|Year : 2016 | Volume
| Issue : 4 | Page : 163-168
Neurorehabilitation in paraplegic patients with an active powered exoskeleton (Ekso)
Paolo Milia1, Federico De Salvo1, Marco Caserio1, Tyler Cope2, Patti Weber2, Caroline Santella2, Stefano Fiorini3, Giacomo Baldoni1, Riccardo Bruschi1, Benedetta Bigazzi3, Stefano Cencetti1, Marco Da Campo3, Prospero Bigazzi3, Mario Bigazzi3
1 Prosperius Institute, Neurorehabilitation and Robotic Area, University of Perugia, Umbertide, Italy
2 Elon University, DPTE, Elon North Carolina, USA
3 Prosperius Group, University of Florence, Florence, Italy
|Date of Web Publication||3-Mar-2017|
Neurorehabilitation and Robotic Area, Prosperius Institute, University of Perugia, Umbertide
Source of Support: None, Conflict of Interest: None
Background and Objectives: Spinal cord injury (SCI) is a severe disease where the patients lost the body function below the level of lesion. Neurorehabilitative exercise leads to improvements in physical functions such as strength, range of motion, transfers, wheelchair mobility, and gait. The aim of this study is to evaluate the impact of overground gait training using an active powered exoskeleton. Materials and Methods: Patients affected of SCI admitted to our rehabilitation unit have been studied. We used an active powered exoskeleton (Ekso). Training occurred each day for 5 days a week for a total of 4 weeks. Patients were trained for at least twenty sessions, with a duration of 45–60 min each session. Patients were scored with the 6 min walking test (6MWT) before and after treatment to evaluate the movement and Ashwort scale was used to test spasticity. Psychological tests were also performed to focus on depression (Beck Depression Inventory) and on self-perception (Body Uneasiness Test-A). Results: Thirteen patients were studied (mean age 31 ± 10.4; ten males and three females), who were affected by SCI with motor complete/incomplete lesions (seven complete, six incomplete), according to the American Spinal Injury Association guidelines. All patients completed the overground gait training for all 4 weeks without collateral effects. The motor recovery evaluated with the 6MWT in incomplete motor patients described a statistical significant recovery in terms of meters and absence of rest, especially in thoracic and lumbar level lesions (48/114 m [improvement 137.5%]; 98/214 m [improvement 118.37%], P < 0.05). We did not find any difference in terms of spasticity using the Ashworth Scale. After the treatment, we found in all patients a great improvement in mood disorders and body perception. Conclusions: The overground training with the exoskeleton is a promising therapeutical approach for SCI patients, which can increase both motor and psychological aspects.
Keywords: Exoskeleton, rehabilitation, spinal cord injury
|How to cite this article:|
Milia P, De Salvo F, Caserio M, Cope T, Weber P, Santella C, Fiorini S, Baldoni G, Bruschi R, Bigazzi B, Cencetti S, Da Campo M, Bigazzi P, Bigazzi M. Neurorehabilitation in paraplegic patients with an active powered exoskeleton (Ekso). Digit Med 2016;2:163-8
|How to cite this URL:|
Milia P, De Salvo F, Caserio M, Cope T, Weber P, Santella C, Fiorini S, Baldoni G, Bruschi R, Bigazzi B, Cencetti S, Da Campo M, Bigazzi P, Bigazzi M. Neurorehabilitation in paraplegic patients with an active powered exoskeleton (Ekso). Digit Med [serial online] 2016 [cited 2018 Mar 23];2:163-8. Available from: http://www.digitmedicine.com/text.asp?2016/2/4/163/201273
| Introduction|| |
A spinal cord injury (SCI) is a traumatic event that results in permanent deficits such as changes in sensation, strength, and other physiological bodily functions below the level of the lesion. Data from the World Health Organization suggest that the total international incidence of SCI is between 250,000 and 500,000 annually, which is equivalent to 40–80 new cases per million population per year. Etiologically, SCI can be either traumatic SCI (TSCI) or nontraumatic SCI (NTSCI), the incidence of which varies by age and by sex. In both cases, the incidence is higher among males than females.
