Proximal Lower Limb Flashcards
Femoral triangle borders and contents
The femoral triangle is a wedge-shaped area located within the superomedial aspect of the anterior thigh. It acts as a conduit for structures entering and leaving the anterior thigh.
Roof – fascia lata.
Floor – pectineus, iliopsoas, and adductor longus muscles.
Superior border – inguinal ligament (a ligament that runs from the anterior superior iliac spine to the pubic tubercle).
Lateral border – medial border of the sartorius muscle.
Medial border – medial border of the adductor longus muscle. The rest of this muscle forms part of the floor of the triangle.
The inguinal ligament acts as a flexor retinaculum, supporting the contents of the femoral triangle during flexion at the hip.
Femoral nerve – innervates the anterior compartment of the thigh, and provides sensory branches for the leg and foot.
Femoral artery – responsible for the majority of the arterial supply to the lower limb.
Femoral vein – the great saphenous vein drains into the femoral vein within the triangle.
Femoral canal – contains deep lymph nodes and vessels.
Adductor canal borders and contents
The adductor canal (Hunter’s canal, subsartorial canal) is a narrow conical tunnel located in the thigh. It is approximately 15cm long, extending from the apex of the femoral triangle to the adductor hiatus of the adductor magnus. The canal serves as a passageway from structures moving between the anterior thigh and posterior leg.
Anteromedial: Sartorius.
Lateral: Vastus medialis.
Posterior: Adductor longus and adductor magnus.
The adductor canal runs from the apex of the femoral triangle to the adductor hiatus – a gap between the adductor and hamstring attachments of the adductor magnus muscle.
The adductor canal serves as a passageway for structures moving between the anterior thigh and posterior leg. It transmits the femoral artery, femoral vein (posterior to the artery), nerve to the vastus medialis and the saphenous nerve – the largest cutaneous branch of the femoral nerve. As the femoral artery and vein exit the canal, they are called the popliteal artery and vein respectively.
Psoas major attachment, insertion, function and nerve supply
Attachment/Insertion: lumbar vertebrae to lesser Trochanter of Femur
Function: Flexion of thigh at hip joint
Nerve Supply: Anterior rami/Lumbar plexus
Iliacus attachment, insertion, function and nerve supply
Attachment/Insertion: iliac fossa of pelvis to lesser Trochanter of Femur
Function: Flexion of thigh at hip joint
Nerve Supply: Femoral nerve
Sartorius attachment, insertion, function and nerve supply
Attachment/Insertion: anterior superior iliac spine to medial surface of tibia
Function: Flexion of thigh at hip joint + flexion of knee at knee joint
Nerve Supply: Femoral nerve
Recuts femoris attachment, insertion, function and nerve supply
Attachment/Insertion: anterior inferior iliac spine to quadricep femoris tendon
Function: Flexion of thigh at hip joint and extension of leg at knee joint
Nerve Supply: Femoral nerve
Vastus medialis, intermedius and lateralis attachment, insertion, function and nerve supply
Attachment/Insertion: greater trochanter and lateral lip of linea aspera (lateralis), anterior and lateral surfaces of femoral shaft (intermedius) intertrochanteric line and medial lip of linear aspera (medialis) to quadriceps femoris tendon + Patella
Function: Extension of leg at knee joint and stabilising patella
Nerve Supply: Femoral nerve
Adductor Magnus attachments, action and innervation
Attachments:
Adductor – Originates from the inferior rami of the pubis and the rami of ischium, attaches to the linea aspera of the femur.
Hamstring part – Originates from the ischial tuberosity, attaches to the adductor tubercle and medial supracondylar line of the femur.
Actions:
Adductor – Adduction and flexion of the thigh
Hamstring – Adduction and extension of the thigh.
Innervation:
Adductor – Obturator nerve (L2-L4)
Hamstring part – Tibial component of the sciatic nerve (L4-S3).
Adductor longus attachments, action and innervation
Attachments: Originates from the pubis bone of the pelvis and expands into a fan shape. It has a broad distal attachment along the linea aspera of the femur.
Actions: Adduction of the thigh.
Innervation: Obturator nerve (L2-L4).
Adductor brevis attachments, action and innervation
Attachments: Originates from the body of pubis and inferior pubic rami. Attaches to the linea aspera on the posterior surface of the femur (proximal to the adductor longus attachment).
Actions: Adduction of the thigh.
Innervation: Obturator nerve (L2-L4).
Obturator externus attachments, action and innervation
Attachments: Originates from the membrane of the obturator foramen and adjacent bone. It passes under the neck of femur and attaches onto the posterior aspect of the greater trochanter.
Actions: Adduction and lateral rotation of the thigh.
Innervation: Obturator nerve (L2-L4).
Gracilis attachments, actions and innervation
Attachments: Originates from the inferior rami of the pubis and the body of the pubis. It descends down the medial aspect of the thigh and attaches to the medial surface of the tibial shaft.
