Controlling a multi-degree of freedom upper limb prosthesis using foot controls: user experience

Abstract

Purpose: The DEKA Arm, a pre-commercial upper limb prosthesis, funded by the DARPA Revolutionizing Prosthetics Program, offers increased degrees of freedom while requiring a large number of user control inputs to operate. To address this challenge, DEKA developed prototype foot controls. Although the concept of utilizing foot controls to operate an upper limb prosthesis has been discussed for decades, only small-sized studies have been performed and no commercial product exists. The purpose of this paper is to report amputee user perspectives on using three different iterations of foot controls to operate the DEKA Arm. Method: Qualitative data was collected from 36 subjects as part of the Department of Veterans Affairs (VA) Study to Optimize the DEKA Arm through surveys, interviews, audio memos, and videotaped sessions. Three major, interrelated themes were identified using the constant comparative method: attitudes towards foot controls, psychomotor learning and physical experience of using foot controls. Results: Feedback about foot controls was generally positive for all iterations. The final version of foot controls was viewed most favorably. Conclusions: Our findings indicate that foot controls are a viable control option that can enable control of a multifunction upper limb prosthesis (the DEKA Arm).

• Implications for Rehabilitation

• Multifunction upper limb prostheses require many user control inputs to operate. Foot controls offer additional control input options for such advanced devices, yet have had minimal study.

• This study found that foot controls were a viable option for controlling multifunction upper limb prostheses. Most of the 36 subjects in this study were willing to adopt foot controls to control the multiple degrees of freedom of the DEKA Arm.

• With training and practice, all users were able to develop the psychomotor skills needed to successfully operate food controls. Some had initial difficulty, but acclimated over time.

     

Cognitive predictors of skilled performance with an advanced upper limb multifunction prosthesis: a preliminary analysis

Purpose The objectives were to 1) identify major cognitive domains involved in learning to use the DEKA Arm; 2) specify cognitive domain-specific skills associated with basic versus advanced users; and 3) examine whether baseline memory and executive function predicted learning. Method Sample included 35 persons with upper limb amputation. Subjects were administered a brief neuropsychological test battery prior to start of DEKA Arm training, as well as physical performance measures at the onset of, and following training. Multiple regression models controlling for age and including neuropsychological tests were developed to predict physical performance scores. Prosthetic performance scores were divided into quartiles and independent samples t-tests compared neuropsychological test scores of advanced scorers and basic scorers. Baseline neuropsychological test scores were used to predict change in scores on physical performance measures across time. Results Cognitive domains of attention and processing speed were statistically significantly related to proficiency of DEKA Arm use and predicted level of proficiency. Conclusions Results support use of neuropsychological tests to predict learning and use of a multifunctional prosthesis. Assessment of cognitive status at the outset of training may help set expectations for the duration and outcomes of treatment.

• Implications for Rehabilitation

• Cognitive domains of attention and processing speed were significantly related to level of proficiencyof an advanced multifunctional prosthesis (the DEKA Arm) after training.

• Results provide initial support for the use of neuropsychological tests to predict advanced learningand use of a multifunctional prosthesis in upper-limb amputees.

• Results suggest that assessment of patients’ cognitive status at the outset of upper limb prosthetictraining may, in the future, help patients, their families and therapists set expectations for theduration and intensity of training and may help set reasonable proficiency goals.

     

Feminine identity and functional benefits are key factors in women’s decision making about upper limb prostheses: a case series

Purpose: Although the DEKA Arm promises new abilities, it is unclear if women with upper limb amputation are willing to avail themselves of this new technology. The study purpose was to understand key factors and tradeoffs that shape women’s attitudes towards the DEKA Arm.

Methods: This case series includes three women with transradial amputation. Structured surveys and semi-guided interviews were administered after completion of in-laboratory training and a home trial of the DEKA Arm. A constant comparative method with a grounded theory approach was used to generate a model describing women’s decision-making related to the DEKA Arm. Quantitative data on prosthetic satisfaction was used to triangulate findings.

