Electromechanical‐assisted training for walking after stroke
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The main objective of this systematic review is to investigate the effect of automated electromechanical and robotic‐assisted gait training devices (with body weight support) in
improving walking after stroke. The primary outcomes will be recovery of independent walking, and the secondary outcomes will be improvement in walking speed and gait capacity and recovery in ability to perform activities of daily life.
Background
A stroke is a sudden, nonconvulsive loss of neurological function due to an ischemic or hemorrhagic intracranial vascular event (WHO 2006). In general, cerebrovascular accidents are classified by anatomic location in the brain, vascular distribution, etiology, age of the affected individual, and hemorrhagic versus nonhemorrhagic nature (Adams 1993). Stroke is a leading cause of death and a leading cause of serious, long‐term disability in adults. Three months after stroke, 20% of patients remain wheelchair bound, and approximately 70% walk at reduced velocity and capacity (Jorgensen 1995). Restoration of walking ability and gait rehabilitation is therefore highly relevant for patients who are unable to walk independently after stroke, as well as for their relatives. To restore gait, modern concepts of rehabilitation favour a task‐specific repetitive approach (Carr 2003). In recent years it has also been shown that higher intensities of walking practice result in better outcomes for patients after stroke (Kwakkel 1999; Van Peppen 2004).
In recent years treadmill training, with and without body weight support, was introduced for the rehabilitation of patients after stroke. Treadmill training with partial body weight support enables the repetitive practice of complex gait cycles for patients following stroke. One disadvantage of treadmill training, however, is the necessary effort by therapists to set the paretic limbs and to control weight shift, thereby possibly limiting the therapy intensity. Intended to reduce the therapist's exertions, automated electromechanical gait machines were developed, consisting either of a robot‐driven exoskeleton orthosis (Colombo 2000) or an electromechanical solution with two driven foot plates simulating the phases of gait (Hesse 2003; Schmidt 2005).
One example of automated electromechanical gait rehabilitation is the 'Lokomat' (Colombo 2000). A robotic gait orthosis combined with a harness‐supported body weight system is used in combination with a treadmill. However, the main difference from treadmill training is that the patient's legs are guided by the robotic device according to a pre‐programmed gait pattern. A computer‐controlled robotic gait orthosis guides the patient. The process of gait training is at the very least automated.
A second example is the 'Gait Trainer' which is based on a double crank and rocker gear system (Hesse 1999). In contrast to a treadmill, the electromechanical 'Gait Trainer' consists of two footplates positioned on two bars, two rockers and two cranks, which provide the propulsion. The harness‐secured patient is positioned on the footplates, which symmetrically simulate the stance and the swing phases of walking (Hesse 1999). A servo‐controlled motor guides the patient during walking exercise. Vertical and horizontal movements of the trunk are controlled in a phase‐dependant manner. Again, the main difference to treadmill training is that the process of gait training is automated and supported by an electromechanical solution.
Both electromechanical devices, the 'Lokomat' and the 'Gait Trainer', can be used to give non‐ambulatory patients intensive practice of complex gait cycles. The advantage of these electromechanical devices, as compared to treadmill training with partial body weight support, may be the reduced effort for therapists as they no longer need to set the paretic limbs or assist trunk movements (Werner 2002).
However, until now scientific evidence for the benefits of these technologies, which could justify their relative high cost, is lacking. Additionally, until now there has been no systematic evaluation concerning the effectiveness of this electromechanical task‐oriented approach. Therefore, a systematic review of the available literature is required to assess effectiveness and acceptability of these electromechanical devices.
Objectives
The main objective of this systematic review is to investigate the effect of automated electromechanical and robotic‐assisted gait training devices (with body weight support) in
improving walking after stroke. The primary outcomes will be recovery of independent walking, and the secondary outcomes will be improvement in walking speed and gait capacity and recovery in ability to perform activities of daily life.
Methods
Criteria for considering studies for this review
Types of studies
We will include only randomised, controlled trials and randomised controlled cross‐over trials (only the first period will be analysed as a parallel group trial) in this review.
