The seated leg curl pin load selection machine is a piece of exercise equipment that targets the muscles in the back of the legs, specifically the hamstrings. The machine typically consists of a seat with a backrest, a leg pad that is attached to a stack of weights, and a pin that can be inserted into the weight stack to select the desired resistance. To use the machine, you would adjust the seat and leg pad to fit your body size and positioning. Then, you would select the appropriate weight by inserting the pin into the weight stack at the desired resistance level. Once you are ready, you would sit on the machine with your legs positioned under the leg pad and curl your legs towards your body by flexing your knees. It is important to start with a lighter weight and gradually increase the resistance as you become stronger. Proper form and technique are also crucial to prevent injury and effectively target the muscles in the back of the legs.