review Flashcards
Inversion of the foot involves which of the following:
a. Peroneus Longus
b. Sub talar joint
c. Ankle joint
d. Metatarso phalangeal joint
e. Flexor digitorum brevis
(B) Sub Talar Joint
Let’s break down the action of inversion of the foot:
* Bony Bodies: Sub-talar joint formed by the articulation between the talus and calcaneus bone.
o Note the slight disparity between the anatomical and clinical sub talar joint: the anatomical sub-talar joint occurs where the talus rests on and articulates with the calcaneus while the clinical sub-talar joint refers to the compound functional joint which consists of both the anatomical sub-talar joint and the talocalcaneal part of the talocalcaneonavicular joint. The disparity is because the two parts of the sub-talar joint, by its clinical definition, cannot function independently and moves in tandem during eversion and inversion of the foot.
However, to simplify things, one can just refer to the sub-talar joint as the joint where most of the eversion and inversion occurs, along an oblique axis.
o Also important to note is that the ankle joint, also known as the talo-crural joint, is a hinge joint which allows a slight degree of rotation from side-to-side. So it DOES NOT participate in eversion and inversion of the foot.
* Muscles: Inversion of the foot is primarily carried out by the tibialis anterior and tibialis posterior muscles, also assisted by the flexor hallucis longus and digitorum muscles.
o Eversion of the foot involves the fibularis (peroneus) longus, brevis and tertius muscles
Normal venous flow in the lower limb is:
a. Mainly through the long and short saphenous vein
b. From deep veins to superficial vein
c. Assisted by inactivity of calf muscle
d. Mainly deep veins
e. Long saphenous to popliteal vein
- (D) Mainly Deep Veins
Examining each option,
a. Normal venous flow is not via the two superficial veins (long and short saphenous veins) but rather carried back to the common iliac vein via the deep veins: the anterior and posterior tibial veins, the fibular vein, popliteal vein and certainly the femoral vein.
b. Normal venous flow is from the superficial veins to the deep veins. Venous blood flows from the superficial veins to the deep veins via perforating veins which penetrates the deep fascia. It is important to keep in mind that the perforating veins
* Contain valves which only allows unidirectional venous blood flow from the superficial veins to the deep veins.
* Pass through the deep fascia at an oblique angle so that when muscles contract and the pressure increases inside the deep fascia, the perforating veins are compressed and venous blood does not flow from the deep to the superficial veins.
c. The musculovenous pump is an essential mechanism in assisting the return of venous blood from the lower limb back towards the heart via the inferior vena cava against the pull of gravity. As the muscles contract, the veins are compressed and venous blood is pushed upwards against gravity. The veins have valves which prevent the backflow of blood due to gravity.
This is clinically relevant because inactivity of the soleal (calf) muscles can potentially result in deep vein thrombosis (economy class syndrome), which predisposes these people to pulmonary embolism. This explains why patients who are required to be hospitalize for long periods of time are equipped with an artificial pump to simulate the musculovenous pump, and why economy class flyers are encouraged to stretch every now and then to avoid as much as possible venous stasis.
d. As mentioned in option A, normal venous flow in the lower limb is conducted via the deep veins including the fibular vein, the posterior and anterior tibial veins, popliteal vein and the femoral vein.
e. The long saphenous vein originates from the fusion of the dorsal venous arch with the dorsal vein of the big toe, ascends anterior to the medial malleolus and passes posterior to the medial condyle of the femur. It eventually traverses the saphenous opening in the fascia lata and drains into the femoral vein. *The short saphenous vein drains into the popliteal vein.
