Gluteal Region and Posterior Thigh Flashcards
What four general motions are performed by the gluteal and posterior thigh muscles?
Extension, abduction, medial, and lateral rotation of the leg at the hip
What is the purpose of the sacrospinous and sacrotuberous ligaments?
These stabilize the sacrum so that the sacrum does not pivot forward due to the weight of the upper body transmitting down the spine.
What ligament separates the greater sciatic foramen and the lesser sciatic foramen? What forms the medial border of these foramen?
The sacrospinous ligament separates the two and the sacrotuberous ligament forms the medial border.
What is the most superficial gluteal muscle and what innervates it? What does the muscle do?
Gluteus maximus, innervated by the inferior gluteal nerve. It extends the leg at the hip, laterally rotates the leg, and assists in abduction.
Name six muscles that are immediately deep to the gluteus maximus.
- Gluteus medius
- Gluteus minimus
- Piriformis
- Quadratus femoris
- Obturator internus
- Gemelli
What is the importance of the piriformis muscle?
It marks the border of the superior gluteal muscles.
Where does the piriformis muscle originate and what is its insertion? What does the muscle do?
The piriformis arises from the anterior aspect of the second to the fourth segments of the sacrum, emerges through the greater sciatic foramen, and passes inferolaterally to attach to the greater trochanter of the femur. It is a lateral rotator of the leg at the thigh and helps hold the femoral head into the acetabulum.
Name six structures that emerge to the gluteal region through the greater sciatic foramen along the inferior border of the piriformis muscle.
- Inferior gluteal vessls
- Inferior gluteal nerve
- Sciatic nerve
- Posterior femoral cutaneous nerve
- Pudendal nerve
- Internal pudendal vessels
What do the gluteus minimus and medius muscles do?
Abduct the thigh and stabilize the pelvis during walking.
What can happen if someone has an injury to the superior gluteal nerve? What test is used clinically to spot this?
The superior gluteal nerve innervates the gluteus medius and minimus. If injured the patient’s hips will be abnormally pushed upwards on the side of the grounded foot while walking. If this is seen then it is called a “positive Trendelenburg test.”
Where in relation to the piriformis are the gluteus medius and minimus?
Superior and lateral
What happens to the nerves and vessels that enter the glut region superior to the piriformis?
They continue laterally in the fascial plane between the gluteus medius and minimus to supply the tensor fascia lata muscle.
How does the sciatic nerve enter the gluteal region?
Through the greater sciatic foramen inferior to the piriformis muscle.
The sciatic nerve is composed of two major nerves. At the popliteal fossa the medial component turns into the _______ nerve and the lateral component turns into the ______ _______ nerve.
medial - tibial
lateral - common peroneal
What muscles do the sciatic nerve innervate?
Hamstring muscles and all the muscles below the knee, including the sole of the foot
The quadratus femoris muscle passes from the ________ _______ to the femur.
ischial tuberosity
What nerve innervates the gluteus maximus?
Inferior gluteal nerve
What is the major cutaneous sensory nerve for the posterior thigh? How does it enter the gluteal region?
Posterior femoral cutaneous nerve. Enters through the greater sciatic foramen.
Where does the sciatic nerve arise from? How does it enter the gluteal region?
Ventral primary rami of L4 through S3. Enters glut region through the greater sciatic foramen inferior to the piriformis.
Which nerve innervates the hamstring muscles? What is the exception?
The tibial (medial) division of the sciatic nerve - except for the short head of the biceps femoris, a hamstring muscle, is innervated instead by the common peroneal nerve (lateral division).
Describe how damage to the sciatic nerve would change a person’s gait. What is a common term for this?
It would cause someone to lift the swing leg excessively high at the hip due to the inability to dorsiflex the foot - an attempt to keep the foot from dragging. Called “foot drop.”
*Note, an injury more distally in the peroneal nerve would have the same effect.
From what artery does the superior gluteal artery arise from and through what does it enter the gluteal region?
Arises from the internal iliac artery and enters the glut region through the greater sciatic foramen superior to the piriformis (hence the name superior glut artery)
What happens to the superior gluteal artery after it enters the gluteal region?
It runs deep to the gluteus maximus muscle and divides into a superficial branch that supplies the gluteus maximus and a deep branch which supplies the gluteus medius, minimus, and the tensor fascia lata.
From what artery does the inferior gluteal artery arise from and through what does it enter the gluteal region?
It arises from the internal iliac aftery and enters the gluteal region through the greater sciatic foramen inferior to the piriformis.
What does the inferior gluteal artery supply?
Gluteus maximus, the lateral rotators of the hip, and the hamstrings
The iliotibial tract is a thickening of the ______ ______ that stretches on the lateral leg from the ________ of the ________ to the ______ ______ ______.
the IT tract is a thickening of the fascia lata that stretches from the crest of the ileum to the lateral tibial condyle.
What is the gluteal aponeurosis?
A thickening of the fascia lata that extends distally from the iliac crest
In which quadrant of the gluteal region should you give an injection?
Superolateral quadrant.
What is piriformis syndrome?
When the piriformis muscle irritates and puts pressure on the sciatic nerve, causing pain in the buttocks or along the course of the nerve (from the lower back radiating down the posterior thigh).
“Fat wallet syndrome”
Name the four hamstring muscles.
- Semimembranosus
- Semitendinosus
- Biceps femoris (2 heads)
- Ischiocondylar portion of the adductor magnus muscle
Where do the hamstring muscles arise from? What is the exception?
From the ischial tuberosity except for the short head of the biceps femoris
What do the hamstring muscles do?
Extend the thigh and flex the knee
What supplies blood to the hamstring muscles?
Three perforating branches of the deep femoral artery.
What makes up the roof of the popliteal fossa?
The overlying skin, superficial fascia, and fascia lata
What forms the superior, lateral, medial, and inferior boundaries of the popliteal fossa?
The hamstring muscles make up the superior boundary.
Biceps femoris forms the lateral boundary.
Semitendinosis and semimembranosus muscles form the medial boundary.
The two gastrocnemius heads form the inferior boundary.
To what bones does the popliteus muscle connect?
Lateral femoral condyle and posterior medial aspect of the tibia.
Name the five major branches of the popliteal artery.
- Superior lateral genicular artery
- Superior middle genicular artery
- Middle genicular artery (enters into the knee joint)
- Inferior lateral genicuar artery
- Inferior medial genicular artery
List the contents of the popliteal fossa (6).
- Popliteal artery
- Popliteal vein (small saphenous vein empties into it)
- Tibial nerve
- Peroneal nerve
- Medial sural cutaneous nerve (a branch of the tibial nerve that runs alongside the small saphenous vein)
- Lateral sural cutaneous nerve (a branch of the peroneal nerve)
What is bursitis and what are two common locations in the hip region?
Inflammation of the bursae sacs due to repeated friction, stress, and inflammation. Commonly seen in the trochanteric bursa and ischial bursa.
What syndrome causes compression of the sciatic nerve?
Piriformis syndrome. Piriformis muscle spasms, compressing the nerve.
Weakening or loss of the popliteal pulse is a sign of _____?
Femoral artery obstruction.
What two serious injuries are possible in the popliteal artery?
- Popliteal aneurysm (can be diagnosed by abnormal sounds heard with a stethoscope).
- Arteriovenous fistula (communication between artery and vein caused by an injury to one or both).
What effect would injury to the tibial nerve have?
Loss of plantarflexion of the foot, loss of plantar sensation, and loss of flexion of the leg.
