Modified Ashworth Scale (MAS) model based on clinical data measurement towards quantitative evaluation of upper limb spasticity

Spasticity is common symptom presented amongst people with sensorimotor disabilities. Imbalanced signals from the central nervous systems (CNS) which are composed of the brain and spinal cord to the muscles ultimately leading to the injury and death of motor neurons. In clinical practice, the therapist assesses muscle spasticity using a standard assessment tool like Modified Ashworth Scale (MAS), Modified Tardiue Scale (MTS) or Fugl-Meyer Assessment (FMA). This is done subjectively based on the experience and perception of the therapist subjected to the patient fatigue level and body posture. However, the inconsistency in the assessment is prevalent and could affect the efficacy of the rehabilitation process. Thus, the aim of this paper is to describe the methodology of data collection and the quantitative model of MAS developed to satisfy its description. Two subjects with MAS of 2 and 3 spasticity levels were involved in the clinical data measurement. Their level of spasticity was verified by expert therapist using current practice. Data collection was established using mechanical system equipped with data acquisition system and LABVIEW software. The procedure engaged repeated series of flexion of the affected arm that was moved against the platform using a lever mechanism and performed by the therapist. The data was then analyzed to investigate the characteristics of spasticity signal in correspondence to the MAS description. Experimental results revealed that the methodology used to quantify spasticity satisfied the MAS tool requirement according to the description. Therefore, the result is crucial and useful towards the development of formal spasticity quantification model

Gripping motion of artificial hand using EMG signal

Electromyogram (EMG) generates small signal amplitude upon muscle contraction. It is difficult to distinguish the significance of its EMG response but yet its control feasibility has been proven by many research. In this paper, the feasibility of EMG based artificial hand utilizing conventional EMG sensor was put into study. Instead of performing complex processing which may exponentially increase the cost of EMG artificial hand, the concept proposed in this paper, utilizes simple threshold activation key. The rest of the control specification is dealt with force sensor feedback. From this study, it is proven that using conventional EMG sensor to control an artificial hand is feasible to perform simple task. However, further study is required to enhance the reliability of the system

Leisure time physical activity participation in individuals with spinal cord injury in Malaysia: barriers to exercise

Study design: Cross-sectional. Objectives: An epidemiological study describing leisure time physical activities (LTPA) and the associations of barriers, sociodemographic and injury characteristics to moderate-vigorous aerobic exercise participation among individuals with spinal cord injury (SCI) in a developing Southeast Asian country. Setting: SCI community in Malaysia. Methods: The study sample consisted of 70 participants with SCI. Questionnaires were distributed containing an abbreviated Physical Activity Scale for Individuals with Physical Disabilities (items 2–6) and the Barriers to Exercise Scale using a 5-tier Likert format. Statistical analyses were χ 2 tests, odds ratios, and binary forward stepwise logistic regression to assess the association and to predict factors related to participation in moderate-vigorous intensity aerobic exercise (items 4 and 5). Results: Seventy-three percent of the study sample did not participate in any form of moderate or vigorous LTPA. The top three barriers to undertaking LTPA (strongly agree and agree descriptors) were expensive exercise equipment (54%), pain (37%) and inaccessible facilities (36%). Participants over the age of 35 years, ethnicity, health concerns, perceiving exercise as difficult and indicating lack of transport were significantly different (p < 0.05) between participation and non-participation in moderate-vigorous aerobic exercise type of LTPA. Age, ethnicity, indicated health concerns and lack of transport were the significant predictors in likelihood of participating in moderate-vigorous LTPA (p < 0.1). Conclusion: The issues raised depicted barriers within the intrapersonal (health concerns, exercising is too difficult, pain while exercising, age more than 35), interpersonal (different ethnicity), community (expensive exercise equipment), and policy levels (lack of or poor access to transportation, inaccessible facilities) that prevent LTPA participation

Clasp-Knife Model of Muscle Spasticity for Simulation of Robot-Human Interaction

The objective of this research was to replicate the muscle tone moment feedback of elbow upon passive mobilization and classify them based on modified ashworth scale criterion using a mathematical model. The proposed model enables the visualization of muscle tone pattern for robotic interaction simulation. A concurrent muscle tone model necessitates a jerk effect to fully replicate the catch and release effect, also known as, clasp-knife phenomenon of muscle tone feedback. However, the research of passive mobilization control interaction between robot and subject does not emulate such phenomenon. Thus, the model was improvised to replicate the clasp-knife phenomenon according to the robot's gross kinematics and dynamics. The model was designed based on the quantitative pattern of muscle tone feedback from subject with spasticity. The simulated model was then correlated to clinical measures using similar kinematic and dynamic input. The velocity dynamic input was splined to obtain the velocity trend without the jerk effect. The results obtained from the proposed model were relatively promising with an overall (n=9× 4) linear (Pearson) correlated average of -r=0.8348 for nine subjects with correlation significant at the 0.01 level (p< 0.01) and five of them presented a distinctive clasp-knife phenomenon with correlation average of -r=0.8631. © 2018 IEEE

Modified Ashworth Scale (MAS) integrated adaptive impedance control framework for upper extremity training platform

Robotic training platform are sought out for their promising therapeutic assistance. However, distinctive advancement has yet to resolve the monotonous and lopsided aspect of current system. Thus, this paper proposes the integration of Modified Ashworth Scale (MAS)-based assessment with dynamic impedance control model, presenting an artificial compliance within the robotic assisted training platform control framework. This enhancement is hypothesised to allow better accommodation of subject’s user input under specified training regimen. Feasibility study was verified via simulation of acceleration-based impedance model under MAS 0 and 1+ contraints for linear forward motion training regimen involving elbow extension