The effect of visual feedback on the error
augmentation protocol applied to an upper
extremity task
Bacherlor thesis
Name and student number:
M. Boonstra (500739153) M. Keesman (500736621) Y.Z.J. Stoppkotte (500724714)
Bachelor Occupational Therapy, Amsterdam University of Applied Sciences Montréal, Canada. 3th June 2019
8922 words
First examinator: H. Tonneijck
In cooperation with: Institut de readaption Gingras Lindsay de Montréal Supervisor: J. Higgins
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The copyright is from the University of Applied Sciences of Amsterdam. The supervisor has free access to the thesis for own use. The supervisor determinants in the evaluation if he or she gives permission to publish the thesis in a public database of the University of Applied Sciences of Amsterdam.
Preface
This thesis is written as a part of the bachelor graduation program of the University of Applied Sciences in Amsterdam in the department occupational therapy. It is written by three
occupational students, the thesis has been written in Montréal, Canada.
In this preface we would firstly like to thank our supervisor Johanne Higgins for the guidance, she gave us during our thesis. We would also like to thank Johanne Higgins and Sylvie Nadeau (researchers of the rehabilitation centre) for giving us the opportunity to be part of their research in Montréal, Canada. We also want to thank our coach Hetty Tonneijck for her feedback and the Skype meetings in which we could discuss our project, her feedback made it possible for us to look at our thesis in a different way.
During the experiment there were also people who made it possible for us to collect data, we would like to thank the engineer Philippe Gourdou for making it possible for us to collect the data. Since it was our first time analyzing data, we needed help to be able to understand all the data and how to draw the right conclusions. Aurélien Jacquet and Amine Guediri took the time and patience to explain the data to us, so we would like to thank them as well.
The book ‘Praktijkgericht onderzoek’ (Wouters, Zaalen, & Bruijning, 2015) was used for the layout and content of this thesis, because it gave us as first-time researcher trainees support to make sure we put all the relevant subjects in the thesis. The book is written by three paramedic lecturers, therefore this book is a good guideline, since Occupational Therapy is also part of paramedical care.
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Index
PREFACE ... 30. ABSTRACT ... 5
1.
INTRODUCTION ... 6
2. OBJECTIVE ... 11
2.1 MAIN OBJECTIVE: ... 12
3. METHODS ... 13
3.1 RESEARCH DESIGN ... 13
3.1.1 RESEARCH DESIGN LITERATURE REVIEWS ... 13
3.1.2 RESEARCH DESIGN CROSS-SECTIONAL STUDY ... 13
3.2 CHARACTERISTICS OF THE PARTICIPANTS OF THE EXPERIMENT ... 14
3.3 MEASUREMENTS OF THE EXPERIMENT ... 14
3.4 DESCRIPTION OF THE APPARATUS ... 15
3.5 DATA COLLECTION OF THE EXPERIMENT ... 16
3.6 DATA ANALYSIS OF THE EXPERIMENT ... 17
3.7 ETHICS OF THE EXPERIMENT ... 18
4. RESULTS ... 19
4.1 LITERATURE REVIEWS ... 19
4.1.1 WHAT IS THE EFFECT OF MIRROR THERAPY ON MOTOR LEARNING IN THE UPPER EXTREMITIES OF PERSONS WITH STROKE? ... 19
4.1.2 WHAT IS THE EFFECT OF VISUAL FEEDBACK ON THE FUNCTION RECOVERY OF THE ARM/HAND FUNCTION IN REHABILITATION FOR ADULTS WITH A STROKE? ... 19
4.1.3 WHAT IS THE ADDED VALUE OF ERROR IN MOTOR LEARNING? ... 20
4.2 RESULTS EXPERIMENT ... 20
4.3 INTERPRETATION OF EXPERIMENT ... 22
4.4 SYNTHESIS ... 23
5. DISCUSSION ... 24
5.1 IMPLICATIONS FOR FURTHER RESEARCH ... 25
5.2 LIMITATIONS ... 26
5.3 RECOMMENDATIONS ... 26
6. CONCLUSION ... 27
7. REFERENCES ... 28
0. Abstract
Introduction: Worldwide, cerebrovascular accidents (CVA) or stroke are the second leading
cause of death and the third leading cause of disability (Johnson, Onuma, Owolabi, & Sachdev, 2016). The people who survive will most likely enter rehabilitation to improve or learn how to live with the consequences of a stroke. These can vary from physical disabilities tot cognitive
disabilities. The focus in rehabilitation relies mostly on compensating than getting function back, due to time. This is why in the lab of Institut de readaptation Gingras Lindsay de Montreal (IRGLM) an apparatus has been developed which works according to the error-augmentation theory. The current protocol written for the apparatus is using visual feedback. The aim of this research will be determining the effect of visual feedback (VF) on the current protocol to make suggestions for improving the intervention of the apparatus, since the current protocol is only using visual feedback and we would like to know the influence on the performance of the participants when compared with VF and without VF. Method: A cross-sectional study design was used for this research in combination with a literature review to substantiate the outcome of the study. For the cross-sectional study, 10 healthy individuals participated in an experiment that is based on an error augmentation (EA) protocol. In the experiment participants were seated in an apparatus while holding handles. All participants were making pushing movements with their arms. The objective of the study the focus were to determine the effects of VF on the post effects of the error augmentation (EA) protocol. To look at this effect the participants will perform the experiment in two conditions; a condition with and a condition without VF. Results: The results from the literature reviews showed that VF has a positive influence on arm/hand function recovery in people with stroke. It also showed that EA has a positive influence on motor learning: the greater the error, the easier it is to register the error for the affected brain. The results from the cross-sectional study showed that participants were more consistent in strength in the push movement when they did not receive VF.
Discussion:The limitations of the research were that the sample size group was small (N=10),
all participants were employees of the rehabilitation centre and were aware of the hypothesis being tested. However they were diverse in age, size and weight. Data collected through the research was randomized. Further research will be needed to establish the effects of visual feedback on the long-term in stroke patients.