The most common causes of TSCI, which produce a lesion of the spinal cord through direct deformation, are road traffic accidents, falls, and violence. Following the initial insult, secondary hemorrhage, inflammation and swelling, neurotoxicity, or glial scarring can exacerbate the initial traumatic injury. Studies suggest the most common causes of NTSCI are a result of pathological conditions, such as neoplasm and degenerative conditions, vascular conditions, and autoimmune disorders.,, Recent increases in the prevalence of NTSCI have been attributed to aging demographics.
SCI is classified based on the severity of the lesion as either a complete or an incomplete SCI. A complete lesion results in the loss of all sensory and motor function below the level of the lesion, including the S4–S5 reflex. Complete lesions occur in approximately 54.7% of TSCI cases and 25.3% of NTSCI cases. Incomplete lesions will result in the individual retaining residual motor and/or sensory function below the level of the lesion and occur in approximately 45.3% of TSCI cases and 74.7% of NTSCI cases.
Depending on the location of the lesion, an individual will have physical and physiological impairments consistent with quadriplegia or paraplegia. Quadriplegia, defined as paralysis resulting in partial or complete loss of muscle use in all four limbs and torso, has an incidence of 36.7% of TSCI cases and 22.6% of NTSCI cases. Paraplegia, defined as partial or complete loss of muscle function in the lower limbs, has an incidence of 64.3% of TSCI cases and 77.4% of NTSCI cases.
Early acute management is crucial to the prognosis of SCI and acute interventions include, but are not limited to, emergency transport, management of vital functions, spinal immobilization, imaging, surgical procedures, and pharmacological interventions. Proceeding acute care of SCI, two important long-term interventions to consider in the management of SCI are neurorehabilitative training as well as psychosocial interventions.
Neurorehabilitative exercise and training, including physical therapy, occupational therapy, and the use of locomotor robotics, may provide neurorehabilitative, neuroprotective, and neuroregenerative effects for the SCI patient., Exercise has been theorized to provide neuroprotective and neuroregenerative effects in the central nervous system that enhance the performance of several biochemical processes which aid in protein synthesis and cellular survival for neuronal cells.,,
Physical therapy, the primary method of neurorehabilitative exercise for patients with SCI, has been demonstrated to provide improvements in physical functions such as strength, range of motion, transfers, wheelchair mobility, and gait. Locomotor training, using systems such as body-weight support treadmill training, Lokomat, and exoskeleton, has been shown to influence neuroplasticity and neural motor output. Locomotor system research studies highlight the importance of intensive, task-specific gait retraining exercises for improving walking function due to the repetition of movements utilized during gait.,
The SCI deficits pose many psychosocial challenges. In comparison with the general population, individuals with SCI report higher levels of distress and lower levels of life satisfaction. The physical manifestations of SCI, such as the loss of strength, mobility, and bodily control, may lead to many psychosocial challenges, which can include the effect of institutionalism, loss of independence, changes in social role/lifestyle, anxiety, depression, and in some instances, suicide ideation. Research has shown that up to 40% of patients with SCI are diagnosed with a psychiatric disorder.
Intervention to reintegrate and readjust a patient with SCI back into society, as well as ensuring the patient has accessible and appropriate psychological intervention, is important to improve life satisfaction and levels of distress. To accomplish this reintegration, a team-oriented and interdisciplinary approach that includes physical therapy, occupational therapy, psychiatry, clinical psychology, and social workers is essential for optimal results. Interdisciplinary teamwork is an integral part of developing a good understanding of the psychosocial obstacles and challenges that patients with SCI may encounter.
The aim of this study is to assess the impact of robotic, overground locomotors training on patients with motor complete and motor incomplete SCI using the active, powered, and lower limb exoskeleton Ekso (Ekso Bionics). Moreover, we performed a psychological analysis to test the impact of overground gait training problems in SCI patients.
| Materials and Methods|| |
We have investigated thirteen patients (mean age 31 ± 10.4; ten males and three females) affected by SCI with motor complete/incomplete lesions (seven complete, six incomplete), according to the American Spinal Injury Association (ASIA) guidelines. Inclusion/exclusion criteria were strictly followed [Table 1] to guarantee safety and avoid collateral effects.
