Lower Limb: MRCEM Primary questions with answers

Lower Limb follows the leg from hip to foot. Within MRCEM Primary, anatomy carries 60 of the 180 questions. The lessons cover bones, joints, muscles, arterial supply, venous and lymphatic drainage, nerves, dermatomes, myotomes and reflexes, and other significant structures. In emergency care this helps you assess fractures, dislocations, limb ischaemia and nerve injuries after trauma.

5 free questions below, each with the answer and the full explanation · 269 in the full bank · Last updated after the 27 October 2026 MRCEM Primary sitting.

1. Question 1 · Venous Drainage of Lower Limb

   You are teaching a group of medical students the venous drainage of the lower limb. Regarding the course of the great saphenous vein, which one of the following is correct?

   1. ABegins as the upward continuation of the lateral marginal vein of the foot
   2. BJoin the femoral vein above the inguinal ligament
   3. CRuns behind the medial malleolus
   4. DTravels with saphenous nerve along its course
   5. EEnters the femoral vein on its anteromedial side
   Show answer and explanation

   Answer: E. The great saphenous vein joins the femoral vein on its anteromedial side below the inguinal ligament.

   • A: It begins from the medial, not lateral, marginal vein.
   • B: It joins below, not above, the inguinal ligament.
   • C: It passes anterior to, not behind, the medial malleolus.
   • D: The saphenous nerve accompanies it only below the knee.

   Full explanation: Venous Drainage of Lower Limb

   Superficial Veins of the Lower Limb

   • The great saphenous vein: originate from medial side of the dorsal venous arch in the foot, passes anterior to the medial malleolus (not posterior), travels up the medial side of leg, knee and thigh to pass into saphenous opening in deep fascia covering the femoral triangle and join with the femoral vein below the inguinal ligament. 
   • The small saphenous vein: originate from lateral side of dorsal venous arch in the foot, passes posterior to lateral malleolus and up the back of leg to pierce the deep fascia and join the popliteal vein in popliteal fossa posterior to knee. 

   Clinical Pearls:

   Varicose veins: Develop in superficial veins of the lower limb because of reduced elasticity and incompetent valves in the veins causing them to become dilated and tortuous. 

    

2. Question 2 · Lower Limb Other Significant Structures

   You are examining a patient with femoral hernia; your consultant asks which structure forms the medial border of the femoral canal?

   1. AFemoral vein
   2. BPectineal ligament
   3. CFemoral nerve
   4. DLacunar ligament
   5. EInguinal ligament
   Show answer and explanation

   Answer: D. The lacunar ligament forms the medial border of the femoral canal.

   • A: The femoral vein forms the lateral border.
   • B: The pectineal ligament forms the posterior border.
   • C: The femoral nerve lies outside the femoral sheath.
   • E: The inguinal ligament forms the anterior border.

   Full explanation: Lower Limb Other Significant Structures

   Femoral Triangle:

   The wedge-shaped area is located within the superomedial aspect of the anterior thigh. 

   Superior border	Inguinal ligament
   Floor	Pectineus, iliopsoas and adductor longus muscles
   Roof	Fascia-Lata
   Medial border	Medial border of adductor longus muscle
   Lateral border	Medial border of sartorius muscle
   Contents	Femoral nerve, femoral artery, femoral vein, femoral canal

   High Yield:  

   Contents of Femoral Triangle:

   From lateral to medial: Useful mnemonic (NAVEL)  

   • Femoral nerve  
   • Femoral artery  
   • Femoral vein  
   • Empty space (consists of femoral canal)  
   • Lymph nodes  

   Note: Femoral nerve lies lateral to femoral artery and vein 

   Clinical pearls: In Femoral hernia part of the bowel pushes into the femoral canal underneath the femoral triangle. 

   Femoral Sheath:

   The femoral sheath originates as a prolongation of extraperitoneal fascia and encloses the femoral artery, femoral vein and femoral canal. 

   Note: The femoral nerve does not lie within the femoral sheath, but instead lies lateral to it. 

     

   Femoral Canal:

   The Femoral canal lies most medial of the femoral sheath.  

   Borders of the femoral canal: (Useful mnemonic LAMP: FILP)  

   • Lateral border: Femoral vein (Immediately lateral)  
   • Anterior border: Inguinal ligament  
   • Medial border: Lacunar ligament  
   • Posterior ligament: Pectineal ligament, Pectineus muscle and superior ramus of pubic bone.  