Conclusion: This thesis showed that the participants were more consistent during their push
movement without visual feedback in the cross-sectional study. This is in contradiction with findings in literature which indicate that VF has a positive influence on interventions where arm/hand training is taking place.
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1. Introduction
Epidemiology of stroke
Every year around 43000 people sustain a stroke in the Netherlands. That’s approximately 117 per day (De Nederlandse Hartstichting, n.d.). A stroke is a cardiovascular disease and is a major cause of death in the Netherlands. In 2017, 9180 people died as a result of a stroke, of which 5421 were female and 3759 were men. Stroke is the second most common cause of death in women and third in men (National Institute for Public Health and Environment, n.d.). The prevalence of stroke has risen in recent years as a result of the aging population, whereas the incidence has remained stable. The prevalence in women is 27.7 per 1000 women and 28.1 per 1000 men (Nederlandse Hartstichting, n.d.). The incidence of stroke increases rapidly with age. The incidence per age category is higher for men than for women (Dutch General
Practitioners Society, n.d.). Figures in Canada are also high. One of the reasons is that Canada also has to deal with an aging population (Canada Postennet, 2017).
Causes of stroke
The medical term for stroke is Cerebrovascular Accident (CVA) and is used as a collective term for various problems regarding the blood supply to the brain (De Nederlandse Hartstichting, n.d.). Included in this general term are: cerebral infarction, Transient Ischemic Attack (TIA) and brain haemorrhage. In a cerebral infarction and a TIA there is a blood clot that blocks a blood vessel in the brain. An artery or small blood vessel that ensures that oxygen-rich blood comes into all parts of the brain can become constricted or blocked. This is often the result of arterial calcification: fatty substances (cholesterol) and blood clots attach themselves to a damaged part of the blood vessel wall. This clot can accumulate so far that the artery becomes silted up. A piece of a blood clot can also come loose and block a smaller artery further into the brain. The difference between a stroke and a TIA is that the consequences (see next paragraph) of a TIA disappear within a few hours, whereas with a cerebral infarction, consequences remain for a longer period of time and sequelae may be permanent (Hersenletsel-uitleg, n.d.).
A cerebral haemorrhage, a serious form of stroke, occurs when a blood vessel in the brain bursts. A blood vessel tears and blood flows in and around the brain. The blood pushes away part of the brain tissue, causing it to become damaged (Hersenstichting, n.d.). Bleeding in the brain can have various causes, such as high blood pressure, vascular abnormalities and brain tumour, but also as result of pregnancy complications or accident (Hersenletsel-uitleg, n.d.).
Consequences of stroke
Apart from the fact that a stroke is a major cause of death, a stroke usually has far-reaching consequences for those who survive due to the damage to the brain tissue that accompanies it. A stroke can happen anywhere in the brain. In all cases of stroke (hemorrhagic, ischemic or TIA) a part of the brain is deprived of oxygen. The longer the brain is deprived of oxygen, the more damaged it will get. In most cases the brain cells in the brain area that is connected to the vessel that bursts (hemorrhagic) or to the vessel that has a blood clot will die due to the lack of oxygen. When brain cells die, abilities controlled by that area of the brain such as memory, speech and muscle control are lost (National Stroke Association, 2018).
In each phase (acute, sub-acute and chronic) after a stroke, persons may experience problems with resuming their lives. This is because stroke often causes physical consequences, such as paralysis, fatigue, problems with vision, coordination and balance, but also incontinence. In addition to the physical consequences, stroke has also often consequences on a person’s cognitive ability. These are often invisible and difficult problems. After stroke, problems with
speech often occur. Speech disorders (dysarthria) cause difficulty with pronouncing words. If the language area is damaged by stroke, speaking or understanding the language is more difficult. This is also called aphasia (De Nederlandse Hartstichting, n.d.).
Motor failure is a common symptom of stroke. Weakness or paralysis is the primary symptom after stroke, this due to the lack of signal transmission between the motor area of the brain and the muscle. Also, spasticity and sensory loss are common symptoms of stroke (Raghavan, 2015). Figures show that after half a year about 50% of patients still have motor failure in at least one limb (Nederlands Huisartsen Genootschap, n.d.).
Common manifestations of motor impairment include muscle weakness or contracture, changes in muscle tone, joint laxity, and impaired motor control. These impairments induce disabilities in common activities such as reaching, picking up objects, walking and holding onto objects. Motor function deficits due to stroke affect the patients' mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life (Hatem et al., 2016).
Stroke management Acute care
In the acute and subacute phases, care is mainly focused on medical treatment, prevention of complications and assessment of the consequences of stroke for daily life. Some people
continue the treatment process in the rehabilitation phase in a clinical or outpatient rehabilitation trajectory. This care is provided by the hospital (outpatient), rehabilitation centre (clinical and outpatient rehabilitation), institutions for elderly care (clinical geriatric rehabilitation, day
treatment, home treatment) and first-line practises (Steultjens, Cup, Zajec, & van Hees, 2013). During treatment process, a multidisciplinary team is often involved, consisting of a rehabilitation physician, occupational therapists, physiotherapists/exercise therapists, speech therapists and psychologists.
Rehabilitation
Recovery from stroke is a complex process that likely occurs through a combination of spontaneous and learning mediated processes (Colombo, Sterpia, Mazzone, Delconte, & Pisano, 2013). Physical guidance is often given in rehabilitation settings by a therapist such as an occupational therapist. The rehabilitation program for people after stroke may consist of several interventions. These interventions are training/therapies and are described in the stroke guidelines (Steultjens et al., 2013), which are evidence-based.