The seven patients with complete lesions were classified as ASIA A, whereas the remaining six patients with incomplete lesions as ASIA C. Neurological level injury of lesion varied from C4 to L5 [Table 2] and [Diagram 1].
We used the Ashworth Scale to measure the level of spasticity only at the baseline (before treatment), and the 6 min walking test (6MWT) for incomplete spinal patients before treatment to assess the level of functional motor recovery after treatment. A physiotherapist (PT) administered these tests.
Furthermore, the psychological approach was focused, especially on depression, using the Beck Depression Inventory (BDI) scale and on self-perception of the body after the neurological illness, using the Body Uneasiness Test (BUT-A). A neuropsychologist before and after the treatment administered these tests.
Ekso (Ekso Bionics) is a mobile exoskeleton that is intended for rehabilitation and mobility of individuals with neurological motor diseases. The device is designed to adjust easily to fit users ranging in height between 157 cm and 195 cm. The individualized fit is made using measurements at the thigh and shank to adjust length, and at the hips to adjust frontal plane width. The device is attached to the user's torso with backpack style shoulder harnessing and a torso brace.
Ekso is electrically powered by two electric motors at the knee and hip joints of either leg of the user.
The device operates using a number of important sensors. Some of these sensors are dedicated to maintaining proper function of the mechanical system, and some are devoted to determining the user intent while using the device. The user-focused sensors are foot pressure sensors at the heel and toe of both feet to determine the forces between the user and the ground at those locations. The control code in the device behaves by creating an internal estimate of the individual's current position and then coordinating the motion of the four actuated degrees of freedom to take the desired motion. The Ekso can stand from a seated position, walk, and sit down.
The desired motion is specified through an attached user interface that can be used by the therapist. The device offers three available modes of training: “FirstStep,” “ProStep,” and “ActiveStep” (explained in the section “Procedure”).
The device has a Quality Management System Certificate of Registration to ISO 13485:2003 (Medical Devices – Quality management systems – Requirements for regulatory purposes) and the CE Marking Certificate number CE 584311 [Figure 1].
Patients consecutively admitted to our Neurorehabilitation Hospital underwent a clinical assessment for the gait training with exoskeleton Ekso. They were evaluated by a neurologist to confirm the injury level, hemodynamic stability, and skin integrity and immediately after by two licensed PT who have been properly trained and have level 3 certification as assessed by the Ekso clinical trainers.
Training occurred each day for 5 days/week for a total of 4 weeks. Patients were trained for at least twenty sessions, with a duration of 45–60 min each session.
During the procedure, the patients were progressively practiced with the Ekso's three available modes of training: the “First Step” mode is used early in training where the therapist manually triggers the steps of the user using the remote control and number display; the “ProStep” mode allows advanced users to initiate an Ekso step by achieving the proper lateral and forward shift for the Ekso to automatically take the next step; and the “ActiveStep” mode allows participants to trigger their own steps through buttons on the smart crutch/walker.
A training mode is available and can be used as participant transitions from walking with PT initiated steps versus self-initiated steps either in the ActiveStep or ProStep modes. The training mode consists of auditory feedback when a participant achieves the desired forward and/or lateral weight shift in preparation for step initiation.
There also exists a program, naming “Variable Assist,” which allows clinicians to augment their patients' strength, and provides the ability to strategically target deficient aspects of their gait. It has been also used for stroke patients.
