Posterior Compartment and Neurovascularity

Question 1

Semitendinosus proximal and distal attachments, nerve supply and action

Answer 1

• Proximal Attachment: – Ischial Tuberosity
• Distal Attachment:

– Anteromedial Aspect Of Proximal Tibia (Along With Other Muscles forming the Pes Anserinus)

• Nerve Suply:
– Tibial Component Of The Sciatic (L5-S2, Anterior

Division) • Action:

– Flexes Knee* – Extends Hip

Question 2

Semimembranosus proximal/distal attachment and nerve supply and action

Answer 2

• PROXIMAL ATTACHMENT – ISCHIAL TUBEROSITY

• DISTAL ATTACHMENT:
– POSTERIOR ASPECT OF MEDIAL CONDYLE OF TIBIA

• NERVE SUPPLY:
– TIBIAL COMPONENT OF THE SCIATIC (L5-S2)

• ACTION:
– FLEXES KNEE* – EXTENDS HIP

Question 3

Biceps Femoris proximal/distal attachments. nerve supply and action

Answer 3

• Proximal Attachment

– Long Head - Ischial Tuberosity

– Short Head - Linea Aspera’s lateral lip & Lateral Supracondylar Line

• Distal Attachment
– Lateral Aspect Of Head Of Fibula

• Nerve Supply

– Long Head: Tibial Component Of Sciatic (S1-S3)

– Short Head: Common Peroneal Component Of Sciatic (L5-S2, Posterior Division)

• Action:
– Extend Hip (Long Head) – Flex Knee (Both Heads)*

Question 4

hamstrings collective function

Answer 4

• Collective Function

– During Swing Phase, They Arrest Knee Extension - This Avoids “Snapping Shut” Of Knee And Considerable Shock Damage

Question 5

Pes Anserinus consists of

Answer 5

semitendiosus

gracilis

sartorius

Question 6

the lumbar plexus

Answer 6

Question 7

the sacral plexus

Answer 7

Question 8

Sciatic nerve

Answer 8

Notes: From Lumbar 4-5 & Sacral 1-2-3

(C. Peroneal From Posterior Division

Tibial From Anterior Division)

Question 9

obturator nerve

Answer 9

Question 10

cutaneous innervation of the thigh

Answer 10

Question 11

Posterior thigh innervation

Answer 11

Question 12

posterior femoral cutaneous nerve

Answer 12

Question 13

LL dermatomes

Answer 13