Occupational Therapy
Occupational therapists practice with people the activities of daily life that they consider
important. This practice is aimed both at restoring motor, cognitive and psychosocial skills and at being able to perform (adapted) important activities that contribute to participation (Steultjens et al., 2013). The focus of occupational therapy is to help individuals achieve health, well-being, and participation in life through engagement in occupations (i.e., activities). Occupational therapists understand the importance of emotional well-being, social connections, and healthy life habits for individuals post-stroke. In addition to ongoing physical rehabilitation, they engage stroke survivors and family members to take charge of their lives, create human connections, and lead healthy lifestyles. This may include developing coping strategies to deal with loss, individualized ways to promote psychosocial health, education to minimize potential for a second stroke, promotion of increased exercise and healthy eating, and strategies to overcome barriers to sexual intimacy (American Occupational Therapy Association [AOTA], 2014). The
8 occupational therapist also participates in the motor training by doing for example task-oriented training, constraint-induced movement therapy, and mirror therapy with stroke patients since in these training motor learning occurs.
Rehabilitation of the upper extremity after stroke
Motor failure in the upper extremities is one of the most common symptoms after a stroke, plays a crucial role in the independent performance of daily activities and is also one of the main causes of disability in adults (hersenletsel-uitleg, n.d.).
The following interventions are described in the stroke guidelines to improve the recovery of arm/hand function for people after a stroke:
- Task-Oriented Training; ‘’Task-oriented training involves practising real-life tasks (such as answering a telephone), with the intention of acquiring or re-acquiring a skill (defined by consistency, flexibility and efficiency). The tasks should be challenging and
progressively adapted and should involve active participation’’ (Herbert & Teasell, 2015). - Constraint Induced Movement Therapy; ‘’Traditional constraint-induced movement
therapy (CIMT) involves restraint of the unaffected arm for at least 90% of waking hours, and at least six hours a day of intense upper extremity (UE) training of the affected arm every day for two weeks. This form of therapy may be effective for a select group of patients who demonstrate some degree of active wrist and arm movement and have minimal sensory or cognitive deficits’’ (Herbert & Teasell, 2015).
- Other interventions are: Mental Practice, Virtual Reality and Bilateral/Unilateral Arm Training (Herbert & Teasell, 2015).
The use of visual feedback and robotics for rehabilitation Mirror therapy
Mirror therapy; ‘’is a technique that uses visual feedback about motor performance as a means to enhance upper-limb function following stroke’’ (Herbert & Teasell, 2015). A more in-depth research through a literature review on mirror therapy will be presented to provide a better understanding of the effect of visual feedback within rehabilitation and treatment and for substantiation required for this thesis. Mirror therapy incorporates the visual feedback aspect. The person observes their non-paretic arm performing movements through a mirror while their paretic arm is hidden. This “tricks the brain” to think the paretic arm is moving to improve function in the paretic arm (Herbert & Teasell, 2015). This is visual feedback given by using the own body of a patient, instead of a game (which is commonly used in virtual reality). This is another form of visual feedback than used in the present research but may be useful to see what the effects of mirror therapy are on motor learning/regaining function in patients with stroke. The conclusion of this literature review is described in results.
Virtual Reality
In literature there have also been studies on the use of visual feedback through Virtual Reality (VR). VR is the use of computer technology to create a simulated environment.Because VR is stated in the Canadian guidelines as a rehabilitation method to regain function in the arm/hand, a literature review has been done to get a more in-depth vision of this method. The conclusion of this literature review is described in results.
Robotics
More recently, robotic devices have been developed to provide physical guidance in
rehabilitation settings. Robotics are devices that can move and react to sensory input. Use of robotics has much potential in rehabilitation because of their ease of use, reliable measurement of performance and capability to deliver a high intensity and dosage of therapy (Domingo & Ferris, 2010). Recently, there has been a growing trend using interactive technology in addition to traditional rehabilitation methods for enhancing motor recovery. One technique that includes a robotic interface is error augmentation (EA), which utilizes erroneous feedback to enhance motor recovery after neurological damage (EA will be further explained in the thesis). Since the research in Montréal is using the EA method, it was needed to learn and understand more about this method. Therefore, this topic has been explored further through a literature review. The conclusion of this literature review is also described in results.
Research in a Montréal Laboratory
In Montréal an occupational therapist and a physical therapist in a rehabilitation centre found that there should be more focus on arm/hand function training to improve the overall recovery of the patients with stroke. To accomplish this, they developed an apparatus, analogous to a robotic device and that is based on error augmentation to regain function.
The upper extremity EA protocol
The intervention used with the apparatus is based on the error augmentation (EA) method described above. Error augmentation has been used for rehabilitation of the lower extremity after stroke on a split-belt treadmill. The task consisted of walking on a treadmill with belts that go at different speeds. The belts moved either at a slow or fast speed in the first 6 minutes. After this period, one treadmill belt is set at the slow speed while the other is set at the fast speed for 15 minutes (EA). After this 15-minute period a post-adaption period is observed when both belts are returned to the same speed. The following was concluded in the study: ‘’during split-belt treadmill locomotion, subjects with cerebral damage were able to rapidly change their walking pattern to accommodate different speed-belt relationships. This occurred regardless of whether the paretic or non-paretic leg walked on the fast belt during the adaptation period’’. EA can be used for rehabilitation as people post-stroke experience uneven strides. Regardless of the severity of sensorimotor deficits, people with cerebral damage following stroke retain the ability to make motor adaptations (Reisman et al., 2007).
The intervention in the present study consists of a session in which the participant makes pushing movements on the apparatus. In the session the participant holds a handle in each hand. The session is divided in different parts where the force required to push on the handles changes. The duration of the session is a total of 30 minutes maximum. Table 1 presents how the session is designed.
10 EA on the apparatus consist of the fact that more force is required on the right side in
comparison to the left side. The participant is asked to recognize the error and correct the movement to get a symmetrical push movement. The force exerted by the participant is displayed on a screen. The goal is to get the red stripes in the green boxes that are displayed on the screen. The red stripes correspond to the force exerted and the green boxes are the targets that represent 15% or 30% of the maximum force. The green boxes are static and the target where the participant needs to get the red stripes in. This can be accomplished by making a symmetrical push movement. Through the visual feedback given on the screen the participant will know how to adjust their force.