At the end of the training, we tested the different progression of patients through the different training programs (First-Active-ProStep), number of steps overground, impact on functional motor aspects in incomplete patients, and the motor recovery influence on psychological variables.
| Results|| |
All patients completed the overground gait training for all 4 weeks without collateral effects. All patients passed the different training programs (First-Active-Prostep) and at the end of the training can control the exoskeleton independently, although the presence of a PT was always guaranteed for clinical and safety reasons. Patients affected by a higher-level of lesion took more time to pass from the first to the next training programs due to more difficulty correctly shifting their weight and balance. At the end of the training, the average daily number of steps for each session varied from 50 to 300. Patients affected by a complete motor deficit with a thoracic lesional level at the end of the training completed more than 12.000 steps overground and reported a consistently “light feeling” after training. The motor recovery evaluated with the 6MWT in incomplete motor patients described a significant recovery in terms of meters and absence of rest especially in thoracic and lumbar level lesions (48/114 m [improvement 137.5%]; 98/214 m, [improvement 118.37%]; P < 0.05) [Table 3] and [Figure 2].
|Figure 2: Motor recovery in incomplete patients (AISC: incomplete motor deficit), 6MWT: Six minutes walking test, NLI: Neurological Level of Injury|
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Two patients affected from complete lesions after the gait training can walk using the knee ankle foot orthosis for at least 16 m in a L4 level patient and 9 m in a C4 level patient.
We did not find any difference in terms of spasticity using the Ashworth Scale, although the patient described a better feeling regarding the muscular tone.
We found an excellent therapeutic property of the exoskeleton using the BDI. All patients improved the BDI score after 4 weeks (average 18.2 admission; 14 after 4 weeks). Particularly, the second items after 4 weeks were improved to a score of 0 for almost all the patients, revealing that the patients had a positive vision about their future. Furthermore, the body perception calculated using the BUT-A described beneficial effects using the Ekso with an improvement of average between admission and after 4 weeks of training (100-81, respectively) [Table 4].
| Discussion|| |
The overground gait training in complete/incomplete SCI using the exoskeleton Ekso seems to be safe and easy to use. In fact, the first positive aspect that comes to mind is the easy way to wear the robotic suit that takes approximately 2.5 min of setup for all types of patients. This is an easy way to start a rehab session with patients that normally need a high grade of care. The same can be considered regarding the different training gait programs that have been successfully passed by all patients also from patients with higher-level spinal cord lesions. Due to the ability of the robotic legs to abduct, the patient can easily be seated on a chair to then have the robotic legs adduct and attach. The other aspect is the torso that allows patients with cervical lesion to be perfectly coordinated with the exoskeleton and have a safe control of trunk.
The number of steps that all patients made overground using Ekso is really consistent if we consider that we are speaking about spinal cord patients that usually are confined only to a wheelchair. This is important because the health benefit derived from exercise has already been shown to be effective, especially for muscular tone, regular bowel dysfunction, prevention of obesity and reduction of diabetes in patients with SCI.
Our results showed an improvement of the 6MWT after gait training with Ekso in incomplete patients with a statistical significance [Figure 2]. This aspect about walking restoration is the priority, considering that Burns et al. in 1997 described that almost 20% with motor incomplete tetraplegia fail to become ambulatory. Considering our results, we believe that the exoskeleton may be used to improve locomotion and all those factors that can impact locomotion such as strength, speed, balance and endurance in incomplete patients. On the other hand, for complete SCI, the exoskeleton has primarily the role of diminishing the impact of decreased mobility and diminishing the related risk factors as previously assessed. The primary goal is to use this robotic device like orthosis easily at home to restore and improve the quality of life.
The quality of life improvements that patients felt occurred immediately after they started to walk again on the ground using the exoskeleton. All patients were positive and the emotional aspects showed overwhelmingly clear benefits. Our results showed a positive impact on mood disorders as assessed by the BDI and patients started to feel a different approach about their wounded body as tested with BUT-A test. The data are in contrast with the group of Esquenazi and Packel  where the psychological effects were not sustained after discontinuation of training. Our positive results may also be justified by the fact that our patients were trained 5 days/week for 4 weeks, thus giving the patients the real feeling of improvement.
Although there were evident limitations of our results, such as the small number of patients, the lack of randomization, the need of longer follow-up and many other limitations. This study may represent an important exploration about the evident role that Ekso can play in rehabilitation and in the near future, urban application. The main goal is to use this device in a real setting where patients can restore part of their activities of daily living.
We are still working and analyzing new patients and the application of Ekso to different neurologic causes of gait dysfunction such as stroke, Parkinson, and demyelinating diseases.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]