Stephanie L. Carey

Compensatory movements of transradial prosthesis users during common tasks

BACKGROUND Recent studies have documented motions of the upper limbs of healthy subjects during activities of daily living. The aim of this study was to investigate compensatory motions of the upper extremity and torso during tasks for transradial prosthesis users and to determine if bracing simulates prosthesis use. METHODS Seven transradial myoelectric prosthesis users and 10 non-amputee volunteers performed four common tasks. Bracing was used to simulate the use of a transradial prosthesis by the non-amputee subjects. Range of motion of the glenohumeral (shoulder) joint, elbow joint and torso were calculated from optical motion analysis data. The motions between the non-braced, braced and transradial prosthesis user groups were statistically compared. Degree of asymmetry between the affected and unaffected arm was computed for the bilateral tasks. FINDINGS Myoelectric transradial prosthesis users compensate for lack of wrist and forearm movement differently depending on the task. Compensatory motion in torso bending occurs while opening a door. For the box lift task, prosthesis users rely more on the sound arm and torso bending. While drinking from a cup, decreasing flexion of the glenohumeral joint and increasing elbow flexion was shown while using a prosthesis. While turning a steering wheel, prosthesis users are similar to non-amputee subjects. INTERPRETATION By looking at the compensatory motions caused by limiting forearm and wrist movement, a greater understanding of the problems with transradial prosthetic design can be developed. Although bracing intact subjects showed similar mechanisms of compensation in most tasks, the magnitude of compensation was greater for prosthesis users.

Differences in myoelectric and body-powered upper-limb prostheses: Systematic literature review.

The choice of a myoelectric or body-powered upper-limb prosthesis can be determined using factors including control, function, feedback, cosmesis, and rejection. Although body-powered and myoelectric control strategies offer unique functions, many prosthesis users must choose one. A systematic review was conducted to determine differences between myoelectric and body-powered prostheses to inform evidence-based clinical practice regarding prescription of these devices and training of users. A search of 9 databases identified 462 unique publications. Ultimately, 31 of them were included and 11 empirical evidence statements were developed. Conflicting evidence has been found in terms of the relative functional performance of body-powered and myoelectric prostheses. Body-powered prostheses have been shown to have advantages in durability, training time, frequency of adjustment, maintenance, and feedback; however, they could still benefit from improvements of control. Myoelectric prostheses have been shown to improve cosmesis and phantom-limb pain and are more accepted for light=intensity work. Currently, evidence is insufficient to conclude that either system provides a significant general advantage. Prosthetic selection should be based on a patients individual needs and include personal preferences, prosthetic experience, and functional needs. This work demonstrates that there is a lack of empirical evidence regarding functional differences in upper-limb prostheses.

Kinematic evaluation of terminal devices for kayaking with upper extremity amputation

This study evaluates the averaged kinematic motion of kayak paddling of two expert kayakers under three conditions (no prosthesis, pseudo-prosthesis with TRS kayak hand, and pseudo-prosthesis with USF kayak hand) compared with the kinematic motion of kayak paddling of individuals with upper limb amputation (transradial and transhumeral levels) using the same terminal devices. The TRS kayak hand was reportedly easier to apply to the paddle and more forgiving of technical errors in paddling form, whereas the USF hand maintained firm mediolateral grasp but demanded a more correct paddling form. The TRS hand is commercially available, easy to use, and currently the go-to hand for this activity. Both kayak hands would facilitate beginning kayak training or a return to kayaking.

Kinematic Comparison of Myoelectric and Body Powered Prostheses While Performing Common Activities

This study examined the kinematic differences of a bilateral transradial amputee using myoelectric and body-powered prostheses during select activities of daily living. First in harness suspended, body powered then self-suspended externally powered prostheses, the subjects shoulder and elbow joint movements were calculated and compared while completing an elbow range of motion test, simulated drinking from an empty cup, and opening a door. In this case, body-powered prostheses allowed for greater range of elbow flexion but required more shoulder flexion to complete the tasks that required continuous grasp. While using myoelectric prostheses, the user was able to compensate for limited elbow flexion by flexing the shoulder.

Differences in knee flexion between the Genium and C-Leg microprocessor knees while walking on level ground and ramps

BACKGROUND Microprocessor knees have improved the gait and functional abilities of persons with transfemoral amputation. The Genium prosthetic knee offers an advanced sensor and control system designed to decrease impairment by: allowing greater stance phase flexion, easing transitions between gait phases, and compensating for changes in terrain. The aim of this study was to determine differences between the knee flexion angle of persons using the Genium knee, the C-Leg knee, and non-amputee controls; and to evaluate the impact the prostheses on gait and level of impairment of the user. METHODS This study used a randomized experimental crossover of persons with transfemoral amputation using the Genium and C-Leg microprocessor knees (n=25), with an observational sample of non-amputee controls (n=5). Gait analysis by 3D motion tracking of subjects ambulating at different speeds on level ground and on 5° and 10° ramps was completed. FINDINGS Use of the Genium resulted in a significant increase in peak knee flexion for swing (5°, p<0.01, d=0.34) and stance (2°, p<0.01, d=0.19) phases relative to C-Leg use. There was a high degree of variability between subjects, and significant differences still remain between the Genium group and the control groups knee flexion angles for most speeds and slopes. INTERPRETATION The Genium knee generally increases flexion in swing and stance, potentially decreasing the level of impairment for persons with transfemoral amputation. This study demonstrates functional differences between the C-Leg and Genium knees to help prosthetists determine if the Genium will provide functional benefits to individual patients.