Results: Factors that enhanced desirability of the DEKA Arm were improved functionality, increased abilities and the availability of someone to service the prosthesis. Factors that detracted from desirability of the device were its appearance, conspicuousness, lifestyle incompatibility, weight, need for service and difficulty of use. Each woman weighted these factors within the larger context of the capabilities of and satisfaction with her personal prostheses, her self-concept and lifestyle needs. Situational demands, particularly the desire to appear feminine and professional or need to perform certain activities, also altered the valuation of these priorities.

Conclusion: Findings strongly suggest that advanced upper limb prosthetic technologies, like the DEKA Arm, will be better accepted by women if appropriately gendered in appearance and designed with women’s priorities in mind.

• Implications for Rehabilitation

• Women should be able to derive the functional benefits of advances in upper limb technology without needing to compromise their feminine identity and lifestyle preferences.

• Advanced upper limb prosthetic technologies will be better accepted by women if they are appropriately gendered.

     

3D-printed upper limb prostheses: a review

Goal: This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users.

Methods: A review was performed using Scopus, Web of Science and websites related to 3D-printing. Quantitative information on the mechanical and kinematic specifications and 3D-printing technology used was extracted from the papers and websites.

Results: The overview (58 devices) provides the general specifications, the mechanical and kinematic specifications of the devices and information regarding the 3D-printing technology used for hands. The overview shows prostheses for all different upper limb amputation levels with different types of control and a maximum material cost of $500.

Conclusion: A large range of various prostheses have been 3D-printed, of which the majority are used by children. Evidence with respect to the user acceptance, functionality and durability of the 3D-printed hands is lacking. Contrary to what is often claimed, 3D-printing is not necessarily cheap, e.g., injection moulding can be cheaper. Conversely, 3D-printing provides a promising possibility for individualization, e.g., personalized socket, colour, shape and size, without the need for adjusting the production machine.

• Implications for rehabilitation

• Upper limb deficiency is a condition in which a part of the upper limb is missing as a result of a congenital limb deficiency of as a result of an amputation.

• A prosthetic hand can restore some of the functions of a missing limb and help the user in performing activities of daily living.

• Using 3D-printing technology is one of the solutions to manufacture hand prostheses.

• This overview provides information about the general, mechanical and kinematic specifications of all the devices and it provides the information about the 3D-printing technology used to print the hands.

     

Prosthesis use in adult acquired major upper-limb amputees: patterns of wear,prosthetic skills and the actual use of prostheses in activities of daily life

Purpose: To describe patterns of prosthesis wear and perceived prosthetic usefulness in adult acquired upper-limb amputees (ULAs). To describe prosthetic skills in activities of daily life (ADL) and the actual use of prostheses in the performance of ADL tasks. To estimate the influence of prosthetic skills on actual prosthesis use and the influence of background factors on prosthetic skills and actual prosthesis use. Method: Cross-sectional study analysing population-based questionnaire data (n?=?224) and data from interviews and clinical testing in a referred/convenience sample of prosthesis-wearing ULAs (n?=?50). Effects were analysed using linear regression. Results: 80.8% wore prostheses. 90.3% reported their most worn prosthesis as useful. Prosthetic usefulness profiles varied with prosthetic type. Despite demonstrating good prosthetic skills, the amputees reported actual prosthesis use in only about half of the ADL tasks performed in everyday life. In unilateral amputees, increased actual use was associated with sufficient prosthetic training and with the use of myoelectric vs cosmetic prostheses, regardless of amputation level. Prosthetic skills did not affect actual prosthesis use. No background factors showed significant effect on prosthetic skills. Conclusions: Most major ULAs wear prostheses. Individualised prosthetic training and fitting of myoelectric rather than passive prostheses may increase actual prosthesis use in ADL.

Implications for Rehabilitation

• Arm prostheses are important functional aids for adult acquired major upper-limb amputees (ULAs).

• Despite being mainly satisfied with their prostheses, reporting their prostheses as useful and showing good prosthetic skills, prosthesis-wearing major ULAs do not use their prostheses for more than about half of the activities of daily life (ADL) tasks carried out in everyday life.

• In unilateral ULAs, individualised and targeted prosthetic training may increase optimal, active prosthesis use in ADL.

