Eva Swinnen

Treadmill Training in Multiple Sclerosis: Can Body Weight Support or Robot Assistance Provide Added Value? A Systematic Review

Purpose. This systematic review critically analyzes the literature on the effectiveness of treadmill training (TT), body-weight-supported TT (BWSTT), and robot-assisted TT (RATT) in persons with multiple sclerosis (MS), with focus on gait-related outcome measurements. Method. Electronic databases (Pubmed, Pedro, Web of Science, and Cochrane Library) and reference lists of articles and narrative reviews were searched. Pre-, quasi- and true-experimental studies were included if adult persons with MS were involved in TT, BWSTT, or RATT intervention studies published before 2012. Descriptive analysis was performed and two researchers scored the methodological quality of the studies. Results. 5 true- and 3 preexperimental studies (mean quality score: 66%) have been included. In total 161 persons with MS were involved (TT, BWSTT, or RATT, 6–42 sessions; 2–5x/week; 3–21 weeks). Significant improvements in walking speed and endurance were reported. Furthermore, improvements of step length, double-support time, and Expanded Disability Status Scale were found. Conclusions. There is a limited number of published papers related to TT in persons with MS, concluding that TT, BWSTT, and RATT improve the walking speed and endurance. However, it is not clear what type of TT is most effective. RCTs with larger but more homogeneous populations are needed.

Does Robot-Assisted Gait Rehabilitation Improve Balance in Stroke Patients? A Systematic Review

Abstract The aim of this systematic review was to summarize the improvements in balance after robot-assisted gait training (RAGT) in stroke patients. Two databases were searched: PubMed and Web of Knowledge. The most important key words are “stroke,” “RAGT,” “balance,” “Lokomat,” and “gait trainer.” Studies were included if stroke patients were involved in RAGT protocols, and balance was determined as an outcome measurement. The articles were checked for methodological quality by 2 reviewers (Cohen’s κ = 0.72). Nine studies were included (7 true experimental and 2 pre-experimental studies; methodological quality score, 56%-81%). In total, 229 subacute or chronic stroke patients (70.5% male) were involved in RAGT (3 to 5 times per week, 3 to 10 weeks, 12 to 25 sessions). In 5 studies, the gait trainer was used; in 2, the Lokomat was used; in 1 study, a single-joint wearable knee orthosis was used; and in 1 study, the AutoAmbulator was used. Eight studies compared RAGT with other gait rehabilitation methods. Significant improvements (no to large effect sizes, Cohen’s d = 0.01 to 3.01) in balance scores measured with the Berg Balance Scale, the Tinetti test, postural sway tests, and the Timed Up and Go test were found after RAGT. No significant differences in balance between the intervention and control groups were reported. RAGT can lead to improvements in balance in stroke patients; however, it is not clear whether the improvements are greater compared with those associated with other gait rehabilitation methods. Because a limited number of studies are available, more specific research (eg, randomized controlled trials with larger, specific populations) is necessary to draw stronger conclusions.

Methodology of electromyographic analysis of the trunk muscles during walking in healthy subjects: a literature review.

PURPOSE To review and discuss the literature about the use of trunk muscle electromyography - including the use of surface or fine-wire electrodes, site of application and muscle selection - during gait analysis in healthy subjects. METHODS The databases Pubmed, Web of Knowledge and Cochrane Library were searched. Articles were included when EMG activity of at least one trunk muscle was measured in healthy subjects during walking. RESULTS In the 33 selected articles 491 healthy subjects walked with different velocities on a treadmill and/or overground. The activity of the M. erector spinae, M. multifidus, M. obliquus externus and internus, M. rectus abdominus, M. trapezius, M. latissimus dorsi, M. transversus abdominus, M. iliopsoas and M. quadrates lumborum was measured. Twenty-nine studies used surface electrodes, one study fine-wire electrodes, and the other three studies used a combination. There is no consensus on the exact placement site of the electrodes. CONCLUSION Surface electrodes were used more often than fine-wire electrodes and the descriptions of the electrode locations were mostly vague and not consistent among the different studies. There is need for further research to make specific recommendations about the type of electrodes in combination with the optimal locations of application of these electrodes.

Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support). Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force) and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

Walking with robot assistance: the influence of body weight support on the trunk and pelvis kinematics.