   Contents: Deep inguinal lymph nodes, lymphatic vessels, empty space and loose connective tissue. 

   Clinical pearls: In Femoral hernia part of the bowel pushes into the femoral canal underneath the femoral triangle. 

    

   The Arches of Foot:

   Foot has three arches, one transverse arch and two longitudinal (medial and lateral) arches. Shape of arches allows them to act in the same way as a spring, bearing the weight of the body and absorbing the shock produced during locomotion. 

   • Formed by tarsal, metatarsal bones and supported by ligaments. 

   Medial longitudinal arch	Calcaneus, talus, navicular, three cuneiforms and medial three metatarsal bones	Spring ligament, deltoid ligament, plantar aponeurosis and tendons of the tibialis anterior and tibialis posterior muscles
   Lateral longitudinal arch	Calcaneus, cuboid and lateral two metatarsal bones	Plantar aponeurosis, fibularis longus tendon, long and short plantar ligament
   Transverse arch	metatarsal bases, the cuboid and the three cuneiform bones	Fibularis longus and tibialis posterior, long and short plantar ligament

   Popliteal Fossa:

   Diamond shaped area located on the posterior aspect of the knee, and is the pathway to pass by which vessels and nerves pass between the thigh and the leg. 

     

   Boundaries and Contents of Popliteal Fossa:

   Superomedial border	Semimembranosus
   Superolateral border	Biceps femoris
   Inferomedial border	Medial head of gastrocnemius (Recall)
   Inferolateral border	Lateral head of gastrocnemius and plantaris
   Floor	The floor of the popliteal fossa is formed by the posterior surface of the knee joint capsule, popliteus muscle and posterior femur.
   Roof	The roof is made of up two layers: popliteal fascia and skin. The popliteal fascia is continuous with the deep fascia of the leg.
   Contents	Popliteal artery, popliteal vein, tibial nerve, common fibular nerve

   Contents (From medial to lateral): Popliteal artery, popliteal vein, tibial nerve and common fibular nerve. 

   Note: Tibial and common fibular nerve are the most superficial contents of the popliteal fossa. Both are the branches of sciatic nerve 

   • The common fibular nerve follows the biceps femoris tendon, travelling along the lateral margin of the popliteal  
   • Tibial nerve lies more medial to common fibular nerve. 

    

    

    

3. Question 3 · Nerves of the Lower Limb

   A man aged 24 self presents to ED following a fight in a nearby street. He has sustained multiple stab wounds and laceration of the medial compartment of the thigh. Which one of the following nerves is most likely injured in the adductor canal?

   1. AObturator nerve
   2. BSaphenous nerve
   3. CFemoral nerve
   4. DTibial nerve
   5. ESciatic nerve
   Show answer and explanation

   Answer: B. The adductor canal transmits the saphenous nerve, which is vulnerable to injury there.

   • A: Obturator nerve supplies the medial thigh and does not pass through the canal.
   • C: Femoral nerve divides in the femoral triangle before the canal.
   • D: Tibial nerve runs in the popliteal fossa and posterior leg.
   • E: Sciatic nerve runs in the posterior thigh.

   Full explanation: Nerves of the Lower Limb

   Femoral nerve 

   • Nerve roots: L2-L4 
   • Motor functions: Innervates the anterior thigh muscles. 
   • Sensory functions: 

   Anterior cutaneous branches	Skin over anteromedial thigh
   Saphenous nerve	Medial side of the leg and foot.

   Anatomical course: 

   • The femoral nerve is the largest branch of the lumbar plexus. It is derived from the anterior rami of nerve roots L2, L3 and L4 
   • After arising from the lumbar plexus, the femoral nerve travels inferiorly through the psoas major muscle of the posterior abdominal wall. It supplies branches to the iliacus and pectineus muscles in the abdomen prior to entering the thigh. 
   • Passing underneath the inguinal ligament to enter the femoral triangle, in this triangle femoral nerve is located lateral to femoral vessels (Femoral artery and Vein). Useful Mnemonic from lateral to medial (NAVEL). Below the inguinal ligament femoral nerve divides into anterior and posterior divisions 

    

   1: Anterior division of the femoral nerve 

   • Anterior cutaneous branches 
   • Branch to sartorius 
   • Branch to pectineus 

   2: Posterior division of the femoral nerve 

   • Saphenous nerve 
   • Branches to quadriceps femoris 

   Note: In posterior abdominal wall. Femoral nerve supplies branches to the iliacus and pectineus muscles prior to entering the thigh. 