Actions: Adduction of the thigh at the hip and flexion of the leg at the knee.
Innervation: Obturator nerve (L2-L4).
Biceps femoris attachments, action and innervation
Attachments: The long head originates from the ischial tuberosity of the pelvis. The short head originates from the linea aspera on posterior surface of the femur. Together, the heads form a tendon, which inserts into the head of the fibula.
Actions: Main action is flexion at the knee. It also extends the thigh at the hip, and laterally rotates at the hip and knee.
Innervation: Long head innervated by the tibial part of the sciatic nerve, whereas the short head is innervated by the common fibular part of the sciatic nerve.
Semitendinosus attachments, action and innervation
Attachments: Originates from the ischial tuberosity of the pelvis and attaches to the medial surface of the tibia.
Actions: Flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint.
Innervation: Tibial part of the sciatic nerve.
Semimembranosus attachments, action and innervation
Attachments: Originates from the ischial tuberosity (more superiorly than the origin of the semitendinosus and biceps femoris). Attaches to the medial tibial condyle.
Actions: Flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint.
Innervation: Tibial part of the sciatic nerve.
Gluteus maximus attachments, actions and innervation
The gluteus maximus is the largest of the gluteal muscles. It is also the most superficial, producing the shape of the buttocks.
Attachments: Originates from the gluteal (posterior) surface of the ilium, sacrum and coccyx. The fibres slope across the buttock at a 45 degree angle and insert onto the iliotibial tract and gluteal tuberosity of the femur.
Actions: It is the main extensor of the thigh, and assists with lateral rotation. However, it is only used when force is required, such as running or climbing.
Innervation: Inferior gluteal nerve.
Gluteus medius attachments, actions and innervation
The gluteus medius muscle is fan-shaped and lies between to the gluteus maximus and the minimus. It is similar in shape and function to the gluteus minimus.
Attachments: Originates from the gluteal surface of the ilium and inserts into the lateral surface of the greater trochanter.
Actions: Abduction and medial rotation of the lower limb. It stabilises the pelvis during locomotion, preventing ‘dropping’ of the pelvis on the contralateral side.
Innervation: Superior gluteal nerve.
Gluteus minimus attachments, actions and innervation
The gluteus minimus is the deepest and smallest of the superficial gluteal muscles. It is similar in shape and function to the gluteus medius.
Attachments: Originates from the ilium and converges to form a tendon, inserting to the anterior side of the greater trochanter.
Actions: Abduction and medial rotation of the lower limb. It stabilises the pelvis during locomotion, preventing ‘dropping’ of the pelvis on the contralateral side.
Innervation: Superior gluteal nerve.
Tensor fascia lata attachments, actions and innervation
Tensor fasciae lata is a small superficial muscle which lies towards the anterior edge of the iliac crest. It functions to tighten the fascia lata, and so abducts and medially rotates the lower limb.
Attachments: anterior superior iliac spine (ASIS) to the iliotibial tract
Actions: Assists the gluteus medius and minimus in abduction and medial rotation of the lower limb. It also plays a supportive role in the gait cycle.
Innervation: Superior gluteal nerve.
Piriformis attachments, actions and innervation
The piriformis muscle is a key landmark in the gluteal region. It is the most superior of the deep muscles.
Attachments: Originates from the anterior surface of the sacrum. The fibres travel inferiorly and laterally through the greater sciatic foramen to insert onto the greater trochanter of the femur.
Actions: Lateral rotation and abduction.
Innervation: Nerve to piriformis.
Obturator internus attachments, actions and innervation
The obturator internus forms the lateral walls of the pelvic cavity. In some texts, the obturator internus and the gemelli muscles are considered as one muscle – the triceps coxae.
Attachments: Originates from the pubis and ischium at the obturator foramen. It travels through the lesser sciatic foramen, and attaches to the greater trochanter of the femur.
Actions: Lateral rotation and abduction.
Innervation: Nerve to obturator internus.
Gemelli attachments, actions and innervation
The gemelli are two narrow and triangular muscles. They are separated by the obturator internus tendon.
Attachments: The superior gemellus muscle originates from the ischial spine, the inferior from the ischial tuberosity. They both attach to the greater trochanter of the femur.
Actions: Lateral rotation and abduction.
Innervation: The superior gemellus muscle is innervated by the nerve to obturator internus, the inferior gemellus is innervated by the nerve to quadratus femoris.
Quadratus femoris attachments, actions and innervation
The quadratus femoris is a flat, square-shaped muscle. It is the most inferior of the deep gluteal muscles, located below the gemelli and obturator internus.
Attachments: Originates from the lateral aspect of the ischial tuberosity and attaches to the quadrate tuberosity on the intertrochanteric crest.
Actions: Lateral rotation.
Innervation: Nerve to quadratus femoris.