For stability in the hip joint, the most important ligament is the:
a. Ischiofemoral ligament
b. Iliofemoral ligament
c. Pubofemoral ligament
d. Ligament of head of femur
e. Transverse acetabular ligament
B
The following statement regarding the hamstring muscles are true except:
a. The long head of biceps femoris originates from the ischial tuberosity
b. The semitendinosus is inserted into the head of fibula
c. The hamstring muscles flex at the knee joint
d. The hamstring muscles extend at hip joint
e. The tibial portion of the sciatic nerve innervates the hamstring muscles
(D) The semitendinosus is inserted into the head of the fibula
Examining each statement,
a. The long head of the biceps femoris originates from the ischial tuberosity while the short head originates from the linea aspera, and lateral supracondylar line. The biceps femoris muscle inserts into the lateral side of the fibula, the two heads split by the fibular collateral ligament of the knee.
b. The semitendinosus muscle originates from the ischial tuberosity as well and inserts into the medial surface of the superoanterior aspect of the tibia.
c. The hamstring muscles consist of three muscles, namely the semitendinosus, semimembranosus and the biceps femoris muscles. When we consider their origin and insertion
* Semitendinosus: Originates from the ischial tuberosity and inserts into the medial, superoanterior aspect of the tibia
* Semimembranosus: Originates from the ischial tuberosity and inserts into posterior part of the medial condyle of the tibia
* Biceps femoris: Originates from [Long head] ischial tuberosity and [Short head] linea aspera and lateral supracondylar line, and inserts into the lateral aspect of the fibula
It is clear that the hamstring muscles flex the knee join because they pass posterior the knee joint.
d. Considering their origins and insertions once again, it is clear that the hamstring muscles extend at the hip joint because they pass posterior to the hip joint.
e. The hamstring muscles are indeed innervated by the tibial division of the sciatic nerve (L5, S1, S2) except for the short head of biceps femoris, which is innervated by the common fibular division of the sciatic nerve (L5, S1, S2).
The menisci are made of ….
fibrocartilage
When a patient stands on the left foot and his right pelvis tilts downward, there is a weakness of the
a. Left Gluteus Maximus
b. Right Gluteus Maximus
c. Right Gluteus Medius and Minimus
d. Left Gluteus Medius and Minimus
e. Both obturator externus muscles
D.
Recall that the gluteus medius and minimus muscle are abductors and medial rotators of the hip joint while the gluteus maximus is an extensor and lateral rotator of the hip joint.
Which of these bones does not form the medial arch of the foot?
a. Lateral cuneiform
b. Cuboid
c. 3rd metaltarsal
d. Talus
e. Calcaneum
B
This part of the quadriceps femoris acts on both the knee and the hip joint
a. Vastus medius
b. vastus intermedius
c. vastus lateralis
d. rectus femoris
e. Sartorius
D
The femoral nerve supplies muscles which act on
a. Hip joint only
b. hip and knee joint
c. knee joint only
d. knee and ankle joint
e. ankle joint only
B
The femoral nerve is a terminal branch of the lumbosacral plexus receiving nerve fibers from the anterior rami of the L2, L3 and L4 spinal segments. It mainly supplies the anterior (extensor) compartment of the thigh, namely the quadriceps femoris muscle and the sartorius muscle. Other muscles which are supplied by the femoral nerve include the pectineus and iliacus muscles.
Amongst the muscles named, we may broadly classify them into three categories:
* Act only on the hip joint – iliacus, pectineus
* Act only on the knee joint – vasti medialis, intermedius and lateralis
* Act on both hip and knee joint – sartorius and rectus femoris
Hence, the femoral nerve supplies muscles which act on both hip and knee joints.
In the popliteal fossa, the popliteal vein is deep/superficial to the tibial nerve.
deep
Which of the following is not a content of the femoral triangle?
a. Femoral artery
b. Femoral vein
c. Femoral nerve
d. Obturator nerve
e. Deep inguinal lymph nodes
(D) Obturator Nerve
The femoral triangle is bounded superiorly by the inguinal ligament, laterally by the sartorius muscle, and medially by the adductor longus muscle. The floor of the femoral triangle is formed (from lateral to medial) by the iliacus, psoas major and the pectineus muscles; overlying each is (in order) femoral nerve, artery and vein.