• Fitting the amputee with myoelectric rather than passive prostheses may increase prosthesis use in ADL, regardless of amputation level.

     

Training to use a commercial brain-computer interface as access technology: a case study

Purpose: This case study describes how an individual with spastic quadriplegic cerebral palsy was trained over a period of four weeks to use a commercial electroencephalography (EEG)-based brain-computer interface (BCI). Method: The participant spent three sessions exploring the system, and seven sessions playing a game focused on EEG feedback training of left and right arm motor imagery and a customised, training game paradigm was employed. Results: The participant showed improvement in the production of two distinct EEG patterns. The participant’s performance was influenced by motivation, fatigue and concentration. Six weeks post-training the participant could still control the BCI and used this to type a sentence using an augmentative and alternative communication application on a wirelessly linked device. Conclusions: The results from this case study highlight the importance of creating a dynamic, relevant and engaging training environment for BCIs.

• Implications for Rehabilitation

• Customising a training paradigm to suit the users’ interests can influence adherence to assistive technology training.

• Mood, fatigue, physical illness and motivation influence the usability of a brain-computer interface.

• Commercial brain-computer interfaces, which require little set up time, may be used as access technology for individuals with severe disabilities

     

Recovery-related anxiety and disability following upper limb injury: the importance of context

Abstract

Purpose: Anxiety following traumatic upper limb injury is common and may affect rehabilitation outcomes. Most previous research has focused on psychiatric anxiety disorders among those with severe injuries. The aims of this study were to determine the prevalence of anxiety among patients with mild to moderate traumatic upper limb injuries, to investigate the correlation between anxiety and disability, and to provide preliminary validation of the Recovery-Related Anxiety Questionnaire (RRAQ). Method: Eighty-four adults with a recent traumatic upper limb injury completed the State & Trait Anxiety Inventory (STAI), the Pain Anxiety Symptoms Scale (PASS-20), the RRAQ and the shortened Disability of the Arm, Shoulder and Hand Questionnaire (QuickDASH). Prevalence rates of anxiety were calculated and linear regression analysis was used to identify predictors of QuickDASH scores. Results: All participants reported some anxiety, with higher levels of recovery-related anxiety than general anxiety. In linear regression analysis, the four types of anxiety accounted for 29% of the variability in QuickDASH scores. The RRAQ accounted for 19% of the variability in QuickDASH scores. Conclusions: Recovery-related forms of anxiety appear to be more common and more strongly associated with disability than general anxiety symptoms for patients with mild to moderate traumatic upper limb injuries.

• Implications for Rehabilitation

• Following mild to moderate traumatic upper limb injury, anxiety about the injury and recovery is common.

• Recovery-related anxiety is more strongly associated with disability than general anxiety symptoms.

• Phrasing questions about anxiety directly associated with the recovery experience may give greater insight into the anxiety patients with mild to moderate upper limb injuries are experiencing.

• This insight may help clinicians to directly address recovery-related issues, potentially decreasing disability experienced by patients.

     

The influence of lower-limb prostheses technology on Paracanoeing time-trial performance

Within the Paracanoeing discipline, it is important to ensure that appropriate control is achieved by a paddler with a disability. However, this Paralympic Games discipline has seen very little attention to date. The aims of this study were to understand the kinematic impact to a paracanoeist when not utilizing the use of a prosthetic lower-limb. A kayaker with a uni-lateral transfemoral amputation completed several 200?m maximal efforts both with and without their prosthesis. When the prosthetic limb was removed, there were significant differences found in stroke rate, stroke speed, stroke length and overall power output. Sagittal and frontal video analysis demonstrated the residual limb movements when paddling and indicated where support would be required to improve the kayak’s control. It is recommended that those with lower-limb absence wishing to paddle a kayak competitively utilize the use of a prostheses designed for the kayaking environment that supports the residual limb at both the upper and inner thigh and the distal end.

• Implications for rehabilitation

• This paper is the first study to investigate both biomechanical and assistive technology-related issues in the new Paralympic Games sport of Paracanoeing.

• For participants possessing lower-limb absence, a prosthetic limb that is designed specifically for the kayaking environment is recommended when Paracanoeing to maximize efficient propulsion.