Abstract Purpose: The goal was to assess in healthy participants the three-dimensional kinematics of the pelvis and the trunk during robot-assisted treadmill walking (RATW) at 0%, 30% and 50% body weight support (BWS), compared with treadmill walking (TW). Methods: 18 healthy participants walked (2 kmph) on a treadmill with and without robot assistance (Lokomat; 60% guidance force; 0%, 30% and 50% BWS). After an acclimatisation period (four minutes), trunk and pelvis kinematics were registered in each condition (Polhemus Liberty™ [240 Hz]). The results were analysed using a repeated measures analysis of variance with Bonferroni correction, with the level of suspension as within-subject factor. Results: During RATW with BWS, there were significantly (1) smaller antero-posterior and lateral translations of the trunk and the pelvis; (2) smaller antero-posterior flexion and axial rotation of the trunk; (3) larger lateral flexion of the trunk; and (4) larger antero-posterior tilting of the pelvis compared with TW. Conclusions: There are significant differences in trunk and pelvis kinematics in healthy persons during TW with and without robot assistance. These data are relevant in gait rehabilitation, relating to normal balance regulation. Additional research is recommended to further assess the influence of robot assistance on human gait. Implications for Rehabilitation The trunk and pelvis moves in a different way during walking with robot assistance. The data suggest that the change in movement is due to the robot device and the harness of the suspension system more than due to the level of suspension itself.

Robot-assisted walking with the Lokomat: the influence of different levels of guidance force on thorax and pelvis kinematics.

BACKGROUND Little attention has been devoted to the thorax and pelvis movements during gait. The aim of this study is to compare differences in the thorax and pelvis kinematics during unassisted walking on a treadmill and during walking with robot assistance (Lokomat-system (Hocoma, Volketswil, Switzerland)). METHODS 18 healthy persons walked on a treadmill with and without the Lokomat system at 2kmph. Three different conditions of guidance force (30%, 60% and 100%) were used during robot-assisted treadmill walking (30% body weight support). The maximal movement amplitudes of the thorax and pelvis were measured (Polhemus Liberty™ (Polhemus, Colchester, Vermont, USA) (240/16)). A repeated measurement ANOVA was conducted. FINDINGS Robot-assisted treadmill walking with different levels of guidance force showed significantly smaller maximal movement amplitudes for thorax and pelvis, compared to treadmill walking. Only the antero-posterior tilting of the pelvis was significantly increased during robot-assisted treadmill walking compared to treadmill walking. No significant changes of kinematic parameters were found between the different levels of guidance force. INTERPRETATION With regard to the thorax and pelvis movements, robot-assisted treadmill walking is significantly different compared to treadmill walking. It can be concluded that when using robot assistance, the thorax is stimulated in a different way than during walking without robot assistance, influencing the balance training during gait.

Trunk kinematics during walking in persons with multiple sclerosis: The influence of body weight support

BACKGROUND Although body weight supported (BWS) treadmill training (TT) leads to some improvements in walking ability, it has not been proven that it is more effective than other walking therapies in persons with multiple sclerosis (PwMS). One possible explanation could be that BWSTT focuses on the cyclic movement of the lower extremities while the trunk is passively suspended in the harness. OBJECTIVE This study aimed to assess the 3 dimensional trunk and pelvis movements during BWS treadmill walking. METHODS 14 PwMS and 14 healthy persons (8 male/20 female; age 23 to 59 years) walked with 0%, 10%, 20%, 30%, 50% and 70% BWS. After a familiarization period, kinematic electromagnetic tracking (Polhemus Liberty™ 240/16) of the trunk and pelvis movements was applied. Statistical analysis consisted of a repeated measures ANOVA with simple contrasts (SPSS 20). RESULTS This study shows that BWS walking leads in general to smaller maximum trunk and pelvis movement amplitudes compared with walking without BWS, this with exception of the pelvis anterior-posterior movement in healthy subjects. CONCLUSION These data help to identify and isolate the effect of different BWS levels in PwMS and in healthy persons and suggest to use BWS lower than 30% for treadmill training.