Important contents of The femoral triangle include:
* Femoral nerve, a branch of the lumbosacral plexus
* Femoral artery, continuation of the external iliac artery
* Femoral vein, continuation of the popliteal vein
* Deep inguinal lymph nodes present in the femoral canal
*Recall that the femoral artery and vein are enclosed within the femoral sheath but the femoral nerve is not enclosed within because it passes through the muscular compartment. The femoral sheath also forms the femoral canal just medial to the femoral vein.
In the popliteal fossa,
a. The popliteal artery is deeper than the tibial nerve
b. The long saphenous vein drains into the popliteal vein
c. Popliteus is innervated by the common peroneal nerve
d. The popliteal vein is a continuation of of the femoral vein
e. Can’t remember :/
a. In the popliteal fossa, the popliteal artery is the deepest of the neurovasculature. Superficial to it is the popliteal vein and then the tibial nerve.
Which of the following lowers the tendency for dislocation of the patella.
a. Medial meniscus
b. Anterior cruciate ligament
c. Vastus intermedius
d. Lateral collateral ligament
e. Vastus medius
E. To resist lateral dislocation of the patella, the lateral pull by the [other heads of the] quadriceps femoris muscle is resisted by the strong, more horizontal and medial pull of the vastus medialis on the medial aspect of the thigh.
The muscles of the anterior compartment of the leg are innervated by.
a. femoral nerve
b. obturator nerve
c. saphenous nerve
d. tibial nerve
e. deep peroneal nerve
E) Deep peroneal nerve
The deep fibular (peroneal) nerve originates from the common fibular nerve after its bifurcation near the neck of the fibula, carrying nerve fibers from the ventral rami of L4, L5 and S1 spinal segments. The deep fibular nerve has both sensory and motor innervation:
* Motor innervation:
o Muscles of the anterior compartment: tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius. *All these muscles dorsiflex the foot, and depending on the course of their tendons, participate in eversion and inversion of the foot
o Short intrinsic muscles of the dorsum of the foot: extensor hallucis brevis and extensor digitorum brevis
* Sensory innervation – the skin over a small area between the big toe and the second toe, also known as the first interdigital cleft
Which of the following does not contribute to the stability of the ankle joint.
a. Dorsiflexion
b. Plantarflexion
c. Shape of talus
d. Talocalcaneum ligament
e. Deltoid ligament
B
The medial malleolus grips the talus tightly during the movements of the joint. However, notice that the anterior part of the articular surface of the talus is much wider than the posterior part. So during dorsiflexion, when the wider anterior part articulates with the medial malleolus, the grip on the talus is much tighter and the stability of the ankle joint is increased. This is in contrast to plantarflexion, when the much narrower part of the talus is in articulation with the tibia. The loose grip on the talus by the medial malleolus, though allowing a wider range of action when the foot is plantarflexed, compromises the stability of the ankle joint.
Inversion of the foot involves
a. fibularis longus
b. ankle joint
c. metatarsophalangeal joint
d. subtalar joint
e. FDB
D. one can just refer to the sub-talar joint as the joint where most of the eversion and inversion occurs, along an oblique axis.
Long saphenous vein
a. begins at the lateral dorsal venous arch
b. passes posterior to the medial malleolus
c. joins short saphenous vein
d. accompanied by saphenous nerve
e. carries most blood from LL
D.
*With regards to option E, recall that majority of the venous blood in the lower limb is drained by the deep veins of the lower limb and not the superficial veins. Some of the deep veins include the posterior and anterior tibial vein, the popliteal vein and naturally the femoral vein. Blood from the superficial veins are drained into the deep veins via perforating veins.
