Training protocol for a powered shoulder prosthesis.

Abstract

The DEKA training protocol we developed includes training in skilled unilateral movements with the prosthesis. This approach represents a shift away from prosthetic rehabilitation programs that focus solely on use of the prosthesis as an assist. our view is that an advanced prosthesis, like the DEKA arm, should assume the role of a nondominant limb, which is capable of skilled activity, though generally less adept than the dominant limb. INTRODUCTION There is a scarcity of literature on rehabilitation training protocols for upper-limb prosthesis use. Seminal textbooks and articles describe protocols for training individuals to use conventional body-powered, myoelectric, or passive prosthetic devices and were written prior to the introduction of multifunction prosthetic hands and more advanced prosthetic technologies [1-3]. Furthermore, detailed descriptions of training protocols for individuals with shoulder disarticulations or forequarter amputations are particularly limited, with little emphasis on this level of amputation [4]. Two case studies described rehabilitation at this amputation level using cosmetic or body-powered prostheses with single degree of freedom (DOF) terminal devices [5-6]. In 2008, Smurr et al. published an updated training protocol for people with upper-limb amputation that highlighted the process of controls training for body-powered and myoelectric prosthesis users by level of amputation [7]. Stubblefield et al. presented an occupational therapy training protocol specific to patients undergoing targeted muscle reinnervation surgery [8]. Previously published prosthetic rehabilitation protocols do not address prosthetic training with the advanced prostheses that have become available and include multifunction hands, powered prostheses with multiple DOFs, and/or powered shoulder joints. The most widely tested advanced, multifunction prosthesis to date is the DEKA Arm, developed through the Defense Advanced Research Projects Agency's (DARPA's) Revolutionizing Prosthetics program. The DEKA Arm is now in its third generation prototype (Gen 3) and was recently approved by the Food and Drug Administration for commercial marketing. The DEKA Arm is modular and can be configured for three levels: radial configuration (RC) for people with transradial amputation, humeral configuration (HC) for people with transhumeral amputation, and shoulder configuration (SC) for people with transhumeral amputation with very short residuum and persons with amputations at the shoulder disarticulation and interscapulothoracic (forequarter) level. Features of the SC DEKA Arm with end-point control and foot controls were described in detail in three articles [9-11]. The SC Arm is shown in figure 1. Briefly, the SC Arm has 10 powered DOFs and additional passive DOFs. Prosthetic movements are customized for the user and can employ a combination of foot controls, myoelectric controls, pneumatic bladders (provided by DEKA), or other commonly available prosthetic input elements. All levels of the DEKA Arm use control inputs for the and wrist. The control scheme has dual modes enabling the user to switch between a hand mode of operation for fine motor use and an arm mode of operation to control larger gross movements of the prosthetic arm. Gross movements are operated through endpoint control, which allows simultaneous, coordinated movement of multiple joints to move the terminal device (the end point) to a desired position in space. The Department of Veterans Affairs (VA) has led a study to optimize the DEKA Arm (Optimization Study) since 2008 and is currently leading a study of home use of the device. A synopsis of the general training protocol used in the Optimization Study was presented in two articles [12-13]. Another article describing the virtual reality environment (VRE) portion of the training protocol for the DEKA Arm second generation prototype (Gen 2) reported that VRE training was particularly valuable for people with upper-limb amputation who must master a large number of controls and for those who need a structured learning environment [14]. …