Muscles of the Leg Flashcards
describe the skin of the leg
hair skin of intermediate thickness
describe the superficial fascia of the leg
thickness varies, absent at subcutaneous surfaces; contains superficial veins and cutaneous nerves
the deep fascia of the leg is continuous with
the deep fascia (fascia lata) of the thick and the deep fascia of the foot
what does the deep fascia of the leg completely surrounds — and fuses to
the muscles and fuses to the periosteum of the tibia and fibula at subcuatenous surfaces
what does the deep fascia form at the posterior aspect of the knee region
popliteal fascia
what does the deep surface of the deep fascia on the lateral aspect of the leg give rise to
an anterior and posterior fibular (peroneal) septa which separate the lateral compartment of the leg muscles from the anterior and posterior compartments
the posterior compartment of the deep fascia below the popliteal fossa (deep to the soleus muscle) is further divided into?
a deep and superficial compartment
what divides the posterior compartment into a deep and superficial compartment
the deep transverse fascia
all of the leg muscles are extrinsic leg muscles of the foot except for
popliteus
as a general rule, tendons passing anterior to the ankle joint are —- and tendons passing posterior are —
dorsiflexors
plantarflexors
the muscle of the leg are divided into how may compartments? what are they?
4 compartments
- anterior
- lateral
- superficial posterior
- deep posterior
what does the anterior compartment contain
- TA
- EHL
- EDL
- Fibular tertius
what does the lateral compartment contain
FL
FB
what does the superficial posterior compartment contain
- gastrocnemius
- soleus
- plantaris muscles
what does the deep posterior compartment contain
- popliteus
- FDL
- TP
- FHL
what does the popliteus muscle and its overlying deep fascia form
part of the floor of the popliteal fossa
origin of TA
Lateral condyle and upper two-thirds of the lateral surface of the shaft of the tibia.
Adjacent interosseous membrane.
Deep surface of the deep fascia
Course of TA
Tendon courses in a synovial sheath beneath the most medial portion of the superior and inferior extensor retinaculae
insertion of TA
Medial and plantar surfaces of the first cuneiform and base of the first metatarsal (first ray)
Action of TA
Dorsiflexes and inverts the foot.
Also adducts the foot slightly
course and insertion of the tendons of TA and TP form a — with the course and insertion of the tendon of FL
stirup
Origins of EHL
Middle one-half of the medial surface of the shaft of the fibula.
Adjacent interosseous membrane
Course of EHL
Tendon courses in a synovial sheath beneath the superior and inferior extensor retinaculae
Insertion of EHL
Forms the extensor hood at the first MTP, and then inserts into the dorsum of the base of the distal phalanx of the hallux
Action of EHL
Dorsiflexes the hallux at the interphalangeal and metatarsophalangeal joints; and dorsiflexes and inverts the foot
why is the relationship of the tendon of EHL to the anterior tibial artery important?
the EHL tendon crosses from the lateral to the medial side of the anterior tibial vessels and deep fibular nerve at the ankle
origin of EDL
Lateral condyle of the tibia. Head of the fibula and upper three-fourths of the medial surface of the shaft of the fibula. Adjacent interosseous membrane. Anterior fibular (peroneal) septa. Deep surface of the deep fascia
course of EDL
Tendon(s) courses in a synovial sheath (with the tendon of fibularis (peroneus) tertius) beneath the superior and inferior extensor retinaculae.
It divides into four tendons, one for each of the lesser digits.
insertion of EDL
Each of the four tendons forms an extensor hood at the MTP and at the head of a proximal phalanx divides into three slips (trifurcation).