In the popliteal fossa:
a. Popliteal artery lies between the popliteal vein and the tibial nerve
b. Popliteal vein lies deep to popliteus
c. The tibial nerve is the most superficial to the popliteal vein
d. Floor is formed by gastrocnemius
e. Biceps femoris forms its medial border
C.
a. The popliteal artery is the deepest of the neurovasculature present in the popliteal fossa. Superficial to it are the popliteal vein, and then the tibial nerve. This makes sense because the arterial vessels are usually found in the deep compartments while the veins are found in the more superficial layers. The superficial nerve is in this case is atypical since most nerves tend to run in the deep compartment as well along with the arteries.
b. The popliteus is a small triangular piece of muscle which forms the inferior floor of the popliteal fossa. With that in mind, the popliteal vein lies superficial to the popliteus muscle. In between the two structures lies the popliteal artery.
c. The tibial nerve is the most superficial of neurovasculature in the popliteal fossa, as described in option a.
d. The floor of the popliteal fossa is formed by the popliteal surface of the femur, the joint capsule of the knee and the popliteus muscle. The lateral and medial gastrocnemius muscles form the inferior border of the popliteal fossa.
e. As for the superior borders, the lateral border is formed by the biceps femoris muscle while the medial border is formed by the semimembranosus muscle.
All of the following help in supporting the medial longitudinal arch of the foot except
a. Sustenaculum tali
b. Plantar aponeurosis
c. Tibialis anterior
d. Peroneus brevis
e. Spring ligament
D.
Which of the following joints is NOT involved in inversion and eversion of the foot?
a. Talocalcaneonavicular joint
b. Calcaneocuboid joint
c. Transverse tarsal joint
d. Ankle joint
e. Subtalar joint
D. Recall that the ankle joint (also known as the talo-crural joint) is an articulation between the superior articular surface of the talus and the inferior articular surface of the tibia, the medial malleolus of the tibia and the lateral malleolus of the fibula. The ankle joint is an atypical hinge joint, which allows primarily dorsiflexion and plantarflexion, and some degrees of rotation.
Inversion and eversion of the foot DOES NOT involve the ankle joint. Inversion and eversion primarily takes place at the subtalar joint and may likely involve the joints distal to it like the calcaneocuboid joint.
The superficial fibular (peroneal) nerve innervates muscles that
a. Extend thigh and leg
b. Flex thigh and leg
c. Flex leg and foot
d. Dorsiflex and invert foot
e. Plantarflex and evert foot
E
A fall from a height that damages the lateral longitudinal arch, is most likely to injure which of the following bones?
a. Talus
b. Navicular
c. Lateral Cuneiform
d. Cuboid
e. First metatarsal
D
While the question puts it into a clinical scenario, do note that it is simply a question of the bones which form the lateral longitudinal arch.
A stab wound involving the adductor (subsartorial) canal would most likely affect which of the following?
a. Obturator nerve
b. Saphenous nerve
c. Great saphenous vein
d. Profunda femoris
e. First perforating artery
B.
A patient has difficulty walking. On examination, there is weakness in dorsiflexion and inversion of the foot. The most likely muscle to be affected is
a. Peroneus Longus
b. Gastrocnemius
c. Tibialis Anterior
d. Tibialis Posterior
e. Soleus
C.
- A doctor palpating dorsalis pedis is determining blood flow from
a. Anterior tibial artery
b. Posterior tibial artery
c. Medial plantar artery
d. Lateral plantar artery
e. Genicular artery
A.
When an ankle tendon jerk is elicited, the least likely event is
a. Plantarflexion of foot
b. A stretching of muscle spindle in triceps surae
c. Efferent impuses travelling in tibial nerve
d. Activation of ventral horn cells
e. Participation of interneurons
E.
Unlike the knee jerk reflex, the ankle jerk reflex is a monosynaptic reflex. That means that eliciting the ankle jerk reflex DOES NOT involve the participation of the interneurons, which send inhibitory signals to the antagonistic muscle.
When standing straight with both feet on the ground, forward tilting of the body will cause the centre of gravity to move forwards. This can be countered by the action of:
a. Quadratus femoris
b. Psoas major
c. Gluteus maximus
d. Triceps surae
e. Hamstrings
D.
