S1 Practice Questions For Lab Practical

All posterior thigh muscles (except the short head of biceps femoris) originate on
ischial tuberosity. This is one of the criteria that must be satisfied in order for a
muscle to be considered a True Hamstring.

Gower's sign is when the patient walks their hands up their legs to stand rather
than using their weakened gluteal and thigh muscles. The gluteus maximus is the
primary muscle used for standing from a sitting position and is innervated by the
inferior gluteal nerve.

The short head of the biceps femoris has two distinct differences from the other
posterior thigh muscles. First, it originates from the linea aspera of the femur, not the
ischial tuberosity (thus, it is still functional in this patient). And second, the muscle is
innervated by the common fibular nerve, not the tibial nerve. Because of this, short
head of biceps femoris is not a true Hamstring.

Inferior gluteal nerve supplies the gluteus maximus. This muscle extends the
thigh, which is necessary to lift oneself from a seated position. The hamstring
muscles are also extensors of the thigh (but the tibial n. is not an answer option
here).

The Nerve to Quadratus Femoris innervates the Inferior Gemellus muscle.

Saphenous nerve, a terminal branch of femoral nerve, supplies cutaneous
innervation to the medial leg. This nerve lies next to the great saphenous vein as it
passes posteromedial to the knee, and may be damaged as the vein is harvested at
this location.

Sciatica refers to pain or paresthesia along the regions supplied of the sciatic
nerve. Piriformis syndrome is a cause of sciatica when the sciatic nerve is
compressed as it passes through or deep to the piriformis muscle. Sitting on a thick
wallet can induce this syndrome by applying extra pressure on the piriformis muscle
causing it to temporarily compress the nerve. The other causes could result in
similar symptoms, but would not be relieved by standing up.

superficial inguinal, horizontal group

vastus medialis weakness may allow for lateral subluxation of the patella, which
may lead to dislocation of the patella out of the patellar notch of the femur. This
occurs because the Q-angle (quadriceps pull angle) is putting more lateral force on
the patella (especially in females, who tend to have a greater Q-angle).

The muscle tendon that exits the pelvic cavity through the lesser sciatic foramen is the Obturator Internus. This muscle is located in the pelvic region and helps with the rotation of the hip joint. It passes through the lesser sciatic foramen, which is a small opening in the pelvis, to reach its insertion point on the femur.

Dorsalis pedis is a branch of the anterior tibial artery and it is palpable lateral to
the tendon of the extensor hallucis longus, or between the tendons of extensor
hallucis longus and extensor digitorum longus, especially with the foot held in
dorsiflexion.

The popliteal artery divides into anterior and posterior tibial arteries. The anterior
tibial artery passes through a gap at the superior end of the interosseous membrane
to move to the anterior compartment of the leg, which it supplies.

This patient has the Trendelenberg sign: his hip drops to the opposite side when
he is balancing on one leg. The superior gluteal nerve innervates the gluteus medius
and minimus muscles, which stabilize the pelvis during walking by abducting the
thigh on the supporting (balancing) leg. The lesion always occurs on the side of the
balancing leg, NOT the side to which the hip drops.

Fibularis longus tendon has a long course posterior then inferior to the lateral
malleolus (this acts like a pulley), then inserting on the 1st metatarsal plantar surface.

Ned suffers from ‘shin splints’. This is commonly due to microtears of the tibialis
anterior muscle, usually from overuse in poorly conditioned individuals. This muscle
is a strong dorsiflexor and inverter of the foot, both of which are required when you
jog.

Common fibular nerve runs posterior to the head of the fibula and wraps around
the fibular neck, and so is prone to injury if a fracture occurs at this location. The
deep fibular nerve supplies cutaneous innervation to the web of skin between the 1st
and 2nd digits (1st interdigital cleft), while the superficial fibular nerve supplies the
distal 1/3 of the lateral leg and the rest of the dorsum of the foot; thus, sensory
deficits occurs across the entire dorsum of the foot including the web between 1st-2nd
toes with a Common Fibular N. injury since this happened prior to the split into its
two terminal branches.

Lateral cutaneous nerve (from posterior division of L2-L3) supplies the lateral
thigh, it is separate from the femoral nerve, unlike the anterior cutaneous branches
of femoral nerve that supply the anterior thigh.

The biceps femoris inserts on the fibular head. The other hamstring muscles:
semitendinosus inserts as part of pes anserinus on the proximal medial tibia, and
semimembranous inserts on the medial condyle of tibia. These muscles act as
‘splints’ along both sides of the knee, and help stabilize the knee by resisting knee
rotation.

Ligation of femoral artery proximal to profunda femoris is possible because of
continued blood flow through inferior gluteal artery (a branch of internal iliac artery),
which anastomoses with medial and lateral circumflex femoral arteries and the first
perforating a. (branches of profunda femoris); blood can thus pass through this
collateral network and return through the profunda femoris to the femoral a. distal to
the ligature.