Thesis research
When the thesis group itself performed the movements on the apparatus they made an
interesting observation: two persons of the group were only looking at the screen for the visual feedback and the other person was looking at the screen for the feedback, but also at her hands. As a result of this observation the thesis group came up with the following question: ‘’What is the effect of visual feedback on the error augmentation protocol?” According to the study of Pellegrino et al. (2017) VF has an effect on improving the duration, smoothness, and movement extent in comparison with a rehabilitation program without visual feedback that did not have these benefits (Pellegrino et al., 2017). So a hypothesis could be that visual feedback has a positive effect on performing a task in the apparatus. Previous research that investigated EA was mostly focused on the effect of EA on brain activation and motor-learning (Marchal-Crespo, Michels, Jaeger, López-Olóriz, & Riener, 2017) and the effect of EA versus ER (error reduction) on the gait (Kao, Srivastava, Agrawal, & Scholz, 2013; Kao, Srivastava, Higginson, Agrawal, & Scholz, 2015). Sharp, Huang and Patton (2011) investigated the effect of visual EA by exposing their subjects to enlarged visual errors, where subjects practiced a sensorimotor reversal task, similar to laparoscopic surgery to see if this would enhance motor learning (Sharp et al., 2011). However, none of these researches looked at the effect of EA in the arm/hand function when there was a condition with visual feedback and a condition without visual
feedback to compare the effect of visual feedback on EA and motor learning. So, this is why we wanted to look at the effect of visual feedback on the error augmentation protocol in healthy participants.
2. Objective
As a result of aging, cardiovascular diseases, including stroke, are a major cause of death in Canada, just as in the Netherlands. Besides being a major cause of death, it causes an
increase in chronic diseases and the demand for care increases. Many people still have motor failure in one of their extremities after six months. Motor failure of upper extremities is one of the most common symptoms after stroke and plays a crucial role in the performance of daily
activities and thus corresponds to the main causes of disability in adults (hersenletsel-uitleg, n.d).
In current rehabilitation guidelines different methods are described to improve recovery of arm/hand function. However, there is still a lot to gain for recovery in the area of function recovery, because most of the training is aimed at compensation and learning to deal with the limitations instead of recovery and improvement in use of the arm and hand which is currently being done through task-oriented training, CIMT etc. (Almhdawi, Mathiowetz, White, & delMas, 2016). The different methods are based on error reduction (ER). In literature was found that another method called error augmentation (EA) achieved more results on function level than the ER method on which current interventions are based (Liu, Li, & Lamontagne,2018). With this knowledge, a device was developed in the lab in Montréal that is based on EA.
In the research in Montréal a research protocol was developed to measure the effect of the intervention with the apparatus on different biomedical surfaces of arm/hand function. The current research protocol does not describe the effect visual feedback. So, the question rose of what the effect is of visual feedback on the error-augmentation protocol.
Occupational therapy is targeting occupation in the daily living. One of the fundamental beliefs of occupational therapy is that the life of a human revolves around being through daily activities. This is just as important for health and well-being as drinking and eating (Hartingsveldt &
Kinebanian, 2010). The intervention with the apparatus measures the effect in function of upper extremities. Because of the influence of daily activities on health and well-being it is of
importance for the occupational therapist to look at the effect of the intervention of the research in Montréal on daily activities. Occupational therapists are involved in training and retraining motor skills and motor tasks. The role of the therapist is to intervene in the learning process to assist patients in achieving independence in performance of daily living skills. Although
occupational therapists teach motor skills, most therapists are not trained as extensively in skill acquisition strategies as physical therapists. Dutch occupational therapy textbooks devote little space to motor learning. Some rehabilitation disciplines have already begun to apply motor learning principles to the functional retraining of patients with neurological impairments. These principles may offer new ideas on how to improve performance. The thesis focuses on variables that affect motor learning, such as types of visual feedback and with regard to occupational therapy, facilitation of motor skills (Poole, 1991).
To answer the main question of this thesis: “what is the effect of visual feedback on the post effects generated by an error augmentation protocol during an upper extremity task?”, the main objective is divided in four sub objectives.
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2.1 Main objective:
Determine the effect of visual feedback on an error augmentation protocol during an upper extremity task in healthy participants.
To be able to determine the main objective there were made four sub objectives (1: practice research/experiment, 2,3 & 4: literature review):
1. The effect of visual feedback on the post effects produced by an error augmentation protocol on an upper extremity task in healthy participants.
2. The effect of visual feedback on the recovery of the upper extremity function in rehabilitation of adults after stroke.
3. The added value of error augmentation in motor learning.
4. The effect of mirror therapy on motor learning of the upper extremities in persons with stroke.
3. Methods
3.1 Research design
To answer the main objective of this thesis: “what is the effect of visual feedback on the post
effects generated by an error augmentation protocol during an upper extremity task?”, three sub
objectives (2,3 & 4) were put forth and answered through literature reviews to get an understanding about the topic of the main objective and to substantiate the thesis. The sub objective: determining the effect of visual feedback on the post effects produced by an error
augmentation protocol on an upper extremity task in healthy participants, is also needed to
answer the main objective. This was done through a cross sectional study. Therefore, two different research designs were used.
3.1.1 Research design literature reviews
To meet sub objective two, three and four: ”Determine the effect of visual feedback on the
recovery of the arm/hand function in rehabilitation of adults after stroke.”, “What is the added value of error augmentation in motor learning?” and “What is the effect of mirror therapy on motor learning in the upper extremities of persons with stroke?”, three literature reviews were
performed. Each member of the thesis group researched one question in different databases according to the method required by the University of Applied Sciences in Amsterdam. To make a selection of eight to ten articles peer review was used within the group to determine which articles were best for the literature study. The results were summarized and used as
substantiation for the thesis.