So, in order to counter the dorsiflexion of the ankle joint (beyond a point when one just falls forward, the triceps surae muscle contracts to carry out plantarflexion of the ankle joint.
In children, the head of the femur is also supplied by:
a. External iliac artery
b. Popliteal artery
c. Superior gluteal artery
d. Inferior gluteal artery
e. Obturator artery
E
The doctor examines a soldier with flat foot and finds that the head of the talus does not have its normal support due to the stretching of a ligament, which is MOST LIKELY to be the
a. Calcaneocuboid (short plantar) ligament
b. Calcaneofibular ligament
c. Calcaneonavicular (spring) ligament
d. Talofibular ligament
e. Deltoid ligament
C
* Calcaneonavicular (spring) ligament – the spring ligament helps to support the head of the talus and plays important roles in the transfer of weight from the talus and in maintaining the longitudinal arch of the foot, of which it is the keystone
The posterior cruciate ligament of a football player is torn. It
a. Inserts at tibial tuberosity
b. Inserts at adductor tubercle
c. Prevents anterior displacement of femur on fixed tibia
d. Prevents hyperextension of knee
e. Is intracapsular and intrasynovial
C
E is wrong because The posterior cruciate ligament is found deep in the knee joint and is indeed intracapsular – found within the fibrous capsule of the knee – but it is extrasynovial. Both the anterior and posterior cruciate ligaments are isolated from the synovial cavity as synovial membrane lines the exterior of the ligament.
The skin of the dorsum of the foot is mainly supplied by the
a. Obturator nerve
b. Saphenous nerve
c. Sural nerve
d. Tibial nerve
e. Superficial peroneal nerve
E.
Medial rotation of the tibia at the knee joint
a. is possible in the fully extended position
b. is a passive phenomenon during locking in a stable position
c. may be caused by the semimembranosus muscle
d. is a sign of injury to the lateral collateral ligament
e. is typical of movements at a hinge joint
C.
a. So, the only possible movement in the fully extended position is the lateral rotation of the tibia on the fixed femur (or the medial rotation of the femur on the fixed tibia).
c. The semimembranosus originates from the ischial tuberosity and inserts into the posterior part of the medial condyle of the tibia. Refer to the diagram to the right for more information. Now, try to visualize that the muscle contracts. It is now easy to see that the semimembranosus can extend the hip joint (together with the gluteus maximus muscle) and flex the leg. At the same time, one other possible motion when the leg is completely extended is the medial rotation of the tibia on the femur.
Compression of the nerve emerging between L4 and L5 vertebrae is likely to cause all of the following except:
a. Weakness of plantarflexion
b. “Difficulty extending at the knee joint”
c. “Numbness over the sole”
d. A weak ankle jerk
e. A foot drop
- (A) Weakness of Plantarflexion / (D) Weak ankle jerk
First, one must understand that the nerve emerging between the L4 and L5 vertebrae is the L4 spinal nerve. Compression of the L4 spinal nerve is commonly caused by rupture or damage to the intervertebral disc; a condition known as ‘slipped disc’.
Examining the options,
a. Weakness of plantarflexion is unlikely because plantarflexion is primarily carried out by the triceps surae muscle which derive its segmental innervation from S1 and S2 spinal nerves via the tibial nerve. So, a lesion of the L4 spinal nerve is unlikely to impair plantarflexion of the foot.
b. The chief extensor of the leg, the quadriceps femoris muscle, is innervated by the femoral nerve, and the main segmental innervation is derived from the L3 and L4 spinal nerves. So, a lesion at the level of L4 would also weaken or paralyze the quadriceps femoris muscle, making it difficult for patients to extend at the knee joint.
c. Refer to the dermatome mapping. The L4 dermatome encompasses the anteromedial aspect of the leg, the dorsal and plantar aspect of the medial first digit of the foot. Undeniably, the sensation would be impaired but numbness would not be observed over the entire sole. This is due to alternative innervation by L5 and S1 spinal nerve as well.
d. Ankle jerk is the classic test used to test the integrity of the S1 nerve root. Therefore, a compression of the L4 nerve root will NOT affect the ankle jerk.
e. A foot drop is likely because the main segmental innervation of the extensors (dorsiflexors) of the foot is derived from the L4 spinal nerve (through the deep fibular nerve). Hence, a lesion of the L4 spinal nerve will result in paralysis of the extensors of the foot, resulting in a foot drop due to gravity and unopposed action of the flexors of the foot (triceps surae, flexor hallucis and digitorum longus).
