Overview of the Lower Extremity Flashcards
What are the Divisions of the Lower Extremity?
- Gluteal region
- Thigh (hip to knee)
- Popliteal fossa (posterior aspect of knee)
- Leg (knee to ankle)
- Foot (dorsal and plantar aspects)
Describe the Bones of the lower extremity
- Hip bones (ilium + ischium + pubis),
- femur,
- patella,
- tibia (medial bone of leg),
- fibula (lateral bone of leg),
- 7 tarsals
- 5 metatarsals (proximal part is the base, distal part is the head),
- 14 phalanges (proximal, middle, distal; the hallux (big toe) has a proximal and distal phalanx only)
What are the 7 tarsals?
- calcaneus
- talus
- navicular
- cuboid
- medial
- intermediate
- lateral cuneiforms
What are the parts of the femur
- Head
- Neck
- Shaft (body) with linea aspera (on posterior surface)
- Medial and lateral femoral condyles (distal)
What are the parts of the tibia
- Medial and lateral tibial condyles (proximal)
- Shaft (body)
- Medial malleolus is the distal protuberance on the medial side of the ankle
What are the parts of the fibula
- Head
- Shaft (body)
- Lateral malleolus is the distal protuberance on the lateral side of the ankle
What are the Joints and Movements of the Lower Extremity?
- Hip Joint –> Ball and socket synovial joint
- Knee Joint –> Hinge synovial joint
- Ankle (Talocrural) Joint –> Hinge synovial joint
- Subtalar Joint –> Synovial joint
- Metatarsophalangeal (MTP) Joints –> Synovial joints
- Interphalangeal (IP) Joints –> Hinge synovial joints
Describe the Hip Joint connection and movement
- Acetabulum of the hip bone articulates with the femoral head
- Flexion reduces the angle between the thigh and trunk anteriorly
- Extension increases the angle between the thigh and trunk anteriorly
- Abduction draws the thigh away from the midline of the body
- Adduction draws the thigh towards the midline of the body
- Medial rotation femur rotates medially along its long axis
- Lateral rotation femur rotates laterally along it long axis
Describe the knee joint connection and movement
- Femoral condyles articulate with the tibial condyles
- Flexion brings the leg closer to the posterior aspect of the thigh
- Extension draws the leg away from the posterior aspect of the thigh
Describe the ankle (Talocrural) Joint connection and movement
- Talus articulates with distal tibia and lateral malleolus of the fibula
- Dorsiflexion brings the foot closer to the anterior aspect of the leg (directs toes superiorly)
- Plantarflexion draws the foot away from the anterior aspect of the leg (directs toes inferiorly)
Describe the Subtalar Joint connection and movement
- Synovial joint between the talus and the calcaneus
- Eversion causes the sole of the foot to face laterally
- Inversion causes the sole of the foot to face medially
Describe how the muscle/tendon units move the foot
Muscles will have multiple actions (e.g., dorsiflexion & inversion), depending on where their tendon passes relative to the talocrural and subtalar axes of motion.
SEE PICTURE
- Synovial joints between the metatarsals and the proximal phalanges
- Flexion of toes (towards the ground)
- Extension of toes (away from the ground)
- Abduction (movement away from the second digit axis)
- Adduction (movement towards the second digit axis)
- Synovial joints between the metatarsals and the proximal phalanges
- Flexion of toes (towards the ground)
- Extension of toes (away from the ground)
- Abduction (movement away from the second digit axis)
- Adduction (movement towards the second digit axis)
Describe the Interphalangeal (IP) Joints connection and movement
- Hinge synovial joints between the phalanges
- Proximal interphalangeal joints (PIPs) are located between the proximal and middle phalanges
- Distal interphalangeal joints (DIPs) are located between the middle and distal phalanges
- The hallux has a single IP joint between its proximal and distal phalanges
- Flexion of toes (towards the ground
- Extension of toes (away from the ground)
What is the Fascia of the Lower Extremity?
- Superficial fascia
- Deep fascia
Describe the Superficial fascia
Contains: fat, cutaneous nerves, superficial veins, lymphatic vessels and lymph nodes
Describe the Deep fascia
- Dense connective tissue
- Invests the lower extremity muscles like an elastic stocking; prevents muscles from bulging during contraction; efficient mechanism to pump blood back to the heart
What is the Deep fascia of the thigh called?
Fascia lata
What is the Deep fascia of the leg called?
