Week 11 - Posterior Leg Flashcards
Where are the pulse points in the lower limb?
- Femoral pulse: mid-inguinal point
- Popliteal pulse: deep in popliteal fossa, if leg is flexed then the fascia will relax so it will be easier to find
- Dorsalis pedis: on the dorsum of the foot, just lateral to extensor hallucis longus tendon
What are the superficial muscles in the posterior leg?
- Gastrocnemius
- Plantaris
- Soleus
What are the collective actions of the posterior leg muscles?
- Plantarflex foot
- Invert foot
What is the innervation of the superficial muscles in the posterior leg?
Tibial nerve
What is the insertion of the superficial muscles in the posterior leg?
They all insert into the calcaneus of the foot, via the calcaneal tendon
What are the actions of gastrocnemius?
- Plantarflexes at the ankle
- Flexes at the knee
What is the structure of the gastrocnemius?
- Has 2 heads: medial and lateral
- Converge to form a single muscle body
What is plantaris?
A small muscle with a long tendon
- Found in the superficial posterior leg
- Absent in 10% of people
What are the actions of plantaris?
- Plantarflexes at ankle joint
- Flexes knee
What are the actions of soleus?
Plantarflexes the foot
What is the innervation of the deep muscles in the posterior leg?
Tibial nerve
What are the deep muscles in the posterior leg?
- Popliteus
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
What is the action of popliteus?
Laterally rotates the femur on the tibia, unlocking the joint so that flexion at the knee joint can occur
What is the action of tibialis posterior?
- Inverts the foot
- Plantarflexes the foot
- Maintains the medial arch of the foot
What is the action of flexor digitorum longus?
Flexes the lateral 4 toes
What is the action of flexor hallucis longus?
Flexes the great toe
What are the superficial veins of the lower limb?
- Great saphenous vein
- Small saphenous vein
What is the path of the great saphenous vein?
- Formed by the dorsal venous arch of the foot and the dorsal vein of the great toe
- Ascends up the medial side of the leg
- Passes anteriorly to the medial malleolus
- Passes posteriorly to the medial condyle at the knee
- Terminates by draining into the femoral vein immediately inferior to the inguinal ligament
What is the path of the small saphenous vein?
- Formed by the dorsal venous arch of the foot and the dorsal vein of the little toe
- Moves up the lateral, posterior side of the leg
- Passes posteriorly to the lateral malleolus
- Moves between the 2 heads of the gastrocnemius
- Empties into the popliteal vein in the popliteal fossa
Describe the deep veins of the lower limb
The deep veins accompany and share the name of the major arteries in the lower limb
- Some veins from the dorsal venous arch penetrate deep into the leg, forming the anterior tibial vein
- On the plantar aspect of the foot, the medial and lateral plantar veins arise
- – These combine to form the posterior tibial and fibular veins
- The anterior tibial, posterior tibial and fibular veins unite to form the popliteal vein
- – Once this enters the thigh, it is known as the femoral vein
- – Once this passes underneath the inguinal ligament, it is known as the external iliac vein
- The deep vein of the thigh drains blood from the thigh muscles
- Empties into the distal segment of the femoral vein
What is the flow of venous blood?
Flows from the skin to the superficial veins to the deep veins
- Within the veins are valves that prevent back flow of blood
What are varicose veins?
If the valves that prevent back flow of blood between the deep and superficial veins are incompetent, then blood can flow back into superficial veins
- This results in an increase intra-luminal pressure, which the veins cannot withstand
- – Causes them to become dilated and torturous
- – This is varicose veins
- Soft tissue changes can occur with chronic varicose veins
- – The pressure in the system rises
- – This damages the cells, causing blood to extrude into the skin
Which structures are found behind the medial malleolus?
Tom, Dick And Nervous Harry
- Tibialis posterior
- Flexor Digitorum longus
- Tibial Artery
- Tibial Nerve
- Flexor Hallucis longus
What is ageing and when does it begin?
- A loss of cells
- A reduction in the cell’s ability to repair
- Increased genetic mutations
- Begins when adulthood is reached
What are the consequences of ageing?
- Loss of muscle strength and endurance
- Loss of bone strength
- Increased fall risk
- Increased fracture risk
- Reduction in ability to perform activities of daily living
What factors can accelerate bone loss?
- Low reproductive hormone levels
- Poor calcium and/or vitamin D status
- Inactivity
- Endocrine or GI pathologies
What are the effects of ageing on muscle?
- Sarcopenia (loss of muscle mass due to loss of muscle fibres and reduced muscle cross-sectional area)
- Loss of muscle contractility
- Loss of neuronal innervation
What are bisphosphonates and how do they act?
- Anti-resorptive agents
- Affect osteoclasts
- Effect on bone: decrease bone turnover, increase bone mineralisation, minimal effect on bone volume
- They are taken up by osteoclasts, causing inactivation of osteoclasts
What are the clinical features of osteoarthritis?
- Pain
- Stiffness
- Deformity
- Joint swelling
What are the radiological features of osteoarthritis?
- Decreased joint space
- Sclerosis
- Osteophytes
- Bone cysts
How can osteoarthritis be treated?
Non-operative: - Weight loss - Exercise/physiotherapy - Analgesia/NSAIDs - Joint infection Operative - Arthroscopy - Osteotomies - Arthrodesis - Arthroplasty
What can the femoral artery be used for clinically?
A site for insertion of catheter to gain access to left side of heart
What is intermittent claudication?
- Pain on walking that is relieved by rest
- Build up of atherosclerotic plaque
- Same risk factors as for coronary artery disease
- Limits blood flow to muscles (ischaemia and pain)
What are the signs of poor perfusion?
- Lack of hair
- Skin problems
- Ulcers
- Infection
- Skin necrosis
- Loss of pulses
- Cold to touch
What is a popliteal aneurysm?
Abnormal dilatation of popliteal artery
- Oedema and pain in popliteal fossa
- Mass with palpable pulsation
How could the popliteal artery be damaged?
By fracture of the distal femur or dislocation of the knee
What assists venous return?
Contraction of the calf muscles
- Contracted muscles compress the deep veins and propel blood to the heart
- The blood pushed downwards will cause the lower valve to close, preventing blood flow away from the heart
