## 1 Introduction  
Stroke is one of the major global health issues, with over 13 million new cases annually and representing the second leading cause of mortality and disability worldwide. According to the Global Burden of Disease Study (GBD) in 2016, there was an increase in frequency among younger groups (under 50 years old), depicting the distribution of incidence across ages. Moreover, the incidence of stroke, along with stroke-related mortality and disability, increased nearly two-fold from 1990 to 2016 [1]. According to the consequences of disability, muscle dysfunction is the predominant form of impairment following a stroke. Muscle dysfunction significantly worsens the risk of arm paralysis after a stroke and is frequently associated with increased impairment, reduced work capacity, and diminished quality of life. The accumulation of inactive muscle fibers due to dysfunction leads to abnormal muscle activation patterns, such as spastic muscle contractions, which may contribute to further muscle-related disorders [2, 3]. Consequently, individuals who have experienced a stroke affecting their arm may struggle to perform daily activities [4]. In order to restore the function of muscle fiber after a stroke, rehabilitation is necessary as a routine muscle recovery process [3, 5]. Rehabilitation refers to the combined and coordinated use of medical, social, educational, and occupational measures to retrain a person to the highest functional skills level [5]. The rehabilitation process includes assessing the patient's impairment condition, followed by further medication, training, and reassessment. The assessment is intended to observe and evaluate the patient's actual condition. Thus, a suitable training and medication program can be specifically arranged for each patient. In this regard, the assessment process is essential, as it determines the patient's actual condition at the beginning of the rehabilitation program and after several medication and training processes. Several clinical methods to assess the impairment level of post-stroke patients are currently being employed worldwide. Regarding the assessment of motorfunction, the Fugl-Meyer assessment (FMA) is a notable tool, as it provides a detailed assessment protocol with a scoring system in most human extremities. The Fugl-Meyer scale is a groundbreaking quantitative evaluative tool to measure sensorimotor stroke recovery. The motor-domain function of this tool encompasses large and small parts of the upper-lower extremities, suggesting the most comprehensive measures of motor impairment following stroke. One of the assessment components the assessment a complex motor function, such as finger movement, that is composed of a combination of complex muscles [3]. In the case of finger movement, the Fugl-Meyer assessment of the hand's upper extremity (FMA-UE) is typically selected. As shown in Table 1, this questionnaire consists of seven finger movement tasks, namely Mass Extension (ME), Mass Flexion (MF), Hook Grasp (HG), Thumb Adduction (TA), Piner Grasp (PG), Cylinder Grasp (CG), and Spherical Grasp (SG). Meanwhile, the impairment level consists of three conditions (i.e., full, partial, and none). The doctor or physiotherapist has an inherent role in the assessment. Several finger movements in FMA-UE are object-dependent tasks that require a patient to hold an object while the doctor tugs it. This mechanism in the Fugl-Meyer assessment is the conventional method that requires the doctor to observe the impairment level manually through visual and tug inspection. Nevertheless, the inherent role of a doctor in the conventional method raises another issue, i.e., inherent subjectivity, which also promotes the subjectivity of the assessment result. Consequently, this issue influences the accuracy and repeatability of the assessment score, which is particularly essential for repeated assessments in the rehabilitation process.