• Use of an ergometer and multiple 2D cameras provides practitioners the ability to optimize both the comfort and fit of a prosthetic limb.

• Use of an ergometer and multiple 2D cameras provides both athletes and practitioners the ability to optimize the points of human contact within a kayak to ensure comfort and control.

     

H-GRASP: the feasibility of an upper limb home exercise program monitored by phone for individuals post stroke

Purpose: To investigate the feasibility of a phone-monitored home exercise program for the upper limb following stroke. Methods: A pre-post double baseline repeated measures design was used. Participants completed an 8-week home exercise program that included behavioural strategies to promote greater use of the affected upper limb. Participants were monitored weekly by therapists over the phone. The following feasibility outcomes were collected: Process (e.g. recruitment rate); Resources (e.g. exercise adherence rate); Management (e.g. therapist monitoring) and Scientific (e.g. safety, effect sizes). Clinical outcomes included: The Chedoke Arm and Hand Inventory, Motor Activity Log, grip strength and the Canadian Occupational Performance Measure. Results: Eight individuals with stroke were recruited and six participants completed the exercise program. All but one of the six participants met the exercise target of 60?minutes/day, 6 days/week. Participants were stable across the baseline period. The following post-treatment effect sizes were observed: CAHAI (0.944, p?=?0.046); MALQ (0.789, p?=?0.03) grip strength (0.947, p?=?0.046); COPM (0.789, p?=?0.03). Improvements were maintained at three and six month follow ups. Conclusions: Community dwelling individuals with stroke may benefit from a phone-monitored upper limb home exercise program that includes behavioural strategies that promote transfer of exercise gains into daily upper limb use.

• Implications for Rehabilitation

• A repetitive, task-oriented home exercise program that utilizes telephone supervision may be an effective method for the treatment of the upper limb following stroke

• This program is best suited for individuals with mild to moderate level impairment and experience a sufficient level of challenge from the exercises

• An exercise program that includes behavioural strategies may promote transfer of exercise gains into greater use of the affected upper limb during daily activities

     

The impact of lower-limb prosthetic limb use in international C4 track para-cycling

Abstract

An investigation was undertaken to ascertain any impact or significance of athletes within the C4 paracycling classification between those who use a lower-limb prostheses and those who do not. A statistical evaluation of event completion time was undertaken to assess C4 cyclists when competing at the World Championships and the Paralympic Games in the 1?km track time trial. The C4 athletes who utilize a prostheses consistently outperformed non-amputees in the C4 classification from 2011 to 2016 on a competition-to-competition basis. However, when the participations were grouped as a whole together and an identified outlier athlete was removed, it was then demonstrated that there was no statistical significance between those who required the use of a lower-limb prostheses to those that did not when either evaluated on a competition-by-competition or on an amputee and non-amputee group-by-group basis (p?≥?0.05). As a result, this study proposes that those requiring the use of lower-limb prostheses are neither advantaged nor disadvantaged in the C4 classification category when competing in the 1?km time trial at this time.

• Implications for Rehabilitation

• This analysis indicates that at this time, there is no evidence to suggest that use of such technology is advantageous in this category or should be seen as controversial.

• The design of lower-limb prosthetic limb technology in cycling should continue to be developed and optimized unabated.

• This study begins to address the cited lack of peer-reviewed information regarding paracycling with limb absence available to practitioners.

     

Self-reported use of the upper limbs related to clinical tests in persons with multiple sclerosis

Abstract

Purpose: This study investigated the relationship between self-reported use of the upper limbs and clinical tests in persons with multiple sclerosis (pwMS). Methods: This cross-sectional study involved 25?pwMS with upper limb dysfunction. The Motor Activity Log (MAL) was bilaterally applied to investigate the self-reported use of both upper limbs. Clinical tests on function level were the Motricity Index (MI) and the Brunnström–Fugl–Meyer (BFM). On activity level, the Action Research Arm test (ARAt) was conducted. To identify the relationship between the self-reported use and the clinical tests, Spearman correlation coefficients were calculated. Subgroups of dominant and non-dominant arms were differentiated, and compared with the Wilcoxon Signed rank test. Results: The highest correlations were found between the MAL and function level tests: MI (r?=?0.83, p?<?0.01) and BFM (r?=?0.75, p?<?0.01). A lower correlation was found between the MAL and the ARAt (r?=?0.49, p?<?0.01). For all outcome measures, the absolute scores were higher for the dominant hand. Higher correlations were found for the non-dominant compared to the dominant hand. Conclusion: The self-reported use of the upper limbs was highly associated with measures on function level. The association with activity level was, however, less pronounced. Magnitudes of relationships were influenced by hand dominance.

