Change in muscle tonus is characteristic of upper motor neuron disease. Upper limb hypertonus is mostly experienced in the flexor muscles group, causing abnormal fixed flexion of the elbow. This in turn leads to functional impairments in daily life (especially in stability while standing and walking, and in activities such as dressing), often accompanied by chronic pain. Extension of the spastic elbow is therefore a significant target goal of the rehabilitation process of these patients. This study presents the development of a simple, cheap and easy-to-use splint aimed at keeping the elbow extended. The splint is made out of cloth and plastic strips with longitudinal pockets sown into a double layer cloth surface. The splint is then wrapped and tightened around the extended elbow. The splint was applied to 30 patients with hypertonic flexed elbow. Patients were asked to keep the splint wrapped around their elbows between one to five hours a day, for a period of three weeks. They were instructed to shorten the time of use whenever they felt pain, discomfort or extended pressure on the arm. Most of the patients completed the trial as instructed and expressed their wish to carry on using it. The reported "side effects" included discomfort, feeling of pressure at the critical points and difficult self-application of the splint. The final splint model was developed based on this feedback. Its efficacy in keeping the elbow in an extended position, its low cost price and easy use makes this splint a viable and simple tool for the rehabilitation process of upper motor neuron disease patients.