3.1.2 Research design cross-sectional study
To meet the main objective: “Determine the effect of visual feedback on an error augmentation
protocol during an upper extremity task in healthy participants” and the first sub objective: “Determine the effect of visual feedback on the post effects produced by an error augmentation protocol on an upper extremity task in healthy participants”, a cross-sectional study and a
literature review to substantiate the outcome of the cross-sectional study were performed. A cross-sectional study was chosen because it allows different variables. Since different variables have to be compared within the study the cross-sectional design suits the best. The design allows to measure data over a short period of time, instead of a longitudinal study. Since this thesis will be focusing on short-term effects, the cross-sectional fits best. Because the data was collected at just one moment in the experiment, recruited participants were less likely to drop out or quit, which is also a characteristic of a cross-sectional study (Cherry, 2019). The following variables will be examined: the forward force of the push movement of the right and the left hand. The purpose of the cross-sectional study is to determine variation in force of the left and the right hand and with and without visual feedback. In the thesis the cross-sectional study will be referred to as the experiment.
In the experiment the participants were seated in the apparatus while holding the handles (see figure 1). The participants were instructed to make a symmetrical push movement forward. The push movement was made against different forces, this will be further explained in the
14 force plates in the handles of the apparatus). To meet the objective of this study, participants performed the experiment in two conditions. Condition 1 with visual feedback (VF) on a computer screen and condition 2 without visual feedback (WF).
3.2 Characteristics of the participants of the experiment
Healthy subjects participated in the experiment for practical reasons, since the apparatus is still in an early stage and researchers normative data in order to make comparisons with stroke participants at a later stage. The participants were recruited at IRGLM. Ten healthy participants (mean age 31,8 years) with no history of neurological disease participated after providing informed written consent. Seven females and three males participated. All subjects were right handed. Demographic information of the participants is summarized in Tables 2.1 and 2.2.
Tabel 2.1: Participants characteristics
3.3 Measurements of the experiment
Data was collected with force plates underneath the feet, seat and in handles of the apparatus. The force plates measure a three-dimensional force (frontal, transversal and longitudinal). To start the experiment the apparatus needs to be adjusted for each participant. For more detailed information see appendix 1.
Table 2.2: Participants characteristics
3.4 Description of the apparatus
The apparatus used in the experiment consists of an instrumented seat and two handles installed on two rails that can be adjusted at the right height and angles for the participant. The handles are placed on rails, so they are able to move from proximal to distal position in a linear fashion that is analogous to a reaching movement performed with the arms. The apparatus is positioned in front of a computer screen which displays visual feedback. When the participant is asked to perform pushing movements on the handles, the visual feedback provided consists of two static green blocks (one on the right and one on the left) and two horizontal red stripes (one on the right and one on the left) which represent the activity of the push movement of the participant. The red stripes will move as soon as the participants holds the handles and will move more as the participants start to make the push movement. The apparatus only requires the participant to push, not to pull as the handles are moved back to the proximal position by the motor. When the maximal proximal position is reached (which will be determined when the apparatus is being set for the participant), the handles will pull back automatically (see figure 1).
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Figure 1: The apparatus
3.5 Data collection of the experiment
Data was collected on the forward force of the push movement in the handles used by the participant. The experiment was divided in different components and took approximately 30 minutes. The participants got the opportunity to take breaks in between the components. When the experiment starts the participant is instructed to push for 1 minute to become familiar with the apparatus and the visual feedback. After this the participant has a working time of 1 minute to push and achieve the given goal set at 15% of the maximum strength without visual feedback. There is another minute of working time with the same instructions and goal at 15% of the maximum strength of the participant but this time with visual feedback. When these two phases are done, a 6 minute (error augmentation) working time where the maximum strength of the participant is alternated between 15% and 30% takes place. In the experiment, participants push at 15% of their maximum strength on the left hand in all minutes versus 15% of the
maximum strength in the first blocks and 30% in the error augmentation minutes (6 minutes) on the right hand (see table 3). After 6 minutes there is a working time of 3 minutes at 15% of the maximum strength to test the effect of the 6 minutes. In the last 3 minutes visual feedback was randomized: condition 1 was with visual feedback on a computer screen and condition 2 was without visual feedback.
30% is set for the right hand, this means that the error augmentation (EA) is put on the
dominant hand (all the participants were right handed). There has been chosen to put the EA on the dominant hand because of Cross Education (CE), which occurs after unilateral training whereby performance of the untrained contralateral limb is enhanced. In the study of
Andrushko, Lanovaz, Björkman, Kontulainen and Farthing (2017), a few studies were named that showed that CE can preserve or “spare” strength and size of an opposite immobilized limb. This means that training the non-immobilized limb has a positive effect on muscle strength and size of the immobilized limb (Andrushko, Lanovaz, Björkman, Kontulainen, & Farthing, 2017). Andrushko et al. (2017) also state the following in their article: ‘’The concept of using CE for its sparing effects during rehabilitation from injury has the potential to reduce the total time of recovery, particularly if therapy is started before atrophy and strength deprivation begin to occur’’ (Andrushko et al., 2017). This vision and promising effect of CE is in line with the issue occurring in current health-care due to the growing population who become impaired by stroke.
Table 3: components of the experiment
*The only differences between the two conditions was in the last component where the post effects were measured.
3.6 Data analysis of the experiment
For the data analysis Excel files were put together by the engineer of the research lab. The data was from all the participants, no one dropped out or quit. As mentioned earlier, data collected from the force plates beneath the feet, seat and in the handles of the apparatus. To answer the question of this thesis data of the force plates in the handles was used. Data from the force plates indicated the amount of strength given by the participants. This could be used to
investigate how much power the participants provided during the entire cycle and how it might fluctuate. A cycle is the forward push movement, from proximal to maximal distal position of the arm which was made by pushing the handles over the rails. The proximal and distal positions were set per participant in the beginning of the experiment. By looking at this data it can be seen how the participants maintained their strength during the cycle. By comparing condition 1 with visual feedback and condition 2 without visual feedback an answer could be given to what effect visual feedback had on the post effects after error augmentation.
The experiment was divided into different components (see figure 2), in the excel files these components were linked to eight blocks. Each block in excel stands for a certain number of minutes during the experiment. This way it was possible to specifically look at the data for each minute. It was also possible to compare different minutes. For the analysis of the data in this experiment the term blocks is being used to refer to the different minutes in components.