Cancerous lymph nodes may envelope and destroy adjacent structures as it grows. A physician might suspect involvement of lymph nodes in the anterolateral pelvis because one of the following movements in a patient is weakened or lost. Which movement is it?
a. lateral rotation of the thigh
b. adduction of the thigh
c. extension of the knee
d. abduction of the thigh
e. flexion of the thigh
C. Lymph nodes in the anterolateral pelvis are usually found along the common and external iliac vessels. In the context of the question, it is extremely worrying when we consider the femoral canal (where the deep inguinal lymph nodes reside). If these lymph nodes were to become malignant and destroy the adjacent structures, the structures in the femoral triangle can be adversely affected. These include the femoral artery, vein and nerve.
So, with that understanding, it is now clear to see that the movement that the clinician was worried would be compromised is the extension of the knee.
60-year-old man present dull hip pain for past 4 months. Radiograph reveal 9 x 7cm mass involving right ischium of pelvis. Mass has irregular borders and there are extensive areas of bone destruction along with some scattered calcification. Grossly, mass has blueish-white cut surface. Which is the most likely diagnosis?
A) chondrosarcoma.
B) osteosarcoma.
C) Ewing sarcoma.
D) fibrous dysplasia.
E) osteoblastoma
A
A male patient presents with a rapidly enlarging right chest wall bone mass. The biopsy shows a small round cell tumor with rosette formation and a diffuse membranous CD99 expression. No osteoid was found. Which of the following is most likely true?
A) the tumor is an osteosarcoma (small cell)
B) the tumor is likely to have a chromosomal translocation (t11:22)
C) n-myc proliferation is of important prognostic value
D) the patient is likely to be an elderly man
E) unlike osteosarcoma, the tumor is resistant to chemotherapy
B
A 13-year-old boy presents with a left distal femoral bone tumour, centred in the metaphysis. An intraoperative frozen section is done for the bone tumour. The frozen section diagnosis reads “High-grade malignant spindle cell lesion with osteoid formation and many giant cells.” The MOST LIKELY diagnosis is:
A. Osteosarcoma
B. Giant cell reparative granuloma
C. Giant cell tumour
D. Chondroblastoma
E. Juvenile fibrosarcoma
A
The most powerful extensor of the thigh is the:
a. gluteus maximus
b. psoas major
c. iliacus
d. obturator externus
e. piriformis
A.
Which of the following is found superficially immediately anterior to the medial malleolus?
a. small saphenous vein
b. greater saphenous vein
c. dorsalis pedis artery
d. arcuate artery
e. anterior tibial artery
B.
The long (or great) saphenous vein first arises from the union of the medial aspect of the dorsal venous arch and the dorsal vein of the big toe and passes anterior to the medial malleolus.
* The small saphenous vein passes posterior to the lateral malleolus of the fibula.
* The dorsalis pedis artery is palpable just lateral to the tendon of the extensor hallucis longus muscle, on the dorsum of the foot. This is clinically relevant because clinicians often measure the dorsalis pedis artery pulse to assess peripheral vascular disease.
* The anterior tibial artery can be palpated anterior to the ankle joint, midway between the medial and lateral malleoli.
