Pelvic Girdle And Lower Limb

The femoral nerve innervates the anterior compartment of the thigh. This nerve is responsible for supplying motor fibers to the muscles in the front of the thigh, including the quadriceps muscles. It also provides sensory innervation to the skin on the front and inner side of the thigh. The other nerves listed, such as the tibial nerve, obturator nerve, common fibular nerve, and inferior gluteal nerve, do not innervate the anterior compartment of the thigh.

The correct answer is the femoral nerve. The femoral nerve is responsible for innervating the sartorius muscle. This muscle is located in the anterior compartment of the thigh and is involved in flexing, abducting, and rotating the hip joint. The femoral nerve originates from the lumbar plexus and provides motor and sensory innervation to the muscles and skin of the anterior thigh and medial leg.

The pectineus muscle is located in the hip and thigh region. It functions to flex the hip joint, medially rotate the hip, adduct the hip, and internally rotate the hip. However, it does not have any direct action on the knee joint, such as knee flexion. Therefore, knee flexion is NOT an action of the pectineus muscle.

The quadratus femoris muscle inserts on the quadrate tubercle of the hip.

The rectus femoris muscle originates at the AIIS (anterior inferior iliac spine). This is a bony projection located on the anterior surface of the ilium, which is part of the hip bone. The rectus femoris is one of the four muscles that make up the quadriceps group in the thigh. It crosses both the hip and knee joints, allowing it to flex the hip and extend the knee. Therefore, the rectus femoris is the correct answer as it originates at the AIIS.

The anterior superior iliac spine (ASIS) is not an origin of the gluteus maximus muscle. The gluteus maximus originates from the iliac crest, posterior gluteal line, sacrum, and coccyx. The ASIS is a bony prominence located at the front of the iliac crest, but it is not a point of origin for the gluteus maximus muscle.

The vastus medialis is a muscle that is involved in stabilizing the knee joint. It helps to resist the lateral pull of the quad group, which helps in maintaining proper alignment of the knee. During injury, the vastus medialis often rapidly wastes, meaning it can become weaker and lose muscle mass. It also opposes the Q angle, which is the angle formed between the quadriceps muscle and the patellar tendon. However, it does not flex the knee. Flexion of the knee is primarily performed by the hamstrings and gastrocnemius muscles.

The popliteus muscle originates on the lateral femoral condyle, the arcuate ligaments, and the knee capsule. It inserts on the posterior and proximal tibia. However, it does not medially rotate the femur.

The semimembranosus muscle originates at the ischial tuberosity, inserts on the medial condyle of the knee, and flexes the knee. It is innervated by the tibial nerve. However, it does not insert at pes ancerineus.

The given statement is not true because the lateral collateral ligament (LCL) is not commonly injured during ACL ruptures. The LCL is a separate ligament from the joint capsule, it inserts on the fibular head, and it resists lateral shear of the tibia on the femur. It is also cord-like in its structure. However, ACL ruptures primarily involve damage to the anterior cruciate ligament, not the LCL.

The popliteus muscle is responsible for unlocking the knee joint by countering femoral medial rotation. It produces relative femoral lateral rotation and assists the ACL in resisting posterior tibial glide. It also flexes the knee. However, it does not produce medial rotation of the femur.

The adductor magnus is capable of producing hip extension. It is a large muscle located in the inner thigh region. When it contracts, it pulls the thigh bone (femur) towards the back, resulting in hip extension. The other muscles listed, such as pectineus, adductor longus, adductor brevis, and gracilis, are primarily responsible for hip adduction, which is the movement of bringing the thigh towards the midline of the body. Therefore, they do not produce hip extension.

The piriformis muscle originates on the lateral sacral surface and inserts on the greater trochanter. It is innervated by ventral rami. It is known to both abduct and adduct the hip. However, it does not medially rotate the hip.

The gluteus minimus is a muscle that originates on the lateral ilium and inserts on the iliotibial band. It is innervated by the superior gluteal nerve, not the inferior gluteal nerve. This muscle is responsible for hip abduction and can also medially and laterally rotate the hip.

The anterior collateral ligament (ACL) is responsible for stabilizing the knee joint and preventing excessive forward movement of the tibia. It is composed of fibers that run from the lateral femoral condyle to the medial tibial plateau, which means its fibers run lateral to medial. The ACL does not resist posterior shear of the tibia, as it primarily functions to prevent anterior translation of the tibia. Additionally, the ACL has limited ability to heal itself due to its poor blood supply.

The psoas minor is a muscle that originates at the sides of T12-L1 and inserts at the iliopectineal eminence. It does not insert at the lesser trochanter. It is responsible for producing hip flexion.

The rectus femoris is a muscle located in the front of the thigh. It is responsible for two main actions: hip flexion and knee extension. Hip lateral rotation and hip abduction are not actions of the rectus femoris. However, hip medial rotation is also not an action of the rectus femoris. Therefore, the correct answer is hip medial rotation.

The vastus medialis originates from the distal 1/2 of the intertrochanteric line, the medial linea aspera, the proximal 2/3 of the medial supracondylar ridge, and the tendon of adductor magnus. It does not originate from inferior to the greater trochanter.

The anterior knee is not innervated by the L3 dermatome. The correct innervation for the anterior knee is the L4 dermatome. The dermatomes are specific regions of the skin that are innervated by different spinal nerves. In this case, the other statements are true as the lateral aspect of the foot is innervated by the S1 dermatome, the lateral leg is innervated by the L5 dermatome, the hip is innervated by the L2 dermatome, and the posterior thigh is innervated by the S2 dermatome.

The medial meniscus does not anchor medially. It is a C-shaped structure located on the inner side of the knee joint, between the femur and tibia bones. Its main functions include acting as a shock absorber, providing stability to the knee joint, and distributing forces during movement. However, it does not anchor medially, as it is not attached to the medial side of the knee joint.