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Figure 2: Components and blocks of the experiment
*VF: Visual Feedback, WF: Without Visual Feedback
Data from blocks 7 and 8 were used for analysis. These blocks showed the post effects after the error augmentation (EA). In condition 1, block 3 was used as baseline, for condition 2, block 2 was used. The baseline is used for comparison of the effect of visual feedback in the post effects after error augmentation. The following comparisons were made:
Forward force left hand:
- Condition 1: With visual feedback in the post effects (block 3-7-8).
- Condition 2: Without visual feedback in the post effects (block 2-7-8).
Forward force right hand:
- Condition 1: With visual feedback in the post effects (block 3-7-8).
- Condition 2: Without visual feedback in the post effects (block 2-7-8).
During analysis the left hand in condition 1 was compared to the left hand in condition 2 and the right hand of condition 1 was compared to the right hand in condition 2. The comparison
between both the left and the right hand in the two conditions were also of interest because of the error augmentation period that was given before block 7 and 8. During this period of EA the right hand was exposed to 30% of the maximal strength while the left hand was the whole experiment exposed to 15% of the maximal strength. The expectations were that mainly in the right hand the biggest differences would occur because of exposure to 30% of the maximal strength when the two conditions were compared. The analysis will be displayed in graphs showing the different blocks. The representation of the graph is explained later.
3.7 Ethics of the experiment
All necessary steps to ensure the confidentiality and respect of the participant’s privacy were taken. The collected and analyzed data were coded by the members of the team and were locked with a password to protect the participants privacy. Participants were individually informed about the purpose and procedures of the study and needed to sign the consent form before any procedure. The participants in this experiment also participated in the main research in Montréal, therefore their consent forms are signed and will not be included in this thesis in the appendix because privacy regulations. In addition, the safety of the training was monitored and ensured during each session, any manifestation of pain or discomfort of the participant caused the immediate cessation of training. The time needed to recover was determined by the
4. Results
In this chapter the results of the three literature reviews will be described as well as the results of the experiment. Meaning for the practice will be described in the discussion.
4.1 Literature reviews
4.1.1 What is the effect of mirror therapy on motor learning in the upper extremities of persons with stroke?
The conclusion of the literature review was that the effect of mirror therapy on the motor function of the upper extremities results in an improvement in function of the upper affected extremity in many cases. In a number of cases this effect manifests itself in being able to perform daily activities better, improving coordination, and being able to perform meaningful activities better (Bae et al., 2015; Park et al., 2015; Arya & Pandian, 2013; Bondoc et al., 2018; Kim et al, 2016; Zeng et al., 2018). The outcomes described above where conclusions of articles who had a sample group of chronic stroke participants. Seven articles where Randomized Controlled Trials or Pilot Randomized Controlled Trials. One article was a systematic literature review. The designs implicate high levels of evidence and can therefore be seen as reliable sources. However, the mirror therapy was different between the articles and the articles used the mirror therapy in different ways and some for different goals. Therefore, the findings that are used are used in a broad sense. The outcomes of this study are relevant for the main question because of the effect of visual feedback on therapy in rehabilitation and how this influences recovery. See appendix 2 for more detailed findings.
4.1.2 What is the effect of visual feedback on the function recovery of the arm/hand function in rehabilitation for adults with a stroke?
A randomized control trial by Jo, Yu and Jung (2012) investigated whether virtual reality (VR) had an effect on the function of the upper extremities and visual perception. The conclusion of this research was that through the use of VR and the application of visual and auditory feedback the recovery of motor function is promoted (Jo et al., 2012). This was also described in the conclusion of the literature study by Parker et al. (2011), which also looked at the effect of visual and auditory feedback in computer technology in rehabilitation of upper extremities. Parker, Mountain and Hammerton (2011) described in their study that despite the limited proof, giving extrinsic feedback based on visual or auditory feedback could have a positive influence on the recovery of motor function (Parker et al., 2011). Palacios-Navarro, Albiol-Pérez and García-magariño Garcia (2016) described in their literature study that virtual cueing in a virtual
environment has a positive influence on functional recovery, whereby participants can often also apply this functional recovery in the real world (Palacios-Navarro et al., 2016). The cohort study by Simonsen et al., (2017) was focusing on Microsoft testing Kinect as a therapy form that patients could use independently. This study described the importance of visual and auditory feedback that the therapist provides during the therapy. The conclusion of this study was that the Microsoft Kinect is suitable for independent use. When getting the visual feedback from the Microsoft Kinect, the flexibility and equality of the movement of the participants increased after a few training sessions. At the training session where the participants do not receive visual
20 (Simonsen et al., 2017). For this outcome eight articles were used that looked at the effect of visual feedback in rehabilitation. For the literature review one Randomized controlled trial was used and two literature reviews. These articles are of high levels of evidence. Also four Cohort studies and pilot studies were used and one single group study. The level of evidence is lower for these types of studies, but because of the innovations in technology there is still a lot to research. The relevance for the main questions is that visual feedback has an impact on the function recovery in stroke patients. There is still the question what kind of visual feedback is most effective and what the effect of visual feedback is on the apparatus. See appendix 2 for more detailed findings.
4.1.3 What is the added value of error in motor learning?
The following was found: in EA, the computer singles out and magnifies errors in a patient's movement from a desired trajectory or alters the visual feedback of the movement trajectory, in order to emphasize visual and sensory feedback. The presence of this error in the visual and haptic systems forces the person to strengthen their control as they counteract the error-driven disturbance to the movements. Although this feedback is sometimes counterintuitive and differs greatly from the standard approach to treatment, several lines of reasoning suggest that
augmenting error may enhance motor learning. First, models and artificial learning systems, such as neural networks, suggest that error drives learning and is believed to be central to adaptation and skill acquisition in human movement. Since intrinsic feedback mechanisms are often impaired after a stroke, providing augmented feedback by making errors more noticeable to the senses, is thought to be beneficial, in that a patient will learn more quickly when the error is larger. In addition, larger errors are likely to increase motivation to learn by making even small errors seem large. Finally, intensifying error can lead to larger signal-to-noise ratios for sensory feedback and self-evaluation (Israely & Carmeli, 2016). Seven articles where Randomized Controlled Trials. One article was a systematic literature review. The designs implicate high levels of evidence and can therefore be seen as reliable sources. See appendix 2 for more detailed findings.
