Doctor of Philosophy

dissertationMost humans have difficulty performing precision tasks, such as writing and painting, without additional physical support(s) to help steady or offload their arm's weight. To alleviate this problem, various passive and active devices have been developed. However, such devices often have a small workspace and lack scalable gravity compensation throughout the workspace and/or diversity in their applications. This dissertation describes the development of a Spatial Active Handrest (SAHR), a large-workspace manipulation aid, to offload the weight of the user's arm and increase user's accuracy over a large three-dimensional workspace. This device has four degrees-of-freedom and allows the user to perform dexterous tasks within a large workspace that matches the workspace of a human arm when performing daily tasks. Users can move this device to a desired position and orientation using force or position inputs, or a combination of both. The SAHR converts the given input(s) to desired velocit

Development of a Wearable Mechatronic Elbow Brace for Postoperative Motion Rehabilitation

This thesis describes the development of a wearable mechatronic brace for upper limb rehabilitation that can be used at any stage of motion training after surgical reconstruction of brachial plexus nerves. The results of the mechanical design and the work completed towards finding the best torque transmission system are presented herein. As part of this mechatronic system, a customized control system was designed, tested and modified. The control strategy was improved by replacing a PID controller with a cascade controller. Although the experiments have shown that the proposed device can be successfully used for muscle training, further assessment of the device, with the help of data from the patients with brachial plexus injury (BPI), is required to improve the control strategy. Unique features of this device include the combination of adjustability and modularity, as well as the passive adjustment required to compensate for the carrying angle

The Painful Long Head of the Biceps Brachii: Nonoperative Treatment Approaches

Pain associated with the long head of the biceps (LHB) brachii seems to be increasingly recognized in the past 4 to 5 years. The LHB has long been considered a troublesome pain generator in the shoulder. Abnormality involving the LHB brachii has long been an area of debate, with Codman in 1934 even questioning the specificity of the diagnosis of biceps tendinitis. Biceps tendon abnormality is often associated with rotator cuff impingement. Shoulder pain originating from the biceps tendon can be debilitating, causing a severe decrease in shoulder function. As a result of the frequent clinical presentation of biceps pain, there is currently a great deal of interest regarding the diagnosis, treatment, and prevention of biceps abnormality. This article describes a classification system of LHB pain and discusses nonoperative treatment concepts and techniques for the painful LHB

The Effects of Wearing a Portable Media Armband on Muscle Activation of the Biceps Brachii

International Journal of Exercise Science 16(1): 1461-1470, 2023. Portable media armbands are commonly used among the physically active population. Their effect on muscle function has not been established. The purpose of this study was to determine if muscle activation of the biceps brachii is influenced by wearing a portable media armband during an elbow flexion exercise. Eighteen participants (11 males: age = 22.5 ± 2.1 years, height = 178.3 ± 5.2 cm, mass = 85.0 ± 6.5 kg; 7 females: age = 22.9 ± 2.5 years, height = 168.3 ± 5.7 cm, mass = 72.3 ± 12.2 kg) with no history of upper extremity injury volunteered for the study. Participants performed elbow flexion trials with a hand-held dumbbell with and without wearing a portable media armband. Dumbbell weight was determined by an 8-10 repetition maximum, and the condition was counterbalanced. The average concentric and eccentric phases for five trials for each condition were normalized to a maximum voluntary isometric contraction using electromyography. The independent variable was condition (with-PMAB and without-PMAB). The dependent variable was the muscle activation of the biceps brachii. Mean data for each condition were analyzed using separate paired-samples t-tests for the concentric and eccentric phases (p \u3c 0.05). Statistical analysis revealed a significant difference for the concentric phase (t17 = 2.905; p = 0.010). The with-PMAB condition elicited greater muscle activation (72.57 ± 36.31%) compared to the without-PMAB (63.67 ± 26.2%), with a medium effect size (d = 0.69). There was no statistical difference for the eccentric phase (t17 = 1.964; p = 0.066), and a small effect size (d = 0.46). The increase in muscle activation during the concentric phase is likely due to a change in the muscle properties due to the compressive force applied to the muscle fibers by the portable media armband