The central slip inserts into the dorsum of the base of a middle phalanx while the two collateral slips unite at the head of a middle phalanx and insert into the dorsum of the base of a distal phalanx
action of EDL
Dorsiflexes the lesser digits at the interphalangeal and metatarsophalangeal joints; dorsiflexes the foot
what is another name for extensor hood
extensor sheath
extensor expansion
extensor retinaculum
the tendons of EDL and EHL expand at the level of
MTP to form an extensor hood
extensor hood expands from
the head of a MT to the distal aspect of the proximal phalanx
the proximal component of the hood is
the sling portion
describe the fibers of the sling portion
fibers encircle the capsule of the MTP and blend with the plantar plate, deep transverse MT ligament and the flexor sheaths
the distal component of the hood is the
wing portion
describe the fibers of the wing portion
fibers are arranged obliquely on the sides of the digit
what contributes to the extensor hood on the lesser digits
the tendons of the dorsal interossei; plantar interossei; lumbricals; and the first, second, and third tendons of EDB
what is the purpose of the extensor hood
- helps maintain the central position of the EDL tendons and the tendon of EHL
- aids in dorsiflexion of the proximal phalanx through the sling mechanism
origin of fibularis tertius
Lower one-fourth of the medial surface of the shaft of the fibula. Adjacent interosseous membrane. Anterior fibular (peroneal) septa
course of fibularis tertius
Tendon courses in a synovial sheath (with the tendon(s) of EDL) beneath the superior and inferior extensor retinaculae
insertion of fibularis tertius
Dorsum of the base of the fifth metatarsal
action of fibularis tertius
Dorsiflexes the foot; aids in eversion of the foot
fibularis tertius is often considered to be the — tendon of EDL
5th
may also be absent
origin of fibular longus
Lateral condyle of the tibia. Head and upper two thirds of the lateral surface of the shaft of the fibula. Deep surface of the deep fascia. Anterior fibular (peroneal) septa. Posterior fibular (peroneal) septa
course of fibularis longus
The tendon courses through the lateral malleolar sulcus; then deep to the superior fibular (peroneal) retinaculum; then superficial to the calcaneofibular ligament; then inferior to the fibular trochlea being deep to the inferior fibular (peroneal) retinaculum;
then to the fibular (peroneal) notch; then through the fibular (peroneal) sulcus obliquely across the plantar surface of the foot in then third layer of plantar muscles.
Tendon courses in a synovial sheath along with the tendon of fibularis (peroneus) brevis beneath the superior and inferior fibular (peroneal) retinaculae; and in its own synovial sheath in the fibular (peroneal) sulcus
insertion of fibularis longus
Lateral and plantar surfaces of the first cuneiform and base of the first metatarsal (first ray)
action of fibularis longus
Pronation and plantarflexion of the foot.
It also acts to support the transverse arch of the foot
the course and insertion of — and — form a stirrup with the course and insertion of —
TA
TP
FL
an acessory sesamoind known as —- may be located in the tendon of PL near the lateral surface of the cuboid
os peroneum
origin of FB
Lower two thirds of the lateral surface of the shaft of the fibula. Anterior fibular (peroneal) septa. Posterior fibular (peroneal) septa
course of FB
The tendon courses through the lateral malleolar sulcus (being anterior to the tendon of PL);
then deep to the superior fibular (peroneal) retinaculum;
then superficial to the calcaneofibular ligament;
then superior to the fibular trochlea being deep to the inferior fibular (peroneal) retinacula;
Tendon courses in a synovial sheath along with the tendon of fibularis (peroneus) longus beneath the superior and inferior peroneal retinaculae
insertion of FB
Tuberosity of the base of the fifth metatarsal
action of FB
Pronation and plantarflexion of the foot
the FB may avulse part of the — in an inversion injury
tuberosity of the base of the 5th MT
origin of the medial head of the gastrocnemius
Medial condyle of the femur and capsule of the knee joint
origin of the lateral head of the gastrocnemius
Lateral condyle of the femur and capsule of the knee joint
course of the gastrocnemius muscle
Muscle fibers attach to the anterior surface of a posterior aponeurosis of origin.
Aponeurosis of insertion is formed anteriorly which fuses with the aponeurosis of insertion of the soleus to form the tendo calcaneus
insertion of the gastrocnemius
By tendo calcaneus into the middle one-third of the posterior surface of the calcaneus
action of the gastrocnemius
Flexes the leg.