The immediate effects of robot-assistance on energy consumption and cardiorespiratory load during walking compared to walking without robot-assistance: a systematic review

Abstract Purpose: The integration of sufficient cardiovascular stress into robot-assisted gait (RAG) training could combine the benefits of both RAG and aerobic training. The aim was to summarize literature data on the immediate effects of RAG compared to walking without robot-assistance on metabolic-, cardiorespiratory- and fatigue-related parameters. Methods: PubMed and Web of Science were searched for eligible articles till February 2016. Means, SDs and significance values were extracted. Effect sizes were calculated. Results: Fourteen studies were included, concerning 155 participants (85 healthy subjects, 39 stroke and 31 spinal cord injury patients), 9 robots (2 end-effectors, 1 treadmill-based and 6 wearable exoskeletons), and 7 outcome parameters (mostly oxygen consumption and heart rate). Overall, metabolic and cardiorespiratory parameters were lower during RAG compared to walking without robot-assistance (moderate to large effect sizes). In healthy subjects, when no body-weight support (BWS) was provided, RAG with an end-effector device was more energy demanding than walking overground (p > .05, large effect sizes). Conclusions: Generally, results suggest that RAG is less energy-consuming and cardiorespiratory stressful than walking without robot-assistance, but results depend on factors such as robot type, walking speed, BWS and effort. Additional research is needed to draw firm conclusions. Implications for Rehabilitation Awareness of the energy consumption and cardiorespiratory load of robot-assisted gait (RAG) training is important in the rehabilitation of (neurological) patients with impaired cardiorespiratory fitness and patients who are at risk of cardiovascular diseases. On the other hand, the integration of sufficient cardiometabolic stress in RAG training could combine the effects of both RAG and aerobic training. Energy consumption and cardiorespiratory load during walking with robot-assistance seems to depend on factors such as robot type, walking speed, body-weight support or amount of effort. These parameters could be adjusted in RAG rehabilitation to make RAG more or less energy-consuming and cardiorespiratory stressful. Overall, short duration exoskeleton walking seems less energy-consuming and cardiorespiratory stressful than walking without robot-assistance. This might implicate that the exercise intensity is safe for (neurological) patients at risk of cardiovascular diseases. How this changes in extended walking time is unclear.

Body weight support during robot-assisted walking: Influence on the trunk and pelvis kinematics

BACKGROUND Efficacy studies concerning robot assisted gait rehabilitation showed limited clinical benefits. A changed kinematic pattern might be responsible for this. Little is known about the kinematics of the trunk and pelvis during robot assisted treadmill walking (RATW). OBJECTIVE The aim of this study was to assess the trunk and pelvis kinematics of healthy subjects during RATW, with different amounts of body weight support (BWS) compared to regular treadmill walking (TW). METHOD Eighteen healthy participants walked on a treadmill, while kinematics were registered by an electromagnetic tracking device. Hereafter, the kinematics of pelvis and trunk were registered during RATW (guidance force 30%) with 0%, 30% and 50% BWS. RESULTS Compared to TW, RATW showed a decrease in the following trunk movements: axial rotation, anteroposterior flexion, lateral and anteroposterior translation. Besides, a decrease in lateral tilting and all translation of the pelvis was found when comparing RATW with TW. Furthermore, the anteroposterior tilting of the pelvis increased during RATW. CONCLUSION In general, there was a decrease in trunk and pelvis movement amplitude during RATW compared with regular TW. Though, it is not known if these changes are responsible for the limited efficacy of robot assisted gait rehabilitation. Further research is indicated.

Trunk muscle activity during walking in persons with multiple sclerosis: the influence of body weight support.

BACKGROUND Although the trunk is important for maintaining balance during walking only very limited information about the trunk muscle activity during walking with body weight support (BWS) is reported in literature. OBJECTIVE The aim of this study was to measure the effect of BWS on the trunk muscle activity during treadmill walking. METHODS 14 persons with multiple sclerosis and 14 healthy persons walked on a treadmill with 0%, 10%, 20%, 30%, 50% and 70% BWS. Bilateral EMG measurements (surface electrodes) on the m. rectus abdominis, m. obliquus externus, m. erector spinae and m. multifidus were performed. The maximal muscle activation was presented as a percentage of a performance related reference contraction. A repeated measures ANOVA with simple contrasts was applied (SPSS20). RESULTS In general when comparing walking with BWS with walking with 0% BWS there is an increase in m. obliquus externus activity and a decrease in back muscle activity. With increasing percentages of BWS an increase in activity of the abdominal muscles and a decrease in back muscle activity was found, with most changes in high percentages BWS. CONCLUSION Based on the results, it is recommended to decrease the percentage BWS as fast as possible beneath 30% BWS.