Design and fabrication of a passive-function, cylindrical grasp terminal device

To assist upper extremity amputees with achieving stable grasps of cylindrical tools, this article describes the development and testing of a prosthetic device for recreational kayak paddling. Initial development included participation of a non-amputee expert kayakist. Subsequent testing of the device used a pseudo-prosthesis for testing on a non-amputee subject, followed by qualitative feedback on the device from a unilateral transradial amputee. The device was evaluated by exploring whether subjects could independently don the terminal device, apply the paddle and use it in a pool and on a river. A semi-hinged, two hemi-cylinder sleeve was designed to be fitted onto a kayak paddle. The terminal devices frame, a second (larger) semi-hinged two hemi-cylinder sleeve, attached the device to the prosthesis. This second sleeve had internal edges that prevent lateral shifting. This component allowed smooth paddle rotation while preventing lateral shift and maintaining grasp. The non-amputee subject was successful at donning the pseudo-prosthesis and paddling. Similarly, the amputee subject was also able to don the prosthesis and paddle using the device. The design reported here is a viable option for fabricating a cylindrical grasp, passive function terminal device for kayaking. It is adaptable to other cylindrical grasp functions such as lifting an exercise weight.

Perceived differences Between the Genium and the c-LeG m icro Processor Prosthetic Knees in Prosthetic-reLated function and QuaLity of Life

Microprocessor knees (MPKs) are a viable option for persons with transfemoral amputation (TFA). Studies have assessed biomechanics and physical function to quantify MPK functional performance. However, it is also essential to assess patient perception as part of evidence-based practice using valid and reliable measures. The Prosthesis Evaluation Questionnaire (PEQ) evaluates prosthetic-related function and quality of life. The PEQ has been used in MPK literature to compare perceptive response between C-Leg and non-microprocessor-controlled knee mechanisms. The Genium, a new MPK, has not been assessed for differences in perceived function. The purpose of this project was to report perceived differences in prosthetic function and quality of life following accommodation with a Genium compared with a C-Leg. Twenty people with TFA participated in this randomized crossover study. C-Leg users randomized to test first with their own C-Leg or a Genium then crossed over into the other condition for repeated testing. Nonknee prosthetic attributes were held constant. Participants completed the PEQ for each knee condition to compare perceived differences in prosthetic function and quality of life. Genium use resulted in significant improvements (p ≤ 0.05) in the following scales — Perceived Response, Social Burden, Utility, and WellBeing — as well as in individual items related to improved standing comfort, satisfaction with walking ability, and improved gait in tight spaces, hills, and slippery surfaces (p < 0.025). As a result of using the Genium, patients perceive improvements in prosthetic-related quality of life and function. Further, patients perceive improvements in very specific mobility functions related to ambulation on complex settings.

Robot kinematics based model to predict compensatory motion of transradial prosthesis while performing bilateral tasks

In order to perform activities of daily living (ADL), a person with an amputation(s) must use a greater than normal range of movement from other anatomical body joints to compensate for the loss of movement caused by the amputation, this is called compensatory motion. By studying the compensatory motion of prosthetic users the mechanics of how they adapt to the loss of range of motion in a given limb for can be analyzed for select tasks. The purpose of this study is to create a robotic based kinematic model that can simulate the compensatory motion of a given task using given subject data. This paper reviews the use of the model to simulate compensatory motion of a transradial amputee performing two bilateral tasks: turning a steering wheel, and lifting a box. The simulation operates by changing a set of prosthetic configurations that are represented by parameters that consist of the joint degrees of freedom (DoF) provided by each prosthesis in the set. The task information is inputted into the model by defining a trajectory which the hand or prosthesis must follow to perform the task. The inclusion of the ability to model bilateral tasks is accomplished by giving control of the proximal joints to the prosthetic side. Analysis of tasks is completed by running the simulation with prosthetic and anatomical constraints attached to the left arm of the model, the right arm maintains an anatomical configuration. By running the model through this simulation the compensatory motions can be determined. Results obtained from the model can be used to select the best prosthesis for a given user, design prostheses that are more effective at selected tasks, further analyze previous studies, or to determine areas of interest for further human study.

Development and evaluation of a dynamic virtual reality driving simulator

This paper describes the driving simulator developed at University of South Florida using the Computer Assisted Rehabilitation Environment (CAREN). This driving simulator was developed to help train individuals with spinal cord injury learn how to drive in a safe and controlled environment. The simulator includes a 180 degree projection screen and a 6 degree of freedom motion base. Two types of control options were integrated into the system: regular driving controls, which mimic the controls found in regular cars, and adaptive driving controls, which are used in vehicles modified for individuals with spinal cord injury. Testing was done with healthy individuals in order to obtain feedback about the system. Subjects completed trials with and without motion feedback, two environments (a city and a highway), and the two control options. After these trials, subjects completed surveys which included ratings and questionnaires. Results from the surveys, determined design parameters that will be implemented in the future in order to improve the driving simulator.

Robotic model for simulating upper body movement

A model of the human upper limb was developed for predicting the motion of the human upper limb while performing activities of daily living. This study focuses on the effect of a joint limit function on the ability of the model to perform human like movements. This measurement was analysed by comparing the modelled joint movements with recorded movements of subjects while drinking from a cup, opening a door, turning a steering wheel, and lifting a box. The joint limit function was tested with four weighting factors: 0.00, 0.01, 0.05, and 0.10. The model showed that, for the joint limit function used, that the best results occurred when the weighting factor was 0.00. This shows that the joint limit function had a negative effect on the ability of the model to perform human like movements.