Crural fascia
Describe the attachment of the Fascia lata
-Firmly attached to pubis, inguinal ligament, iliac crest, sacrum, coccyx, and ischial tuberosity
Oval shaped window in the fascia lata is the _______
-Saphenous opening: it is located just inferior to the inguinal ligament –> the great saphenous vein and associated lymphatic vessels pass through this opening
Lateral thickening of fascia lata is the ___________
Iliotibial tract (or band)
What septa arise from the fascia lata?
- 3 intermuscular septa arise from the fascia lata and attach to the linea aspera of the femur
- These septa divide the thigh into 3 compartments: anterior, posterior, and medial
What septa arise from the Crural fascia?
- Continuous with fascia lata
- 2 intermuscular septa arise from the crural fascia and attach to the fibula
- These septa (along with the interosseous membrane between the tibia and fibula) divide the leg into 3 compartments: anterior, posterior, and lateral
- Another septum separates the posterior compartment into superficial and deep layers
- Near the ankle joint, the deep fascia forms extensor, flexor, and fibular retinacula; these bands keep tendons in place around the ankle joint
What are the Veins of the Lower Extremity?
- Superficial and deep veins in the lower extremity
- Perforating veins
-These veins all have valves, but the valves are more numerous in the deep veins
What are the superficial veins?
- Great saphenous vein
- Small saphenous vein
Describe the location of the Great saphenous vein?
- Arises from dorsal aspect of the foot
- Passes anterior to the medial malleolus
- Ascends along the medial aspect of the leg and thigh
- Enters the saphenous opening in the fascia lata
- Drains into the femoral vein
- Receives numerous tributaries as it ascends, and anastomoses with the small saphenous vein
Describe the saphenous cut down procedure
- The great saphenous vein can be accessed anterior to the medial malleolus to administer medications, fluids, etc.
- The procedure is effective even in infants, obese and dehydrated patients (with collapsed veins).
What is the Great saphenous vein used for surgically? Why is THAT vein used?
-Can be used in coronary bypass surgery
- (a) the vein is superficial and easily accessible;
- (b) the wall of the great saphenous vein contains a high percentage of muscular and elastic fibers; and
- (c) the vein is long, with long distances between tributaries (easy to harvest usable lengths)
Describe the Small saphenous vein
- Arises from lateral side of foot
- Passes posterior to the lateral malleolus of the ankle
- Enters popliteal fossa and drains into popliteal vein
Describe the Perforating veins
- Connect the superficial and deep veins
- Contain valves that allow blood to flow only from sf deep veins
Describe the Musculovenous pump
- When muscles contract, blood in the deep veins is propelled to the femoral and then external iliac veins (musculovenous pump)
- Valves in deep veins prevent reflux of blood inferiorly
- Valves in the perforating veins prevent reflux of blood from the deep to superficial veins
When do Varicose veins occur?
- When valves in the perforating veins become incompetent, allowing large amounts of blood to reflux from the deep to the superficial veins.
- The superficial veins become distended as they receive this large volume of blood.
Describe Lymphatics of the Lower Extremity (Gluteal Region)
- Lymph from superficial tissues of the gluteal region –> superficial inguinal lymph nodes –> external iliac lymph nodes
- Lymph from deep tissues of the gluteal region –> superior and inferior gluteal lymph nodes –> internal iliac lymph nodes
Describe SUPERFICIAL Lymphatics of the Lower Extremity (Thigh, Leg, and Foot)
- Superficial lymphatic vessels accompanying the great saphenous vein drain into the superficial inguinal lymph nodes
- Superficial lymphatic vessels accompanying the small saphenous vein drain into the popliteal lymph nodes –> deep inguinal lymph nodes
- Both superficial and deep inguinal lymph nodes drain into the external iliac nodes
Describe DEEP Lymphatics of the Lower Extremity (Thigh, Leg, and Foot)
- Deep lymphatic vessels accompany the deep veins (e.g., popliteal, femoral) and drain into deep inguinal lymph nodes located medial to the femoral vein
- Both superficial and deep inguinal lymph nodes drain into the external iliac nodes
What are the Dermatomes of the Lower Extremity?
-You are responsible for knowing the dermatome map shown in C and D; however, there is a great deal of overlap between adjacent spinal nerve territories. In addition, please note that other maps (e.g., E, F) may be used by some clinicians.
SEE PICTURE