IISE Trans Occup Ergon Hum Factors

Background:In the literature, efficacy of passive upper limb exoskeletons has been demonstrated in reduced activity of involved muscles during overhead occupational tasks. However, there are fewer studies that have investigated the efficacy of active upper limb exoskeletons or compared them with their passive counterparts.Purpose:We aimed to use an approach simulating human-exoskeleton interactions to compare several passive and active assistance methods in an upper limb exoskeleton and to evaluate how different assistance types affect musculoskeletal loadings during overhead lifting.Methods:An upper-extremity musculoskeletal model was integrated with a five degree-of-freedom exoskeleton for virtual human-in-the-loop evaluation of exoskeleton design and control. Different assistance methods were evaluated, including spring-based activation zones and active control based on EMG, to examine their biomechanical effects on musculoskeletal loadings including interaction forces and moments, muscle activations, and joint moments and reaction forces.Results:Our modeling and simulation results suggest the effectiveness of the proposed passive and active assistance methods in reducing biomechanical loadings\u2014the upper-limb exoskeletons could reduce maximum loading on the shoulder joint by up to 46% compared to the no-exoskeleton situation. Active assistance was found to outperform the passive assistance approach. Specifically, EMG-based active assistance could assist over the whole lifting range and had a larger capability to reduce deltoid muscle activation and shoulder joint reaction force.Conclusions:We used a modeling and simulation approach to virtually evaluate various exoskeleton assistance methods without testing multiple physical prototypes and to investigate the effects of these methods on musculoskeletal loadings that cannot be measured directly or noninvasively. Our findings offer new approaches for testing methods and improving exoskeleton designs with \u201csmart\u201d controls. More research is planned to further optimize the exoskeleton control strategies and validate the simulated results in a real-life implementation.CC999999/ImCDC/Intramural CDC HHSUnited States/2022-01-27T00:00:00Z34254566PMC878993412107vault:4075

User Based Development and Test of the EXOTIC Exoskeleton:Empowering Individuals with Tetraplegia Using a Compact, Versatile, 5-DoF Upper Limb Exoskeleton Controlled through Intelligent Semi-Automated Shared Tongue Control

This paper presents the EXOTIC- a novel assistive upper limb exoskeleton for individuals with complete functional tetraplegia that provides an unprecedented level of versatility and control. The current literature on exoskeletons mainly focuses on the basic technical aspects of exoskeleton design and control while the context in which these exoskeletons should function is less or not prioritized even though it poses important technical requirements. We considered all sources of design requirements, from the basic technical functions to the real-world practical application. The EXOTIC features: (1) a compact, safe, wheelchair-mountable, easy to don and doff exoskeleton capable of facilitating multiple highly desired activities of daily living for individuals with tetraplegia; (2) a semi-automated computer vision guidance system that can be enabled by the user when relevant; (3) a tongue control interface allowing for full, volitional, and continuous control over all possible motions of the exoskeleton. The EXOTIC was tested on ten able-bodied individuals and three users with tetraplegia caused by spinal cord injury. During the tests the EXOTIC succeeded in fully assisting tasks such as drinking and picking up snacks, even for users with complete functional tetraplegia and the need for a ventilator. The users confirmed the usability of the EXOTIC

Clarinet Thumb-rest Function: The Pedagogy of Positioning and Electromyography Evidence

Clarinetists bear the weight of their instrument on their right thumb using a small metal attachment called a thumb-rest. The soprano clarinet weighs only two pounds, but many hours of playing can cause general discomfort to severe overuse injury throughout the upper right limb. There is a debate within the clarinet community about the best position of the thumb-rest, yet no quantitative research has been conducted on this issue. This document establishes a historical and modern context for the use of the clarinet thumb-rest. It reviews traditional and non-traditional medical approaches that individuals use to help clarinetists with supporting the instrument. This document presents data and analysis from an electromyography &40;EMG%41; study of 20 healthy student and professional clarinet players. It discusses current approaches to supporting the instrument with after-market products and modifications to the instruments and addresses the implications for the pedagogy of clarinet right-hand support. Surface EMG recordings of superficial muscles that control the right thumb, wrist, and arm were taken during held note and finger exercises trials at three different thumb-rest position heights. Hand size and experience level were considered. Researchers found a significant main effect of rest position in the biceps brachii, abductor pollicis brevis, abductor pollicis longus, extensor carpi radialis and flexor carpi ulnaris. There was no main effect of hand size in the muscles. Because opposing muscles had contrasting patterns of activation regardless of hand size, there is no conclusive support to change the standard position for thumb rests. Some interactions between variables such as exercise number, position, and size enrich the understanding of the biomechanics of clarinet playing. Future research avenues are proposed