PDF Lower Limb: Gluteal Region and Posterior Thigh

Flashcards covering the anatomy, muscles, innervation, and blood supply of the gluteal region and posterior thigh, useful for reviewing lecture notes.

Anterior Compartment of Thigh

A major muscle of the anterior compartment of the thigh, primarily involved in hip flexion and knee extension.

Medial Compartment of Thigh

A major muscle group of the medial compartment of the thigh, primarily involved in thigh adduction, flexion, and lateral rotation.

Dermatome

A surface area of skin supplied by a single spinal nerve and its corresponding spinal cord segment.

Ligaments of Pelvic Girdle

Ligaments (sacrotuberous and sacrospinous) that convert the greater and lesser sciatic notches of the pelvis into foramina, and help prevent sagittal rotation of the pelvis.

Greater Sciatic Foramen

Formed by the sacrotuberous and sacrospinous ligaments, it transmits structures entering and leaving the pelvis, such as the sciatic nerve.

Lesser Sciatic Foramen

Formed by the sacrotuberous and sacrospinous ligaments, it transmits structures entering and leaving the perineum, such as the pudendal nerve.

Gluteal Aponeurosis

A fascial covering over the gluteus medius muscle, continuous with the fascia latae, providing access to the fascial interval between gluteus maximus and medius.

Posterior Compartment of the Thigh

Contains muscles such as biceps femoris, semimembranosus, semitendinosus, perforating branches of deep femoral artery & vein, and the sciatic nerve.

Gluteal Muscles

The primary abductors and lateral rotators of the thigh, which also aid in thigh flexion and extension, and are organized into superficial and deep layers.

Gluteus Maximus

Originates from the ilium, sacrum, coccyx, and sacrotuberous ligament; inserts into the gluteal tuberosity and iliotibial tract; extends and laterally rotates the thigh, stabilizes the knee; innervated by the inferior gluteal nerve.

Gluteus Medius

Originates from the ilium; inserts into the greater trochanter; abducts the thigh, assists in lateral/medial thigh rotation and leveling the sacral base; innervated by the superior gluteal nerve.

Gluteus Minimus

Originates from the ilium; inserts into the anterior surface of the greater trochanter; abducts and medially rotates the thigh, assists in leveling the sacral base; innervated by the superior gluteal nerve.

Tensor Fascia Latae

Originates from the anterolateral iliac crest; inserts into the iliotibial tract; abducts, flexes, and medially rotates the thigh, maintains extended knee; innervated by the superior gluteal nerve.

Piriformis

Originates from the anterior surface of the sacrum; inserts into the greater trochanter; abducts and laterally rotates the thigh; innervated by the nerve to piriformis (S1, S2).

Gemellus Superior

Originates from the ischial spine; merges with obturator internus tendon to the trochanteric fossa; performs lateral thigh rotation and thigh abduction; innervated by the nerve to obturator internus.

Obturator Internus

Originates from the internal surface of the obturator membrane and margin of the obturator foramen; inserts into the greater trochanter; performs lateral rotation and abduction of the thigh; innervated by the nerve to obturator internus.

Gemellus Inferior

Originates from the ischial tuberosity; merges with obturator internus tendon to the trochanteric fossa; performs lateral thigh rotation and thigh abduction; innervated by the nerve to quadratus femoris.

Quadratus Femoris

Originates from the ischial tuberosity; inserts into the quadrate tubercle on the intertrochanteric crest of the femur; performs lateral thigh rotation; innervated by the nerve to quadratus femoris.

Hamstring Muscles

Muscles of the posterior thigh (excluding the short head of biceps femoris) that extend the thigh and flex the leg, including long head biceps femoris, semimembranosus, and semitendinosus.

Biceps Femoris

Long head originates from the ischial tuberosity (innervated by tibial n.) and short head originates from the linea aspera (innervated by common fibular n.); both flex and laterally rotate the leg, with the long head also extending the thigh.

Semimembranosus

Originates from the ischial tuberosity; inserts into the posterior surface of the medial condyle on the tibia; extends the thigh, flexes and medially rotates the leg; innervated by the tibial component of the sciatic nerve.

Semitendinosus

Originates from the ischial tuberosity; inserts into the medial anterior surface of the tibia; extends the thigh, flexes and medially rotates the leg; innervated by the tibial component of the sciatic nerve.

Avulsion Fracture

A type of fracture where a tendon or ligament pulls off a piece of bone, commonly seen at muscle/ligament attachment sites like the ischial tuberosity (hamstrings) or anterior superior iliac spine (sartorius).

Superior Gluteal Artery

The largest artery branching from the internal iliac artery, emerging superior to piriformis to supply gluteus maximus, medius, minimus, and tensor fascia latae.

Inferior Gluteal Artery

An artery that leaves the pelvis inferior to piriformis, supplying deep hip muscles, gluteus maximus, and superior parts of the hamstrings.

Perforating Arteries

Arteries that enter the posterior compartment to supply the hamstrings, anastomose with other perforating branches and with inferior gluteal and popliteal arteries, and supply the vastus lateralis muscle.

Cruciate Anastomosis

An anastomotic network of arteries at the hip, formed by the medial circumflex femoral artery, lateral circumflex femoral artery, inferior gluteal artery, and the 1st perforating artery.

Superior Gluteal Nerve

A nerve (L4–S1) that provides motor innervation to the gluteus medius, minimus, and tensor fascia latae, entering the gluteal region superior to the piriformis.

Trendelenburg Gait

A gait abnormality caused by a superior gluteal nerve lesion, leading to pelvic descent on the opposite side during the swing phase, compensated by leaning to the affected side.

Inferior Gluteal Nerve

A nerve (L5–S2) that provides motor innervation to the gluteus maximus, leaving the pelvis inferior to the piriformis.

Gluteus Maximus Gait/Lurch

A gait abnormality caused by an inferior gluteal nerve lesion, characterized by posterior leaning of the trunk at heel strike to keep the hip extended during the stance phase.

Sciatic Nerve

The largest peripheral nerve in the body (L4–S3), containing tibial and common fibular nerves; exits the pelvis inferior to or piercing the piriformis; supplies muscles of the posterior thigh, leg, foot, and most skin of the leg and foot.

Piriformis Syndrome

A condition where the sciatic nerve is compressed by the piriformis muscle, causing pain and paresthesia distally, often due to excess use of the piriformis.

Nerve to Quadratus Femoris

A nerve (L4-S1) that provides motor innervation to the gemellus inferior and quadratus femoris, exiting the greater sciatic foramen inferior to the piriformis.

Nerve to Obturator Internus

A nerve (L5-S2) that provides motor innervation to the obturator internus and gemellus superior, exiting the greater sciatic foramen inferior to the piriformis.

Nerve to Piriformis

A nerve (S1, S2) that provides motor innervation to the piriformis muscle, innervating it within the pelvis.

Tibial Nerve

A component of the sciatic nerve (L4–S3) that provides motor innervation to the long head of biceps femoris, semitendinosus, and semimembranosus.

Common Fibular Nerve

A component of the sciatic nerve (L4–S2) that provides motor innervation to the short head of biceps femoris.

Intragluteal Injections

The practice of administering injections into the gluteal region, typically in the superolateral quadrant, to avoid damaging the sciatic nerve.