• Implications for Rehabilitation

• Self-reported use of the upper limbs in persons with MS, measured by the MAL, is highly associated with muscle strength and movement control.

• The ARAt (activity level of the ICF) is less associated with self-reported use compared to outcome measures at function level.

• The ARAt seems to be less sensitive to mild arm dysfunction.

• This study indicates that it is feasible and clinically relevant to apply the MAL as a self-reported outcome measure of upper limb use in MS.

     

Validity,reliability and ease of use of the disabilities of arm,shoulder and hand questionnaire in adults following stroke

Purpose: The Disabilities of Arm, Shoulder and Hand (DASH) questionnaire is a patient reported outcome measure for evaluating upper limb function in people with musculoskeletal conditions. While the DASH has good psychometric properties when used with people with musculoskeletal conditions, it has not been tested with adults after stroke.

Methods: Data for n?=?61 adults following stroke (aged 32–93 years, 44% male) were analyzed to test validity and reliability of the DASH for use with a stroke population. Data included demographic and clinical attributes, DASH scores (baseline and four weeks later) and Patient Rated Wrist Evaluation (PRWE) measures.

Results: Internal consistency was good (Cronbach alpha 0.92, SEM 6.65). Factor analysis and Rasch modeling suggested that the questionnaire comprised three subscales: pain, impact and function. Concurrent validity between the DASH and PRWE (Spearman’s Rho r_s?=_?0.41) was moderate. The scale was perceived by clinicians to be useful, quick and simple to administer. The DASH had low four-week test-retest reliability (ICC 0.56 [95% Cl 0.05–0.79]).

Conclusions: The DASH is considered to have acceptable validity when used with adults following stroke. Test–retest reliability was low but further research is needed to establish whether this is a result of condition-related change or the stability of the measure.

• Implications for Rehabilitation

• The DASH questionnaire examines upper limb function in task performance and appears to be a useful tool, which is simple to administer in the clinical setting with adults following stroke.

• Upper limb function post stroke can be meaningfully assessed using the DASH as it has good internal consistency and moderate concurrent validity.

• Rasch analysis and factor analysis suggests that the tool appears to consist of three subscales: pain, impact and function. The total score of the DASH may be less meaningful than the totals of these subscales.

• The test–retest reliability of the DASH requires further research; over a four-week period DASH stability was poor in a group of people with moderate to severe upper limb impairment.

     

Intensive virtual reality-based training for upper limb motor function in chronic stroke: a feasibility study using a single case experimental design and fMRI

Purpose: To evaluate feasibility and neurophysiological changes after virtual reality (VR)-based training of upper limb (UL) movements. Method: Single-case A-B-A-design with two male stroke patients (P1:67?y and 50?y, 3.5 and 3?y after onset) with UL motor impairments, 45-min therapy sessions 5×/week over 4 weeks. Patients facing screen, used bimanual data gloves to control virtual arms. Three applications trained bimanual reaching, grasping, hand opening. Assessments during 2-week baseline, weekly during intervention, at 3-month follow-up (FU): Goal Attainment Scale (GAS), Chedoke Arm and Hand Activity Inventory (CAHAI), Chedoke-McMaster Stroke Assessment (CMSA), Extended Barthel Index (EBI), Motor Activity Log (MAL). Functional magnetic resonance imaging scans (FMRI) before, immediately after treatment and at FU. Results: P1 executed 5478 grasps (paretic arm). Improvements in CAHAI (+4) were maintained at FU. GAS changed to +1 post-test and +2 at FU. P2 executed 9835 grasps (paretic arm). CAHAI improvements (+13) were maintained at FU. GAS scores changed to ?1 post-test and +1 at FU. MAL scores changed from 3.7 at pre-test to 5.5 post-test and 3.3 at FU. Conclusion: The VR-based intervention was feasible, safe, and intense. Adjustable application settings maintained training challenge and patient motivation. ADL-relevant UL functional improvements persisted at FU and were related to changed cortical activation patterns.