    

   Femoral nerve Sensory innervation of lateral and posterior thigh: (Important to remember)

   Clinical pearls: Damage to the femoral nerve causing impaired flexion at hip and impaired extension of the leg resulting from paralysis of the quadriceps femoris (Which include Rectus femoris, Vastus lateralis, Vastus medialis and Vastus intermedius. 

   Sensory loss: Loss of sensation over anteromedial thigh, anteromedial knee, medial leg and medial foot. 

    

   Obturator nerve 

   • Nerve roots: L2-L4 
   • Motor functions: Innervates the medial thigh muscles. 
   • Sensory functions: Upper medial thigh via cutaneous branches 

    

   Anatomical course: Arises from the lumbar plexus and enters the thigh through obturator foramen. 

   Note: The obturator nerve innervates all of the muscles of the medial compartment of the thigh (except for the hamstring part of the adductor magnus innervated by the tibial portion of the sciatic nerve). 

   Clinical: Damage to the obturator nerve causes weakness of adduction, resulting in a lateral swinging of the limb during walking 

    Sensory Loss: Loss of sensation over upper medial thigh   

    

   Sciatic nerve 

   • Is the largest nerve in the body. Derived from the lumbosacral plexus and receives fibers from L4-S3. 

   Function: 

   1: Motor functions: Innervates the muscles of the posterior thigh (biceps femoris, semimembranosus and semitendinosus) and the hamstring portion of the adductor magnus (remaining portion of which is supplied by the obturator nerve). 

   • Indirectly innervates (via its terminal branches) all the muscles of the leg and foot. 

   2: Sensory functions: No direct sensory functions. Indirectly innervates (via its terminal branches) the skin of the lateral leg, heel, and both the dorsal and plantar surfaces of the foot. 

    

   Anatomical course: Sciatic nerve leaves the pelvis and enters the gluteal region via greater sciatic foramen. It emerges inferiorly to the piriformis muscle and descends in an inferolateral direction and entering the posterior compartment of the thigh. In the posterior compartment of the thigh, the sciatic nerve lies on the adductor magnus muscle and is crossed by the long head of the biceps femoris muscle. Within the posterior thigh, the sciatic nerve gives rise to branches to the hamstring muscles and adductor magus. When the sciatic nerve reaches the apex of the popliteal fossa, it terminates by bifurcating into the tibial and common fibular nerves. 

   Clinical pearls: 

   Intramuscular injections in the gluteal region: The anatomical course of the sciatic nerve must be considered when administering intramuscular injections into the gluteal region. The region can be divided into quadrants using 2 lines. 

   • One line descends vertically from the highest point on the iliac crest. 
   • Other line passes through vertical line halfway between the highest point. 

   Note: Sciatic nerve lies in the lower medial quadrant. To avoid injury of sciatic nerve IM injections in the gluteal region only be given in upper lateral quadrant. 

    

   Tibial nerve 

    Branch of sciatic nerve. Arises at apex of popliteal fossa receiving nerve fibers from L4-S3. 

   Functions: 

   Motor: Innervates all the muscles in posterior compartment of the leg and the majority of the intrinsic foot muscles. 

   Sensory: In the popliteal fossa, the tibial nerve gives off cutaneous branches. These combine with branches from the common fibular nerve to form the sural nerve. This sensory nerve innervates the skin of the posterolateral side of the leg and the lateral side of the foot and heel. 

    

   Sensory branches of tibial nerve: 

    

   Clinical pearls: Damage to the tibial nerve causes loss of plantar flexion of the foot and impaired inversion. This presents with difficulty in getting the heel off the ground and a shuffling gait, resulting in characteristic clawing of the toes and sensory loss on the sole of the foot, affecting posture and locomotion. 

    

    

   Common fibular (Peroneal nerve) 

   Arises as the smaller terminal portion of the sciatic nerve at the apex of the popliteal fossa. The common fibular nerve continues by wrapping around the neck of the fibula and passing between the attachments of the fibularis longus muscle to enter the lateral compartment of the leg where it divides into its terminal branches, the superficial and deep fibular nerves. 

    

    

   Note: It is very important to remember direct innervation of common fibular nerve.  

   Deep fibular nerve root: L4-L5 

   Superficial fibular nerve root: L4-S1. 

