# Evaluation of a Myoelectrical Arm for Transradial Computation in Functional Activities
## 1 Introduction  
In 2005, there were roughly 41,000 individuals who experienced limb loss at or above the wrist. In that same year, 68.6% of upper limb amputations were related to trauma [1]. In 2013, there were 10,365 upper limb amputations in the U.S., with 13.6% being at the transradial, which is between the elbow and wrist; the transhumeral, which is above the elbow but below the shoulder, or the shoulder level [1]. These data were significant when considering the amputees' quality of life and how the functionality of modern prosthetics affects their everyday tasks. Losing a hand or arm presents severe challenges, often impairing work status, independence, and quality of life. While prostheses cannot fully replicate hand function, they assist in performing basic tasks and maintaining the use of both hands [2]. This is even more significant when considering the high prosthetic rejection rate. While some studies report a prosthetic rejection rate of nearly 44% [3], a review on upper limb prosthetic rejection rates reports device abandonment in one of every five users [3]. The upper extremities consist of the shoulder girdle, arm, forearm, and hand andplay a crucial role in fine motor control and manipulative tasks. They are characterized by a high degree of mobility and dexterity, enabling both gross motor activities, such as lifting, and intricate movements, such as grasping and manipulating small objects. The greater the degree of freedom (DOFs) in the upper extremities in relation to movement, the more significant the challenge of designing a functional prosthesis [4]. Due to the variety of tasks the upper limb can perform, its dexterity and sensory capacity pose major challenges to a user performing functional tasks with a prosthesis [5]. Considering the number of individuals who experience limb loss each year and the challenges with designing a functionally sound upper limb prosthesis, it is important to evaluate the current prostheses on the market to determine their functionality and how best to design training procedures that increase user functionality. While great advances have been made in prosthesis, such as enhanced sensory and motor control through targeted reinnervation and hand transplantation, users still report low levels of satisfaction related to functionality when performing unimanual and bimanual tasks, making effective prosthesis training essential for user-prosthesis integration [6]. In the context of this research, a unimanual task is a task that requires only one hand, such as brushing teeth or writing, while a bimanual task requires two hands, such as opening a jar, putting toothpaste on the toothbrush, or tying shoelaces. A myoelectric prosthesis operates using electrical signals from muscles in the residual limb, allowing for more natural and intuitive movement compared to traditionally body-powered prostheses. These electrical signals are captured by electrodes on the skin or within the prosthetic socket, translating the user's intended movements into physical movement via the actuators in the prosthesis. Several studies have demonstrated the potential for myoelectric prostheses to increase the functional ability of transradial amputees, especially in bimanual tasks. [PERSON] and [PERSON] (2007) [7] conducted a systematic literature review and found that people using myoelectric prostheses report improvements in activities such as holding, lifting, and turning things with their articulated hands. Nevertheless, they have emphasized the need for ongoing support to address any challenges users face in transitioning from traditional prostheses to myoelectric prostheses. Similarly, [PERSON] et al. (2012) [5] conducted a randomized controlled trial comparing myoelectric and body-powered prostheses in radial amputees and found that myoelectric prosthesis users showed more improvement in gripping control and efficiency in bimanual tasks.