Plantarflexes the foot.
a sesamoid bone known as the fabella is occasionally found where
in the lateral head of the gastroc
a Haglund’s deformity is also known as
pump bump or supracalcaneal exostosis
where is Haglund’s deformity located
the posterior superior surface of the calcaneus
what causes Haglund’s deformity
- shoe gear
- overpronation
origin of the soleus muscle
Posterior surface of the head of the fibula and upper one-third of the posterior surface of the shaft of the fibula. Soleal line (popliteal line) and middle one-third of the medial border of the shaft of the tibia. Posterior fibular (peroneal) septa.
course of the soleus muscle
Muscle fibers attach to the posterior surface of a anterior aponeurosis of origin.
Aponeurosis of insertion is formed posteriorly which fuses with the aponeurosis of insertion of the gastrocnemius to form the tendo calcaneus
insertion of the soleus muscle
By tendo calcaneus into the middle one-third of the posterior surface of the calcaneus
action of the soleus muscle
Plantarflexes the foot
there is a bursa between the tendo calcaneus and the calcaneus called
retrocalcanela or subtendinosus
there is a bursa between the tendo calcaneus and the skin called
subcutaneous or adventitial
origin of plantaris muscle
Lateral condyle of the femur
course of the plantaris m.
Tendon courses obliquely between the gastrocnemius and soleus from lateral to the medial side of tendo calcaneus
insertion of the plantaris m.
Medial side of the middle one-third of the posterior surface of the calcaneus (may insert into the medial surface of the calcaneus)
action of the plantaris m.
Functions with the gastrocnemius.
Has a high density of proprioceptors and may act as a proprioceptor for larger plantarflexors
the tendon of plantaris may be referred to as
Freshman’s nerve
origin of popliteus in CKC
Posterior surface of the shaft of the tibia above the popliteal (soleal) line
origin of popliteus in OKC
Popliteal groove on the lateral epicondyle of the femur
insertion of popliteus in CKC
Popliteal groove on the lateral epicondyle of the femur
insertion of popliteus in OCK
Posterior surface of the shaft of the tibia above the popliteal (soleal) line
action of the poplitues in CKC
Unlocks (laterally rotates the femur out of the screw-home position) the knee joint at the beginning of flexion
action of popliteus in OKC
Internally (medially) rotates the tibia
the tendon of popliteus separates the lateral meniscus from
the fibular collateral lig
origin of FHL
Lower two-thirds of the posterior surface of the shaft of the fibula lateral to the crista medialis.
Lower portion of the interosseous membrane.
Posterior fibular (peroneal) septa.
Deep surface of the deep transverse fascia.
what leg muscle has the most inferior origin of all the leg muscles
FHL
course of FHL
The tendon courses through the groove on the posterior surface of the distal extremity of the tibia;
then in a synovial sheath deep to the flexor retinaculum;
then between the two tubercles on the posterior surface of the body of the talus;
then inferior to the sustentaculum tali;
then distally on the plantar surface of the foot in the second layer of muscles where it gives rise to the Knot of Henry, then into a synovial sheath within the flexor sheath of the first toe
insertion of FHL
Plantar aspect of the base of the distal phalanx of the hallux
action of FHL
Plantarflexes the hallux at the IPJ and MTP.
Plantarflexes the foot
origin of FDL
Posterior surface of the shaft of the tibia below the soleal line and medial to the vertical ridge.
Deep surface of the deep transverse fascia
course of FDL
Tendon courses posterior (behind) to the tendon of tibialis posterior in the lower leg;
then through the medial malleolar sulcus;
then in a synovial sheath deep to the flexor retinaculum; then superficial to the deltoid ligament; then distally on the plantar surface of the foot in the second layer of plantar muscles superficial (inferior, or below) to the tendon of FHL from which it receives the Knot of Henry;
it is then joined by the quadratus plantae;
then divides into four tendons, one for each lesser digit; then into a synovial sheath within the flexor sheath of a lesser digit where each tendon courses through the split in their respective tendon of FDB
insertino of FDL
Plantar surface of the base of the distal phalanges of the second, third, fourth, and fifth toes
action of FDL
Plantarflexes the lesser digits at the IPJ’s and MTP’s.