   Clinical pearls: 

   1: Common fibular nerve injury: Damage to the common fibular (peroneal) nerve may occur as a result of fracture of the head or neck of the fibula because it passes behind the head of the fibula and then winds laterally around the neck. The nerve damage results in foot drop (loss of dorsiflexion) and loss of sensation on the dorsum of the foot and lateral aspect of the leg and causes paralysis of all muscles in the anterior and lateral compartments of the leg (dorsiflexors and evertors muscles of the foot). 

   2: Superficial fibular nerve: May be damaged by fracture of the fibula. As the muscles that the superficial fibular nerve innervates are evertors, injury to the nerve may result in a loss of eversion and loss of sensation over the lower anterolateral leg and dorsum of foot 

   3: Deep fibular nerve:  

   Motor Loss: Loss of dorsiflexion of ankle resulting in foot drop. In foot drop foot will appear permanently plantarflexed, foot drop with high-stepping gait, weakness of foot inversion. 

   Sensory Loss: Loss of sensation over webspace between 1st and 2nd toes. 

   Note: Footdrop is due to Common fibular or common peroneal nerve or also due to deep fibular nerve injury. 

4. Question 4 · Muscles of the Lower Limb

   A man aged 42 attends ED after a hip injury. On examination you find weak lateral rotation. Which of the following muscles is most likely to have been injured:

   1. AGracilis
   2. BPectineus
   3. CPiriformis
   4. DAdductor longus
   5. ESemitendinosus
   Show answer and explanation

   Answer: C. Piriformis is one of the six lateral rotators of the hip.

   • A: Gracilis adducts the thigh and flexes the knee.
   • B: Pectineus flexes and adducts the thigh.
   • D: Adductor longus adducts the thigh.
   • E: Semitendinosus extends the hip and flexes the knee.

   Full explanation: Muscles of the Lower Limb

   Muscles of Gluteal Region:

   Muscles of the gluteal region are divided into two groups. 

   1: Superficial gluteal muscles 

   Muscle	Function	Innervation
   Gluteus maximus	Main extensor of thigh, lateral rotation and abduction at hip	Inferior gluteal nerve
   Gluteus Medius	Abduction and medial rotation at hip Stabilizes the pelvis and prevent dropping on the contralateral side.	Superior gluteal nerve
   Gluteus minimus	Abduction and medial rotation at hip Stabilizes the pelvis and prevents dropping on the contralateral side.	Superior gluteal nerve

   Note: Greater trochanter of femur is site of insertion of gluteus Medius, minimums and piriformis. 

    

   2: Deep gluteal muscles: 

   Muscle	Function	Innervation
   Piriformis	Lateral rotation and abduction at hip	Branches from S1 And S2
   Obturator Internus	Lateral rotation and abduction	Nerve to obturator internus
   The Gemelli (Superior and Inferior)	Lateral rotation and abduction	Superior Gemelli: Nerve to obturator internus Inferior Gemelli: Nerve to quadratus femoris
   Quadratus Femoris	Lateral rotation	Nerve to quadratus femoris

   Note: The piriformis muscle is an important landmark in the gluteal region. The superior gluteal nerve and vessels emerge into the gluteal region superiorly to the piriformis. Sciatic nerve enters the gluteal region directly inferior to the piriformis muscle.  

   Clinical pearls: 

   Trendelenburg Sign: Trendelenburg gait or waddling gait occurs when your hip abductor muscles are weakened. This muscle group includes the gluteus Medius and minimus innervated by superior gluteal nerve. The weakness of these muscles causes drooping of the pelvis to the contralateral side while walking. 

   The Trendelenburg sign is produced when the patient is asked to stand without support on each leg. In a positive sign, pelvic drop will occur on the unsupported leg. For example, if the right gluteal muscles are weak, the left side of the pelvis will drop. 

    

   Anterior compartment of thigh muscles:

   Muscle	Function	Innervation
   Sartorius	Flexion, abduction and lateral rotation at hip Flexion at knee	Femoral nerve
   Iliacus	Flexion and lateral rotation at hip	Femoral nerve
   Psoas major	Flexion and lateral rotation at hip	Anterior rami L1 – L3
   Pectineus	Flexion and adduction at hip	Femoral nerve
   Quadriceps femoris (4 Muscles)	Rectus femoris: Extension of knee and flexion at hip joint Vastus lateralis: Extension at knee Vastus intermedius: Extension at knee Vastus medialis: Extension at knee	Femoral nerve

   
   Note: All the muscles of anterior compartment of thigh are flexors of thigh at hip joint, while quadriceps femoris is extensor of thigh at knee joint and Sartorius also flexes thigh at knee. 

