(I’m taking a break from infanticide because school).
The quadriceps femoris muscle group is made up of the rectus femoris, vastus medialis, intermedialius, and lateralis. Rectus femoris comes from the anterior inferior iliac spine, and the others come from the femur. All of them come together in a polygamous hippie marriage via the patellar ligament and attach on the tibial tuberosity. These polygamous hippies are extensors. They are useful for when you need to extend your knee to kick a real hippie.
The hamstrings are made up of biceps femoris, semimembranosus, and semitendonosus, all of which begin at the ischial tuberosity, except for the short head of biceps femoris because he’s a fucking asshole. Come on, biceps femoris. Are you two muscles or are you one? Or are you some sort of freaky two-headed Forbidden Forest guard? Figure yourself out. Anyway, semimembranosus attaches at the posterior-proximal medial tibia, in an area aptly named “groove for the semimembranosus.” The semitendonosus attaches at some vague point on the posterior proximal tibia just south of the tibial plateau. If you can find where it attaches, you win science.
At their attachments points, both heads of the biceps femoris finally reconcile their freaky half-twin dual-head issues and come together on the fibular head. The hamstrings are antagonists to the quads. They can extend, but their main function is flexion. This is useful when running away after kicking the aforementioned hippie.
The Sartorius is a really long muscle that runs from the anterior superior iliac spine down to the medial side of the tibial anterior crest. It flexes the leg, but more importantly, when you sit cross-legged, it’s the muscle that shows on the inside of your thighs and can make you feel in shape when you haven’t been on a proper run in months.
Gastrocnemius is the muscle that shapes the femoral condyles. The lateral head attaches at the lateral femoral condyle and lateral epicondyle just above the insertion for popliteus, and the medial head attaches at the medial femoral condyle. The two heads come together in holy matrimony via the Achilles tendon. The job of gastrocnemius is to flex the foot and also to sound like some disgusting stomach aliment.