trauma
The sciatic nerve is sometimes
injured by:
• penetrating wounds,
• fractures of the pelvis, or
• dislocations of the hip joint.
Prof. Saeed Abuel Makarem
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• The sciatic nerve is most frequently injured
by…?
- badly placed
intramuscular injections
in the gluteal region.
• To avoid this injury, injections into the
gluteus maximus or the gluteus medius
should be made…
• ….well forward on the upper outer
quadrant of the buttock.
• Most nerve lesions are incomplete, and in
90% of injuries, the common peroneal
part of the nerve is the most affected.
Why?
- The common peroneal nerve fibers lie
most superficial in the sciatic nerve.
Prof. Saeed Abuel Makarem
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The following clinical features are
present:
Motor:
• The hamstring muscles are
paralyzed, but weak flexion of the
knee is possible. Why?
- because of the action of the
sartorius (femoral nerve) and
gracilis (obturator nerve).
• All the muscles below the knee are
paralyzed, and the weight of the foot
causes it to assume the plantarflexed position, or foot drop.
Prof. Saeed Abuel Makarem
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Sensory:
• Sensation is lost below
the knee, except for a
narrow area down the
medial side of the lower
part of the leg and along
the medial border of the
foot as far as the ball of
the big toe, which is
supplied by the
saphenous nerve
(femoral nerve).
Prof. Saeed Abuel Makarem
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Sciatica
• Sciatica describes the
condition in which
patients have pain along
the sensory distribution
of the sciatic nerve.
• Thus the pain is
experienced in the
posterior aspect of the
thigh, the posterior and
lateral sides of the leg,
and the lateral part of
the foot.
Prof. Saeed Abuel Makarem
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Sciatica can be caused by:
• prolapse of an intervertebral disc, with
pressure on one or more roots of the lower
lumbar and sacral spinal nerves,
• pressure on the sacral plexus or sciatic nerve
by an intrapelvic tumor, or
• inflammation of the sciatic nerve or its
terminal branches.
Prof. Saeed Abuel Makarem
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