4.2 Results experiment
Ten participants were recruited for the experiment. All participants, three males and seven females with the mean age of 31,8 completed the experiment. During the data-analysis the force line on the x-axis of one participant was different from the other participants, the shape of the force line in the graph was not in the same pattern as the force lines of the other participants and was therefore excluded from the experiment.
The results will be, as described in the method, displayed in graphs. The Y-axis in the graphs represent the difference between the baseline and post effects of the force given by the
participant to the handles in Newton, the X-axis represent a cycle (100%). A cycle is 100% of a forward push movement, from proximal to maximal distal position of the arm made by pushing the handle over the rails. The proximal position of the arm is shown in the graph as 0% and the maximal distal position of the arm is shown as 100%. For the graph all the cycles in a block were collected and made in to one mean cycle. The cycle is divided in five equal parts for the data analysis.
In the legend can be found what blocks are visible in the graphs. The name of the blocks are derived from there representative block and the condition that they are from;
- Block_ 7F: Block 7 of the post effects in condition 1 with visual feedback. - Block_8F: Block 8 of the post effects in condition 1 with visual feedback. - Block_7WF: Block 7 of the post effects in condition 2 without visual feedback. - Block_8WF: Block 8 of the post effects in condition 2 without visual feedback. Block 7 and 8 form together the post effects, since these blocks follow the EA block.
F= With Visual Feedback, WF= Without Visual Feedback
Graph 1: Forward force in the left handle Graph 2: Forward force in the right handle
In graph 1 and 2 non-parametric statistics reveal significant differences for values averaged from 0-20% between visual feedback (VF) and without visual feedback (WF) conditions on both sides for blocks 7. The significant differences are displayed in the graph by the asterisks. The differences from the baseline are greater for the condition WF condition at this period (0-20%). No difference is seen for blocks 8.
From the values averaged from 81-100% of the pushing tasks, a difference was also observed for the right handle between VF and WF for blocks 7.
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Graph 3: Percentage of the maximal force during the cycle.
Graph 3 shows whether participants give 15% of their maximum force. Data can be viewed per block, since block 7 and 8 are both displaying the post effects it did not matter which block was used in the graph, for this reason only block 7 was used for analysis. Graph 3 shows that participants give a more consistent strength in the condition without visual feedback (WF) in comparison with the condition with visual feedback (VF). Consistency means that the participants do not fluctuate in the given strength but stay steady. In condition 2 (WF) participants start with more strength, after which they decrease in strength and perform in a consistent way through the rest of the push movement. This in contradiction with condition 1 (VF) where the participants start with less strength but are less consistent during the push movement which can be seen in the graph through the lines that go up in the end. In both conditions participants aren’t exactly at 15% of their maximal strength during the push movement.
4.3 Interpretation of experiment
The results demonstrated the effect of visual feedback on the error augmentation protocol in healthy participants. All participants on both sides (left and right) started giving a lot of power compared to the middle part of the push movement. This could be explained by the fact that the handles must be set in motion. This could be explained by the three laws of Newton. The first law states that an object that stands still wants to stay still and object that moves wants to keep moving. The third law of Newton stated that on every force there is an equal counter force. This makes that an object can’t sink through the floor, because of the counterforce that the floor gives to the object. The first and third law together make the second law. This law describes that when the force on a object is bigger than the counterforce the object will start moving. It takes more force to get an object to start moving or to make it speed up. But when the object is already on the move the force can decrease (Nave, n.d.).
Graph 3 shows that with visual feedback in the end of the cycles the given strength rises in the right hand. This was different in comparison with the post effects without visual feedback. The reason for this might be that without visual feedback participants acted on what their body feels and made a symmetrical push using their joint position, while with visual feedback the
participant gave one final push to reach the target on the screen. This was also found in the literature review about the question what the added value of an error is in motor learning (objective 3).
In both hands during the post effects without visual feedback the given strength by the participants stayed consistent until the end of the cycles once they reached a consistent strength. This is in contradiction with the hypothesis set at the beginning, this will be discussed in the discussion.
4.4 Synthesis
When comparing data found in literature to the results of the experiment it showed that both VR and mirror therapy have a positive effect on the recovery of the arm/hand in people who
suffered stroke by using visual feedback during rehabilitation. In the experiment was found that the group without visual feedback was more consistent in the given strength during the push movement, therefore this result was not in line with the conclusions of the literature reviews when it comes to the effect of the visual feedback.
When comparing data to literature about the value of an error in motor learning the difference was that in the experiment during the post effects visual feedback was taken away. Literature stated that visual feedback forces people to strengthen control because they have error driven disruptions of movement. The data from the experiment showed that without visual feedback participants were more consistent in their movements than the group with visual feedback. The literature study also stated that by amplifying the error it’s easier for the brain to registrate the error and to establish motor learning. However, data from the experiment showed that with visual feedback (so with the amplified error) the strength given by the participants is less consistent in the post effects.
A similarity between found literature and data of the experiment was that the proprioceptors of the muscles and joints were giving the guiding signal for adaptation and learning. This was also
24 found in the experiment, since in the post effects visual feedback was randomized and
participants had to push and rely on the feedback of the proprioception.
It could be that without using visual feedback participants are performing in a more consistent way because they didn’t rely on feedback given on the screen and were more focused on their movements and joints. In the post effects with visual feedback there could be concluded that participants gave one final push to reach the target on the screen in the right hand.