Types of participants
We will include studies with participants of any gender over 18 years of age after stroke (using the World Health Organization (WHO) definition of stroke, or a clinical definition of stroke when the WHO definition is not specifically stated).
Types of interventions
We will include all trials that evaluate robotic‐assisted or automated electromechanical gait training devices, or both, for regaining and improving walking after stroke. Automated electromechanical devices will be defined as any device with an electromechanical solution designed to assist (by supporting body weight and automating the walking therapy process) stepping cycles in patients after stroke. This category includes any mechanical or computerised device, or both, designed to improve walking function. Because development of automated electromechanical devices such as robots is ongoing, we will also include newly‐developed electromechanical devices for gait training after stroke. We will not include non‐weight‐bearing interventions such as non‐interactive devices that delivered continuous passive motion only in this review (Nuyens 2002). Trials testing the effectiveness of treadmill training or other approaches such as repetitive task training in physiotherapy or electrical stimulation will not be included in this review (to prevent duplication with other Cochrane reviews and protocols (such as Moseley 2005).
Types of outcome measures
Regaining walking is a very important goal for patients after stroke (Bohannon 1988). Therefore, we define the primary outcome as the ability to walk independently. We will measure the ability to walk with the Functional Ambulation Category (FAC) (Holden 1984). A FAC score of four or five indicates independent walking over a 15 metre surface irrespective of aids used, such as a cane. A FAC score of less than four indicates dependency in walking (supervision or assistance, or both, must be given in performing walking).
If FAC scores are not reported in the included studies we will use alternative indicators of independent walking such as:
-
a score of three on the ambulation item of the Barthel Index (BI) (Wade 1988); or
-
a score of six or seven for the walking item of the Functional Independence Measure (FIM) (Hamilton 1994); or
-
a 'yes' response to the item 'walking inside, with an aid if necessary (but with no standby help)' or 'yes' to 'walking on uneven ground' in the Rivermead Mobility Index (RMI) (Collen 1991).
Secondary outcomes will be defined as measures of impairments in body structures. As relevant measures of impairments we will use the continuous variables walking speed, walking capacity and the RMI. Additionally, as a secondary outcome, we will use death from all causes.
We will investigate the safety of electromechanical‐assisted gait training devices with the incidence of adverse outcomes such as thrombosis, major cardiovascular events, injuries and pain and any other reported adverse events. To measure the acceptance of electromechanical‐assisted gait training devices in walking therapies we will use, depending on data provided by the study authors, visual analog scales or withdrawal from study, or both, during the study period.
Depending on the above‐stated categories and the availability of variables used in the included trials, all review authors will discuss and reach consensus on which outcome measures should be included in the analysis.
Search methods for identification of studies
We will search the Cochrane Stroke Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, latest issue), MEDLINE (1966 to present), EMBASE (1980 to present), CINAHL (1982 to present), AMED (Allied and Complementary Medicine Database) (1985 to present), SPORTDiscus (1949 to present), the Physiotherapy Evidence database (PEDro) and the engineering databases COMPENDEX (1972 to present) and INSPEC (1969 to present).
The following search strategy will be used for MEDLINE and will be modified for the other databases.
1. exp cerebrovascular disorders/ or brain injuries/ or brain injury, chronic/
2. (stroke$ or cva or poststroke or post‐stroke).tw.
3. (cerebrovasc$ or cerebral vascular).tw.
4. (cerebral or cerebellar or brain$ or vertebrobasilar).tw.
5. (infarct$ or isch?emi$ or thrombo$ or emboli$ or apoplexy).tw.
6. 4 and 5
7. (cerebral or brain or subarachnoid).tw.
8. (haemorrhage or hemorrhage or haematoma or hematoma or bleed$).tw.
9. 7 and 8
10. exp hemiplegia/ or exp paresis/
11. (hempar$ or hemipleg$ or brain injur$).tw.
12. Gait Disorders, Neurologic/
13. 1 or 2 or 3 or 6 or 9 or 10 or 11 or 12
14. physical therapy modalities/ or exercise therapy/ or motion therapy, continuous passive/
15. *exercise/ or *exercise test/
16. robotics/ or automation/ or orthotic devices/
17. body weight/ or weight‐bearing/
18. ((gait or locomot$) adj5 (train$ or therapy or rehabilitat$ or re‐educat$)).tw.
