Design of a semi-automatic passive knee mobilizer for lower limb rehabilitation

Abstract: Physical rehabilitation is a vital component for the recovery of patients with knee injuries or after a surgical procedure. Part of the rehabilitation treatment includes manual therapy and the use of assistive devices, all these elements play a crucial role in the functional prognosis of the patient. In the context of knee rehabilitation, physical therapists need to find more effective methods and treatments to optimize the final result in terms of function and quality of life in patients with an injury. Hence, in addition to conventional therapies techniques, the introduction of other devices has become an effective strategy to enhance therapeutic outcomes.In this regard, knee mobilizers are devices specifically designed to facilitate and control joint movement during the rehabilitation process. These devices play an important role in providing support and stability, thus contributing to a more effective recovery.There are an important variety of mobilizers with different characteristics each. However, this kind of assistive machines are too expensive for patients and rehabilitation clinics, with poor availability for some parts of the Metropolitan Area of Guadalajara and, sometimes, it’s difficult to adapt their features for patients with different anthropometric characteristics and treatment goals. This lack of adaptability and availability represent an opportunity to develop an assistive device that covers the needs mentioned above. Hence, this project aims to design a passive knee mobilizer to enhance the results of rehabilitation in patients with lower limb disabilities and post-operative procedures. The initiative addresses a fundamental challenge, which is the lack of independence and mobility among this population. The design criteria for this device included anthropometric measurements, interviews with physiotherapists and patients and a systematic literature review. During the design process it was important to select the proper materials, some of the characteristics taken into consideration were these: durability, maintenance, comfort, and cost.Some of the design implementations of this product included an adjustable limb holder to adapt the arm height for pediatric and adult users, a special seat that allows patients to shift their position to ensure the rehabilitation of both knees. Finally, the adaptation of a linear actuator for passive therapy. This machine is remotely controlled so that the physiotherapist can adjust it according to the patient's needs. Finally, it’s important to mention that the design of this product was based on local regulations and international standards. For example, ISO 13485, which outlines Quality Management Systems for Medical Devices and Mexican Official Normatives.

Keywords: Semi-automatic, lower limb, rehabilitation, knee mobilizer, device

DOI: 10.54941/ahfe1004855

Cite this paper:

​