Plantarflexes the foot
why if the tendon of FDL referred to as “B-B tendon”
because it courses behind (posterior) to the tibialis posterior in the leg and below (inferior) to the FHL tendon in the foot
origin of TP
Posterior surface of the shaft of the tibia below the soleal line and lateral to the vertical ridge.
Upper two-thirds of the posterior surface of the shaft of the fibula medial to the crista medialis.
All but the distal aspect of the interosseous membrane.
Deep surface of the deep transverse fascia
course of TP
Tendon courses deep to the tendon of FDL;
then in the medial malleolar sulcus;
then in a synovial sheath deep to the flexor retinaculum;
then superficial to the deltoid ligament;
then inferior to the spring ligament
insertion of TP
Tendon divides into a main, recurrent, and plantar component:
Main: Tuberosity of the navicular and plantar surface of the first cuneiform.
Plantar: Second and third cuneiforms; cuboid; and the second, third, and fourth metatarsal bases.
Recurrent: Sustentaculum tali
action of TP
Plantarflexion and supination of the foot
function of anterior compartment leg muscles
- Dorsiflexion of the foot at toe off and the beginning of swing for toe clearance of the ground;
- To resist plantarflexion of the foot at heel strike to prevent foot slap; and
- To permit smooth loading of the forefoot.
additional function of EHL
Provide extensor stability to the first MTP during early propulsion.
additional function of EDL
- Assist the lumbricales, interossei and FDL in developing extensor rigidity of the IPJ’s of the lesser digits during early propulsion (rigid beam effect)
- Prevent excessive supination of the foot during swing.
additional function of TP
Prevent excessive supination of the foot during swing.
function of the lateral leg compartment
To assist in acceleration of ankle joint plantarflexion during propulsion
additional function of FL
- Stabilize the first ray during stance
- Aids in the transfer of body weight from the lateral to the medial side of the foot and to the opposite foot during propulsion
additional function of FB
Stabilize the lateral column during stance (Fifth metatarsal, cuboid and calcaneus).
function of the posterior leg compartment
To assist in acceleration of ankle joint plantarflexion during propulsion
additional function of gastrocnemius
Stabilize the knee and prevent hyperextension during stance
additional function of soleus
Decelerate the forward momentum of the tibia during stance
additional function of plantaris
beginning of flexion ( externally or laterally rotate the femur out of the screw home position
additional function of FHL
- Maintain stability of the hallux against the ground during propulsion
- Assist in posterior stabilization of the distal phalanx against the proximal phalanx during propulsion.
additional function of FDL
Assist the lumbricales, interossei and EDL in developing extensor rigidity of the IPJ’s of the lesser digits during propulsion (rigid beam effect)
additional function of TP
- Decelerate Subtalar joint pronation and internal leg rotation during contact
- Aids in resupination in midstance.
what are lateral and inferior boundaries of the diamond shaped fossa at the posterior aspect of the knee
lateral head of the gastrocnemius and plantaris
what are the medial and inferior boundaries of the diamond shaped fossa at the posterior aspect of the knee
medial head of the gastroc
what are the lateral and superior boundaries of the diamond shaped fossa at the posterior aspect of the knee
biceps femoris
what are the medial and superior boundaries of the diamond shaped fossa at the posterior aspect of the knee
semitendinosus and semimembranosus
the floor of the popliteal fossa is composed of
Popliteal surface of femoral shaft.
Capsule of knee joint.
Upper posterior portion of proximal extremity of tibia.
Deep transverse fascia covering popliteus
roof of the popliteal fossa is composed of
popliteal fascia
contents of the popliteal fossa
Popliteal artery and vein and their genicular branches.
Tibial and common fibular (peroneal) nerves.
Popliteal lymph nodes.
Termination of the small saphenous vein.
Fatty tissue.