Every 5 minutes, a person in the U.S. loses their ability to move due to a lower limb amputation. Even the best available prostheses cannot move like biological legs, lacking the ability to actively generate movements and provide power during gait. Due to these limitations, even performing simple activities like walking and climbing stairs become very challenging for individuals with amputation. Emerging robotic leg prostheses have the potential to address these limitations. By using motors, batteries, and controls, robotic prostheses have the potential to move similarly to biological legs. However, available robotic leg prostheses controllers perform prerecorded movements that are disconnected from the user's intentions to move. Therefore, amputees have no voluntary control of their prosthetic leg. The goal of my undergraduate research is to connect the human neural systems with robotic leg prostheses to give amputees voluntary control. To accomplish this goal, I propose using non-invasive, surface electromyography, the measurement of muscle activations. Using electromyography, I can measure the muscle activations in the residual limb, the remaining part of the leg after amputation. These muscle contractions encode the user's intention to move the missing lower limb. For example, a contraction of the residual quadriceps, when the foot is off the ground, encodes the intention of the user to swing the leg forward. Based on this idea, I developed a neural controller that allows robotic prostheses to perform movements intended by the user. I tested this controller with three individuals with an above-knee amputation. The test included daily activities like walking and climbing stairs using the robotic leg prosthesis. The proposed neural controller enabled the users to walk, climb up and down stairs, stand up and sit down by controlling the prosthesis movements with their muscle contractions. This study provides new evidence that voluntary control of lower limb prosthetics is possible. Electromyography and neural control have the potential to revolutionize the field of prosthetics by giving amputees voluntary control of their prostheses.