Arm movement, specifically swinging, is an integral part of walking and movement for humans. Due to injuries and complex diseases, some people lose their ability to swing their arms correctly or entirely. Incorrect swinging movement or a lack of movement can negatively impact these people's lives and correlates to a high risk of fall and deteriorated gait patterns. Research has shown that providing assistance to restore the movement of the arms closer to baseline conditions can facilitate better gait recovery. To address this need, a design is proposed of a sleeve-like device that can lift the arm and then release it to mimic the version of the arm-swing movement generated while walking. This would be achieved with a system of cables and pulleys that would be actuated by an electric motor. Additionally, the frequency of the generated arm-swing will be a function of the frequency of the movement of the legs, based on a transfer function relating baseline arm movement to walking patterns obtained from previous research. The design should demonstrate the arm-swing movement at a variety of frequencies while operating on a mannequin. This will display how the device can work at multiple walking speeds to swing an actual arm. Additionally, figures and data will be generated to show the device's performance and flaws. The data should demonstrate the device's ability to perform in situations comparable to real-life walking.