   Note:    Sartorius originates from anterior superior iliac spine 

   • Rectus femoris originates from anterior inferior iliac spine. 

    

   Medial Compartment of thigh muscles:

   Medial compartment consists of five Indvidual muscles. 

   All the muscles of medial compartment of thigh causes adduction of thigh at hip joint except obturator externus which causes lateral rotation of thigh at hip joint.  

   Gracilis along with adduction at hip joint also assist in flexion at knee joint. 

    

   Muscle	Function	Innervation
   Adductor longus	Adduction and medial rotation at hip	Obturator nerve
   Adductor brevis	Adduction at hip	Obturator nerve
   Adductor magnus	Adduction and medial rotation at hip Hamstring part: Adduction and extension of the thigh	Adductor part: Obturator nerve Hamstring part: tibial part of sciatic nerve
   Obturator externus	Lateral rotation at hip joint	Obturator nerve
   Gracilis	Adduction at hip Flexion at knee	Obturator nerve

    

   Posterior thigh muscles: Also known as hamstrings, consists of three individual muscles. 

   Muscle	Function	Innervation
   Biceps femoris (2 heads) Long head and short head	Flexion at knee Extension and lateral rotation of thigh at hip joint	Long head: Tibial part of the sciatic nerve. Short head: Common fibular branch of sciatic nerve
   Semitendinosus	Flexion at knee Extension and medial rotation of thigh at hip joint	Tibial part of the sciatic nerve.
   Semimembranosus	Flexion at knee Extension and medial rotation of thigh at hip joint	Tibial part of the sciatic nerve.

   Note: All the muscles of posterior compartment of thigh are extensors of thigh at hip and flexors at knee joint. While Biceps femoris is also lateral rotator of thigh at hip joint and Semitendinosus and Semimembranosus also medial rotators of thigh at hip joint 

    Clinical pearls: All the muscles of the posterior thigh originate from the ischial tuberosity of the pelvis. In some cases, mostly in young athletes, sudden and forceful contraction of the hamstring muscles can result in an avulsion fracture of the ischial tuberosity. It can also be associated with sciatic nerve damage. 

    

   Muscles in the anterior compartment of leg:

   Anterior leg consists of four muscles 

   Clinical pearls: Foot Drop (Discussed in nerves of the lower limb) 

    

   Muscles in the Posterior compartment of leg: Consists of seven muscles divided into superficial and deep groups. All are innervated by tibial nerve 

   Superficial group: Mnemonic (GPS)

   Muscle	Function	Innervation
   Gastrocnemius	Plantarflexion of foot Flexion of leg knee because it crosses knee	Tibial nerve
   Plantaris	Plantarflexion of foot Flexion of leg knee because it crosses knee	Tibial nerve
   Soleus	Plantarflexion of foot	Tibial nerve

   Deep muscles in the posterior leg:

   Muscle	Function	Innervation
   Popliteus	Initiating lateral rotation of femur on tibia and unlocks the knee joint from extended and locked position so that flexion can occur.	Tibial nerve
   Flexor digitorum longus	Flexion of lateral four toes	Tibial nerve
   Flexor hallucis longus	Flexion of great toe	Tibial nerve
   Tibialis posterior	Plantarflexion and inversion of foot Maintains medial arch of foot	Tibial nerve

   Clinical pearls: 

   Ruptured calcaneal tendon: Tear of calcaneal tendon occurs during forceful plantarflexion of the foot. Patients will be unable to plantarflex the foot and affected foot will be permanently dorsiflexed. 

    

    

   Muscles in the lateral compartment of leg:

   Consists of two muscles, fibularis longus and brevis also called peroneus longus and peroneus brevis. 

   Muscle	Attachment	Function	Innervation
   Fibularis longus	Origin: superior and lateral surface of the fibula Insertion: 1st metatarsal and medial cuneiform	Eversion and plantarflexion of foot Support lateral arch as well as transverse arch of foot	Superficial fibular nerve
   Fibularis brevis	Origin: Inferolateral surface of fibular shaft Insertion:5th metatarsal	Eversion of foot	Superficial fibular nerve

    

   Muscles of the Sole of foot: 

   Muscles of sole of foot. (4 layers) = Must remember highlighted one 

   • First layer: Abductor hallucis, flexor digitorum brevis & abductor digitorum minimi 
   • Second layer: flexor digitorum accessorius, 4 lumbricals and tendons of flexor hallucis longus and flexor digitorum longus 
   • Third layer: flexor hallucis brevis, flexor digitorum minimi brevis & adductor hallucis 
   • Fourth layer: Plantar and dorsal interossei muscles, Two long tendons of extrinsic muscles – tibialis posterior and fibularis longus. 