• Implications for Rehabilitation

• YouGrabber trains uni- and bimanual upper motor function. Its application is feasible, safe, and intense.

• The control of the virtual arms can be done in three main ways: (a) normal (b) virtual mirror therapy, or (c) virtual following. The mirroring feature provides an illusion of affected limb movements during the period when the affected upper limb (UL) is resting.

• The YouGrabber training led to ADL-relevant UL functional improvements that were still assessable 12 weeks after intervention finalization and were related to changed cortical activation patterns.

     

Non-invasive brain stimulation for the lower limb after stroke: what do we know so far and what should we be doing next?

Background: Non-invasive brain stimulation (NIBS) is promising as an adjuvant to rehabilitation of motor function after stroke. Despite numerous studies and reviews for the upper limb, NIBS targeting the lower limb and gait recovery after stroke is a newly emerging field of research. Purpose: To summarize findings from studies using NIBS to target the lower limb in stroke survivors. Methods: This narrative review describes studies of repetitive transcranial magnetic stimulation, paired associative stimulation and transcranial direct current stimulation with survivors of stroke. Results: NIBS appears capable of inducing changes in cortical excitability and lower limb function, but stimulation parameters and study designs vary considerably making it difficult to determine effectiveness. Conclusions: Future research should systematically assess differences in response with different stimulation parameters, test measures for determining who would be most likely to benefit and assess effectiveness with large samples before NIBS can be considered for use in clinical practice.

• Implications for Rehabilitation

• Stroke is a leading cause of disability, often resulting in dependency in activities of daily living and reduced quality of life.

• Non-invasive brain stimulation has received considerable interest as a potential adjuvant to rehabilitation after stroke and this review summarizes studies targeting the lower limb and gait recovery.

• Non-invasive brain stimulation can be used to modulate excitability of lower limb muscle representations and can lead to improvements in motor performance in stroke survivors.

• Non-invasive brain stimulation for gait recovery needs further investigation before translation to clinical practice is possible.

     

Abandonment of assistive products: assessing abandonment levels and factors that impact on it

Purpose: To investigate the levels and factors that influence the abandonment of assistive products by users of a local reference rehabilitation center.

Methods: This observational study involved users who received services and assistive products provided by our center of rehabilitation. Users were identified using the records of the center and their responses about the abandonment were collected through face-to-face interviews.

Results: The abandonment level of assistive products was 19.38%. 83.5% of the users use at least one of the assistive products they have received. Rigid and folding frame wheelchairs, with and without postural support devices, as well as shower wheelchairs, presented the lowest abandonment levels, followed by canes and lower limb orthoses. Upper limb orthoses, Knee Ankle Foot Orthosis(KAFO), walkers, crutches and lower and upper limb prostheses all presented higher abandonment levels.

Conclusion: The simultaneous use of mutiple assistive products, users perception on the importance of using them, and completing the rehabilitation treatment were found to impact on the short and long-term use of products. The study offers inputs to decision making and planning for assistive technology provision in developing countries with regard to expected demand and service delivery.

• Implications for Rehabilitation

• Data about the abandonment of assistive products in Sao Paulo, Brazil, could assist informing decision making on provision and servicing of these products in similar settings.

• The strong correlation found between abandonment levels and the simultaneous use of multiple devices should be taken into account by health professionals when prescribing assistive products and providing guidance to users.

• The need for follow up on the use of assistive products after discharge from rehabilitation treatment becomes strikingly clear, as data show that completing treatment is significantly relevant when evaluating abandonment levels.

• As assistive products users’ perception about the importance of using these devices is shown to be significant in explaining abandonment, it is mandatory that health and rehabilitation professionals take it into account when providing guidance and training users.