A man was hit in the leg by a baseball bat producing a fracture of the head and neck of the fibula and damaging a major nerve to the leg. Physical findings that would be found is/are:
a. inability to plantar flex his foot
b. inability to dorsiflex his foot
c. the foot would be everted
d. flexion of the leg is lost
e. extension of the leg is lost
B
Which of the following is NOT a lateral rotator of the hip?
a. piriformis
b. gluteus medius
c. obturator internus
d. obturator externus
e. quadratus femoris
B - Primarily abduction and medial rotation of the thigh
As the sciatic nerve passes vertically from the gluteal region into the thigh, it runs midway between the ischial tuberosity and the:
a. iliac crest
b. symphysis pubis
c. greater trochanter
d. ischial ramus
e. lesser trochanter
C.
The sciatic nerve, when entering the thigh from the gluteal region, runs approximately midway between the ischial tuberosity and the greater trochanter. This is clinically relevant because this landmark helps surgeons and clinicians to identify the approximate location of the sciatic nerve. The sciatic nerve is the largest mixed nerve in the body and is often prone to injury due to clinical procedures.
- A quick way to check the function a one of the nerves of the leg is to pinch the skin between the big toe and 2nd toe. Which nerve are you checking?
a. deep peroneal
b. lateral plantar
c. lateral plantar
d. saphenous
e. superficial peroneal
A
Which muscle is NOT a flexor of the thigh?
a. pectineus
b. rectus femoris
c. iliopsoas
d. sartorius
e. adductor magnum
E.
This nerve innervates a muscle that inserts onto the greater trochanter.
a. obturator nerve
b. femoral nerve
c. both
d. neither
D.
Which has an origin from the ischial tuberosity
a. gluteus maximus
b. iliopsoas
c. biceps femoris
d. rectus femoris
e. gluteus medius
B
Which has an origin from the ischial tuberosity
a. gluteus maximus
b. iliopsoas
c. biceps femoris
d. rectus femoris
e. gluteus medius
C
A misplaced intramuscular injection into the gluteal region infiltrated the sciatic nerve and its surroundings, giving rise to temporary paralysis of the muscles supplied by that nerve. All of the following would be involved EXCEPT for the:
a. tibialis anterior
b. soleus
c. peroneus brevis
d. gracilis
e. popliteus
D
This muscle does not dorsiflex (extend) the foot:
a. Tibialis anterior
b. Extensor hallucis longus
c. Extensor digitorum longus
d. Extensor digitorum brevis
e. Peroneus tertius
D.
A simpler way of recalling this is to understand that for a muscle to dorsiflex the foot, it has to pass superior and anterior to the ankle joint. This may be applied to any other joints: flexors of the elbow joint need to pass anteriorly, extensors of the knee joint need to pass anteriorly etc. With this concept in mind, it is then easy to see that since the extensor digitorum brevis muscle is a short intrinsic muscle of the foot and it does not pass superiorly and anteriorly over the ankle joint, it does not carry out dorsiflexion of the foot.
The superficial fibular (peroneal) nerve innervates muscles that
a. Extend thigh and leg
b. Flex thigh and leg
c. Flex leg and foot
d. Dorsiflex and invert foot
e. Plantarflex and evert foot
E
The superficial fibular (peroneal) nerve originates from the common fibular nerve after its bifurcation near the neck of the fibula, carrying nerve fibers from the ventral rami of L5, S1 and S2 spinal segments. The superficial fibular nerve has both sensory and motor innervation:
* Motor innervation – fibularis longus and brevis, which both evert and weakly plantarflex the foot
* Sensory innervation – the skin over the anterior surface of the distal third of the leg and the dorsal aspect of the medial 3 ½ digits, excluding the nail beds of the corresponding digits, and a small area between the big toe and second toe supplied by the deep fibular nerve (also known as the first interdigital cleft).
In the popliteal fossa,
a. The sciatic nerve gives off the superficial fibular (peroneal) nerve
b. The long saphenous vein drains into the popliteal vein
c. Popliteal vein continues as the external iliac vein
d. Tendon of semimembranosus strengthens the capsule of the knee
e. The popliteus muscle is innervated by the common fibular (peroneal) nerve
D