   Note: Plantar arteries and nerves lie within the first and second layer of the sole of foot. 

    

5. Question 5 · Arterial Supply of Lower Limb

   You have been asked to collect an arterial blood gas from a patient's femoral artery. Which structure forms the medial border of the femoral triangle:

   1. AAdductor brevis muscle
   2. BGracilis muscle
   3. CAdductor magnus muscle
   4. DAdductor longus muscle
   5. EPectineus muscle
   Show answer and explanation

   Answer: D. The medial border of adductor longus forms the medial border of the femoral triangle.

   • A: Adductor brevis forms part of the floor.
   • B: Gracilis is not a border of the triangle.
   • C: Adductor magnus is not a border.
   • E: Pectineus forms part of the floor.

   Full explanation: Arterial Supply of Lower Limb

   1: Femoral Artery:

   The femoral artery is a continuation of the external iliac artery. It begins behind the inguinal ligament, where it lies midway between the anterior superior iliac spine and the symphysis pubis (the site for taking a femoral pulse). The artery descends through the femoral triangle and the adductor canal, and it leaves the front of the thigh by passing through the opening in the adductor magnus and then entering the popliteal space as the popliteal artery. 

     Note: In the femoral triangle, the artery is related laterally to the femoral nerve and medially, in the upper part of its course, to the femoral vein 

    

   Branches of femoral artery:

   • Superficial circumflex iliac artery, which arises just below the inguinal ligament and runs laterally toward the anterior superior iliac spine. 
   • Superficial epigastric artery, which arises just below the inguinal ligament and runs upward to the abdominal wall. 
   • Deep external pudendal artery and the superficial external pudendal artery arise just below the inguinal ligament and run medially to supply the skin of the scrotum (or labium majus). 
   • Profunda femoris artery, which is a large branch that arises from the femoral artery approximately 4 cm below the inguinal ligament. It supplies structures in the anterior, medial, and posterior fascial compartments of the thigh. 

    

   2: Popliteal artery:

   Popliteal artery is a continuation of femoral artery. It extends from the opening in the adductor magnus to the lower border of popliteus muscle, where it divides into anterior and posterior tibial arteries. 

   • Anterior Tibial Artery: 

      The anterior tibial artery arises at the bifurcation of the popliteal artery in the popliteal fossa. It passes forward between the tibia and the fibula through the upper part of the interosseus membrane and enters the anterior compartment of the leg. It then descends with the deep peroneal nerve to the front of the ankle joint, where it becomes the dorsalis pedis artery 

   • Posterior Tibial Artery

   The posterior tibial artery arises at the bifurcation of the popliteal artery in the popliteal fossa. It descends in the posterior compartment of the leg and is accompanied by the tibial nerve. The artery terminates behind the medial malleolus by dividing into the medial and the lateral plantar arteries. 

   •  Medial Plantar Artery

   The medial plantar artery is the smaller of the terminal branches of the posterior tibial artery. It runs forward along the medial border of the foot with the medial plantar nerve, and it gives off many muscular and cutaneous branches. 

   • Lateral Plantar Artery

     The lateral plantar artery is the larger of the terminal branches of the posterior tibial artery. It runs for- ward deep to the abductor hallucis and the flexor digitorum brevis muscles with the lateral plantar nerve, and it ends by curving medially to form the plantar arch through anastomosis with the dorsalis pedis artery. The plantar arch gives off perforating and metatarsal arteries; the metatarsal arteries give rise to digital arteries. 

    

   Clinical high yield:

   Medical personal should know the precise position of the main arteries within the lower limb. 

   • Femoral artery: This enters the thigh behind the inguinal ligament at a point midway between the anterior superior iliac spine and the symphysis pubis. 
   • Popliteal artery: This artery can be felt by gentle palpation in the depths of the popliteal space, provided that the deep fascia is fully relaxed by passively flexing the knee joint.  
   • Dorsalis pedis artery: This artery lies between the tendons of the extensor hallucis longus and the extensor digitorum longus, midway between the medial and lateral malleoli on the front of the ankle. 

   • Posterior tibial artery: This artery passes behind the medial malleolus, beneath the flexor retinaculum, and lies between the tendons of flexor digitorum longus and the flexor hallucis longus. The pulsations of the artery can be felt midway between the medial malleolus and the heel.