19. (electromechanical or electro‐mechanical or mechanical or mechanised or mechanized or driven).tw.
20. ((body‐weight or body weight) adj3 (support$ or relief)).tw.
21. (robot$ or orthos$ or orthotic or automat$ or computer aided or computer assisted).tw.
22. (bws or harness or treadmill or exercise$ or fitness train$ or Lokomat or Locomat or GaiTrainer or Kinetron).tw.
23. ((continuous passive or cpm) adj3 therap$).tw.
24. or/14‐23
25. gait/ or exp walking/ or locomotion/
26. "Range of Motion, Articular"/
27. recovery of function/
28. (walk$ or gait$ or ambulat$ or mobil$ or locomot$ or balanc$ or stride).tw.
29. 25 or 26 or 27 or 28
30. 13 and 24 and 29
31. limit 30 to humans
Additionally, we will handsearch potentially relevant conference proceedings, screen reference lists and search ongoing trials and research registers. Furthermore, we will contact trialists and researchers in our field of study to identify published, unpublished and ongoing trials not available in the major databases.
Data collection and analysis
Identification of relevant studies
Two review authors (MP and JM) will read the titles of the identified references and will eliminate obviously irrelevant studies based on titles and, when available, abstracts. Two review authors (MP and CW) will independently examine potentially relevant studies using predetermined criteria. These criteria will be: whether the study is a randomised, quasi‐randomised or controlled trial; whether participants are individuals who have had a stroke and interventions are electromechanical devices or driven gait orthosis; and whether walking is measured as an outcome. Studies will be ranked as excluded, included or uncertain using our checklist. Disagreement will be resolved by discussion between the review authors (MP, JM, CW and JK).
Assessment of methodological quality
Two review authors (MP and JK) will score the methodological quality of included studies using the 11‐item PEDro scale (Herbert 1998), which has shown good reliability (Maher 2003) and is available at the Physiotherapy Evidence Database (PEDro). Items are: specification of eligibility criteria; random allocation to groups; concealed allocation; groups similar at baseline; blinding of subjects, therapists and assessors; at least one outcome measurement obtained from more than 85% of participants initially allocated to groups; reporting of between‐group statistical comparisons; reporting of point measures and measures of variability. Disagreement will be resolved by discussion between the review authors.
Statistical analysis
The main outcome of interest, regaining walking function as measured with the FAC, is an ordinal variable. We will dichotomise FAC categories of zero to three as dependent in walking and FAC categories of four and five as success in regaining independent walking. Therefore, the odds ratio (OR) calculated from the proportional odds model can be interpreted as the odds of success in regaining independent walking on the experimental intervention relative to the control. The null hypothesis for the primary outcome is that the OR for regaining walking function with electromechanical gait training versus another gait training intervention is 1. Using The Cochrane Collaboration's Review Manager software (RevMan 4.2), the proportional OR with 95% confidence intervals will be calculated (RevMan 2003).
For interval‐scaled secondary outcomes, weighted mean differences (WMD) will be used. A pooled estimate of the WMD will be calculated, using both the fixed‐effect and the random‐effects models and approximate 95% confidence intervals reported. For the secondary outcome 'death from all causes' we will calculate relative risks (RR) with 95% confidence intervals.
To test for heterogeneity we will use the chi‐squared statistic (alpha level 10%). To quantify inconsistency across studies we will use the I‐squared statistic (alpha level 50%). If there is statistically significant heterogeneity or inconsistency, or both, we will calculate the overall effects using a random‐effects model instead of a fixed‐effect model.
To test the robustness of the results, a sensitivity analysis will be undertaken by incorporating (or leaving out) studies that are assessed to be of lower or ambiguous methodological quality.
We will do a subgroup analysis comparing patients treated in the acute and subacute phase of their stroke (within three month) with patients treated in the chronic phase (more than three months).
For all statistical analyses we will use The Cochrane Collaboration's Review Manager software (RevMan 4.2) (RevMan 2003).
