Bamboo Usage in Orthopedic: An Attempt to Reconcile Materials Properties with the Biomechanics of Human Walking Publication History: Received: June 12, 2020 Accepted: July 15, 2020 Published: July 17, 2020 Keywords: Exoskeleton, Formability, Fracture toughness, Gait, Moso bamboo Original Article Open Access Background Current exoskeletons Tis work presents a more comprehensive assessment of the use of natural materials in orthopedic application and it is a follow up on a previous paper which dealt with the use of low-cost material for exoskeletal application. Gait is fundamental to the quality of life [1]. Gait is essential to basic activities of daily living (ADLs) to one’s ability to carry out functional tasks for independent living. For person’s living with gait and balance disorders, gait abnormality can limit quality of function and create barriers on activity performance and participation [2]. Tis is particularly signifcant for the lower extremity (LE) amputee, where the major limitation is ofen the difculty with walking [2,3]. In addition, the cost of prosthetic devices essential to restore function in people with gait dysfunction is not afordable to many. Depending on the type of prosthetic leg, the cost of prosthesis can typically range from $5,000 for a basic prosthetic leg to above $70,000 for an advanced computerized prosthetic leg and exoskeletons, and the prosthesis may only last anywhere from three to fve years before requiring replacement related to conditions of wear and tear [3]. While continual adjustments and numerous replacements will be needed during the lifetime of the amputee; for the patient without health insurance, the long-term costs associated with prosthetic care may not be afordable. While prostheses are artifcial devices used to replace missing body parts, exoskeletons work in parallel with the body to assist the user in their movements. Although both devices are primarily used for rehabilitation purposes, Exoskeletons can also be used as safety equipment. Te exoskeletons that are used for safety equipment, assist workers in performing hazardous jobs with minimal * Corresponding Author: Aruoture Egoh, Department of Mechanical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; Tel: +1 850 345 7857; E-mail: aruoture1.egoh@famu.edu Citation: Carnrike T, Egoh A, Reed KS, Kalu PN (2020) Bamboo Usage in Orthopedic: An Attempt to Reconcile Materials Properties with the Biomechanics of Human Walking. Int J Phys Ther Rehab 6: 164. doi: https://doi.org/10.15344/2455- 7498/2020/164 Copyright: © 2020 Carnrike et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. injuries [4]. When used for rehabilitation purposes, the individuals in question are usually sufering from debilitating neurological or limb pathologies lacking sufcient strength, power, torque, and endurance [5]. Exoskeletons can be used to target the full body, upper extremities, and lower extremities [6]. Figures 1-4 presents the diferent types of exoskeletons used for lower extremities, and they are classifed as powered, passive, pseudo-passive, and hybrid [5,7-10]. Obviously, exoskeletons enable people with serious mobility issues to leave their wheelchairs behind. Te main issue is that the cost of a wheelchair is cheaper than an exoskeleton which is why health insurers don’t see its beneft. When the price of the exoskeletons become comparable to that of a wheelchair then insurance companies will consider these devices for personal use. Physical therapy ofces and large companies are the current exoskeleton customers. Te high cost of exoskeletons can be attributed partly to the cost of the material it is made out of. Exoskeletons currently available are typically made of Duralumin (Al-2024 T6). Other materials investigated were either too heavy (steel) or too expensive (carbon fber). In order to replace International Journal of Physical Terapy & Rehabilitation Talya Carnrike 1 , Aruoture Egoh 1* , Kischa S. Reed 2 and Peter N. Kalu 1 1 Department of Mechanical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA 2 Division of Physical Terapy, Florida A&M University, Tallahassee, FL 32307, USA Int J Phys Ter Rehab IJPTR, an open access journal ISSN: 2455-7498 Volume 6. 2020. 164 Carnrike et al., Int J Phys Ther Rehab 2020, 6: 164 https://doi.org/10.15344/2455-7498/2020/164 Abstract Background: Tis work is part of an ongoing study on the use of natural materials to provide low cost exoskeleton and orthopedic devices in general. An earlier work showed that fr, pine, oak and bamboo satisfed the requirements of the mid-stance of the Gait cycle which is about 10% of a person’s total weight. In reality, there are eight determinants of the gait cycle and they involve pelvic rotation and tilt, in addition to foot mechanics, knee mechanics and lateral displacement of pelvis. Furthermore, during walking, the peak vertical ground reaction force can rise up to 1.2 times the body weight. Terefore, any replacement exoskeleton material is expected to withstand this amount of compressive force and the rotational torques as well as possess excellent fracture toughness. Methods: Te eight determinants of the gait cycle of normal walking were analyzed with along their consideration that during walking, the peak vertical ground reaction force can rise up to 1.2 times the body weight. Te materials selection process utilized the Ashby’s procedure and consists of four steps, namely: translation, screening, ranking and documentation. Additional assessment of the fracture toughness and formability of the materials were carried out. Results: While all the natural materials satisfed the basic selection, process based on cost and weight, only oak and Moso bamboo fulflled the additional requirement of strength and formability. Oak was however eliminated due to its characteristic low fracture toughness which means that it is unable to provide the weight bearing support in the stance phase. Conclusion: All the natural materials studied satisfed the cost and weight requirements for low-cost orthopedic devices. However, only Moso bamboo with its characteristic high fracture toughness and formability can comfortably replace duralumin in exoskeleton.