# Evaluation of a Myoelectrical Arm for Transradial Computation in Functional Activities
## 1 Introduction
In their study, they emphasized the importance of user training and proper socket fit to maximize the benefits of myoelectric prostheses for transradial amputees. Ensuring proper fit and comfort is essential for the successful use of a myoelectric prosthetic arm, prompting the need for continued research to optimize design for a snug and pleasant fit. To facilitate device adaptation, training, and adjustment, individuals must learn how to operate these devices smoothly, highlighting the need for effective training programs and support mechanisms. Maintaining and ensuring the longevity of myoelectric prosthetic arms is also crucial, necessitating research to enhance durability and reliability to reduce repair and replacement frequency. A participant with a congenital limb difference is usually recommended directly into the outpatient prosthetic training with a myoelectric arm. The framework of the training can be broken down into four levels, with the idea of increasing task difficulty through each level to match the increased complexity of activities of daily living (ADLs). At the first level, the participant is trained to perform movements such as opening/closing the terminal device. At the second level, object manipulation is incorporated into tasks with objects of different sizes and shapes. This level also focuses on rate training and grip control to create natural movements with the myoelectric arm and to achieve good grip control, in which the patient learns how much pressure to exert with the device based on the density and durability of the object [8]. Functional tasks with increasing complexity are introduced at the third level. Functional tasks often start with basic ADLs [8]. While the participants with unilateral upper extremity amputations master one-handed techniques for ADL performance, they will be given basic bilateral tasks for their prosthesis to work with their intact limb [8]. The fourth and final level of training would cover various household tasks, community, and work reintegration [8]. Currently, few standardized tests are available for assessing upper extremity prosthesis performance in outpatient prosthetic training, with few upper limb prosthetic-specific outcome measures in number [9]. The 'Unilateral Upper Extremity Amputation: Activities of Daily Living Assessment' is a task list that the therapist uses to only qualitatively rate the task smoothness during therapy sessions [8]. The Assessment of Capacity for Myoelectric Control (ACMC) [10] focuses on the performance of a myoelectric prosthesis but lacks standardization for different types of prostheses or functional contexts. While useful for assessing task performance and dexterity, the Jebsen-Taylor Test of Hand Function [11], Box and Blocks Test [12], Nine-Hole Peg Test [13], and Southampton Hand Assessment Procedure (SHAP) [14] are not standardized for prosthetic use. More research in standardized assessment for prosthetic use is thus needed to objectively gather a core set of outcome measures, which can be assessed by using motion analysis tools. For example, the level of object manipulation can be quantified by the smoothness of hand module movement, which is calculated as the derivative of hand acceleration, and reliance on visual feedback, which can be calculated as a correlation coefficient between head movement trajectory and hand module movement trajectory. Head and hand module movement can be measured by using a marker-based motion capture tool. In addition, current research effort focuses on assessing the myoelectric arm in the lab environment, often with able-bodied participants [15; 16], which does not examine how amputees learn to use a prosthesis in actual ADLs, especially not how they learn to integrate multi-grip modes into their daily lives [17]. Nevertheless, an effective training program needs the prosthesis user to perform the tasks in the context of ADLs [18].