5. Discussion
With the aging population and improved survival after initial injury, the prevalence and incidence of individuals living with disability following cerebral vascular accident (CVA) has increased. These individuals will learn or relearn competencies necessary to perform activities of daily living. Traditionally, the practice of skills provided in neurologic rehabilitation has focused on reducing motor impairment and minimizing physical disability (Bai, Huang, Fei, & Kunz, 2014). New rehabilitative approaches emphasize repetitive, task-specific practice with the affected arm, such as error augmentation (EA). In literature was found that EA achieved positive results on function level (Liu, Li, & Lamontagne,2018). With this knowledge, a device was developed in the lab in Montréal that is based on EA. In this research a research protocol was made to measure the effect of the intervention with the apparatus on different biomedical surfaces of arm/hand function. The current research protocol does not describe the effect visual feedback. So the question was rising of what the effect is of visual feedback on the error augmentation protocol. To answer the question ‘’What is the effect of visual feedback on the error augmentation protocol?” there was made one main objective: ‘’Determine the effect of visual feedback on an error augmentation protocol during an upper extremity task in healthy participants.
To be able to determine the main objective there were made four sub objectives (1: practice research/experiment, 2,3 & 4: literature review):
To determine:
1. The effect of visual feedback on the post effects produced by an error augmentation protocol on an upper extremity task in healthy participants.
2. The effect of visual feedback on the recovery of the upper extremity function in rehabilitation of adults after stroke.
3. The added value of error augmentation in motor learning.
4. The effect of mirror therapy on motor learning in the upper extremities in persons with stroke.
5.1 Implications for further research
It could be that without using visual feedback participants are performing in a more consistent way because they didn’t rely on feedback given on the screen and were more focused on their movements and joints. This is different than expected. When looking into literature about visual feedback it show that participants in most cases benefit from visual feedback in the
rehabilitation process of their upper extremities. However, this thesis showed that without visual feedback participants made their push movement in a more consistent way. Therefore it could be that not receiving visual feedback was beneficial for participants in this thesis. Further research needs to determine if this hypothesis is correct and if these findings apply in more cases.
During the experiment both conditions had error augmentation (EA) with visual feedback. It was only the post effects that were randomized with and without visual feedback. Therefore it could be interesting to do a follow-up study in which visual feedback is randomized during the EA
26 block of 6 minutes. Then can be truly established if visual feedback has an impact on motor learning through EA with the apparatus.
Another aspect of data found in this study was the sudden rise in strength in the post effects at the end of the cycles in participants when receiving visual feedback. It is not clear what could cause this sudden rise. It might be because participants feel they had to meet the target at the end of the cycles and therefore pushed a bit harder. Further research is needed to establish if this hypothesis is true.
Further research will be needed to establish the effects of visual feedback on the long term. Also a bigger sample group will be needed to collect more data to create a more reliable
conclusion. For the main research of the rehabilitation centre in Montréal, it could be interesting to look at the effect of visual feedback in stroke patients who are training according to the EA protocol.
5.2 Limitations
For this thesis the following limitations could be found. There were only ten participants
participating in the research. This was a small sample group, however with the time available in the lab there was only time for this capacity. The demographic characteristics of the sample group were diverse in sex and age. Another limitation of this thesis was that the sample group existed out of employees from IRGLM. This means that in the sample group some participants had more background information than others. This thesis was set up for substantiation of the main research in the rehabilitation center, data was collected randomized and there was a systematic approach for data analysis. This makes that data was collected in a reliable way.
5.3 Recommendations
Occupational therapist should be aware of the effect that visual feedback has on performance during activities. Visual feedback has effect on recovery of function and also in the execution of the activity in rehabilitation settings. There is still a lot to gain for recovery in the area of function recovery, because most of the training is aimed at compensation and learning to deal with limitations instead of recovery and improvement in the use of arm and hand. Stroke survivors learn or relearn competencies necessary to perform activities of daily living. Traditionally, practice of skills provided in neurologic rehabilitation focuses on reducing motor impairment and minimizing physical disability (Langhorne, 2004; Poole, 1991).
During rehabilitation occupational therapist can offer support in every phase after stroke in resuming activities and participation. Occupational therapists are involved in training and retraining of motor skills and motor tasks. The focus of occupational therapists lies more on the compensation what causes that stroke survivors could have more physical impairments than possibly needed. Because of this, new rehabilitative approaches are needed.
Since this research showed that without visual feedback the participants are more consistent in the amount of force they give during post effects, we recommend to execute the experiment in future research with a period with visual feedback at the beginning of the experiment and to continue without visual feedback. We recommend to start with visual feedback, so the participants have a frame of reference for 15% of their maximal strength.
6. Conclusion
This thesis showed that the effect of visual feedback on the error augmentation protocol with the apparatus is that participants were more consistent during the push movement without visual feedback. This is in contradiction with findings in the literature. The literature reviews stated that through visual feedback participants were more motivated and visual feedback had a positive effect on the recovery. The results from the experiment stated that the participant performs a more consistent push movement without visual feedback. This contradiction makes that visual feedback doesn’t always have the same results in rehabilitation. This suggests that
rehabilitation strategies should look at the effect that visual feedback has on patients with stroke.
Further research will be needed to establish the effects of visual feedback on the long term. Also a bigger sample group will be needed to collect more data to create a more reliable
conclusion. For the main research of the rehabilitation centre in Montréal, it could be interesting to look at the effect of visual feedback with stroke patients. Furthermore, it could be interesting to look at the differences between the condition with and condition without visual feedback during the error augmentation phase in the protocol.
Occupational therapist should be aware of the effect that visual feedback has on the
performance during activities. Visual feedback has effect on the recovery of function and also in the execution of the activity in rehabilitation settings. There is still a lot to gain for recovery in the area of function recovery, because most of the training is aimed at compensation and learning to deal with the limitations instead of recovery and improvement in the use of arm and hand. Stroke survivors will learn or relearn competencies necessary to perform activities of daily living. Traditionally, the practice of skills provided in neurologic rehabilitation has focused on reducing motor impairment and minimizing physical disability (Langhorne, 2004; Poole, 1991).
During rehabilitation occupational therapists can offer support in every phase after a stroke in resuming activities and participation. Occupational therapists are involved in training and retraining of motor skills and motor tasks. The focus of occupational therapists lies more on the compensation what causes that stroke survivors could have more physical impairments than possibly needed. Because of this, new rehabilitative approaches are needed.
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