Domien Gijbels

The Armeo Spring as training tool to improve upper limb functionality in multiple sclerosis: a pilot study

BackgroundFew research in multiple sclerosis (MS) has focused on physical rehabilitation of upper limb dysfunction, though the latter strongly influences independent performance of activities of daily living. Upper limb rehabilitation technology could hold promise for complementing traditional MS therapy. Consequently, this pilot study aimed to examine the feasibility of an 8-week mechanical-assisted training program for improving upper limb muscle strength and functional capacity in MS patients with evident paresis.MethodsA case series was applied, with provision of a training program (3×/week, 30 minutes/session), supplementary on the customary maintaining care, by employing a gravity-supporting exoskeleton apparatus (Armeo Spring). Ten high-level disability MS patients (Expanded Disability Status Scale 7.0-8.5) actively performed task-oriented movements in a virtual real-life-like learning environment with the affected upper limb. Tests were administered before and after training, and at 2-month follow-up. Muscle strength was determined through the Motricity Index and Jamar hand-held dynamometer. Functional capacity was assessed using the TEMPA, Action Research Arm Test (ARAT) and 9-Hole Peg Test (9HPT).ResultsMuscle strength did not change significantly. Significant gains were particularly found in functional capacity tests. After training completion, TEMPA scores improved (p = 0.02), while a trend towards significance was found for the 9HPT (p = 0.05). At follow-up, the TEMPA as well as ARAT showed greater improvement relative to baseline than after the 8-week intervention period (p = 0.01, p = 0.02 respectively).ConclusionsThe results of present pilot study suggest that upper limb functionality of high-level disability MS patients can be positively influenced by means of a technology-enhanced physical rehabilitation program.

Predicting habitual walking performance in multiple sclerosis: relevance of capacity and self-report measures

The objective was to establish the extent to which physical functioning capacity and self-report measures are able to predict the habitual walking performance in ambulatory persons with multiple sclerosis. Fifty persons with multiple sclerosis (Expanded Disability Status Scale, EDSS, 1.5—6.5) were tested on leg muscle strength as well as walking and balance capacity, and completed self-report indices on perceived physical functioning. Habitual walking performance, that is, the real amount of steps that is performed in the customary living environment, was registered by means of an ambulant accelerometer-based monitor during seven consecutive days. Mild (EDSS 1.5—4.0, n = 29) and moderate (EDSS 4.5—6.5, n = 21) multiple sclerosis subgroups were additionally distinguished as predictor variables and values were hypothesized to differ depending on multiple sclerosis severity and concomitant ambulatory function. Multiple regression analyses yielded a single most significant predictor for each (sub)group with other variables making no independent contribution to the variation in habitual walking performance. For the total study sample, this was the 6-Minute Walking Test (R2 = 0.458, p < 0.01). In the mild multiple sclerosis subgroup, the 6-Minute Walking Test was again most predictive, yet to a modest degree (R2 = 0. 187, p = 0.02). In the moderate multiple sclerosis subgroup, the 2-Minute Walking Test explained over half of the variance (R2 = 0.532, p < 0.01). Habitual walking performance is best reflected by longer walking capacity tests. The extent to which it can be predicted based on clinical testing is larger in a multiple sclerosis patient sample with more severe walking disability. Ambulatory monitoring, however, includes aspects of community ambulation not captured in the clinic, and must be considered as an additional outcome for evaluating interventions in multiple sclerosis.

Comparison of the 2- and 6-minute walk test in multiple sclerosis.

The 6-minute walk test (6MWT) is often used to assess walking distance in multiple sclerosis (MS), but can be both time consuming for the investigator and exhausting for people with MS (pwMS). The present report compared the 6MWT scores of 40 ambulatory pwMS with their scores on the shorter 2-minute walk test (2MWT). The 2MWT estimated the 6MWT results with a mean relative error of 5% (R2 = 0.96; p < 0.01). As the last 4-minute period of the 6MWT seems redundant, the 2MWT may be considered as a practical replacement for the 6MWT in routine clinical assessment.

Which walking capacity tests to use in multiple sclerosis? A multicentre study providing the basis for a core set

Background: Many different walking capacity test formats are being used. It is unclear whether walking speed, obtained from short tests, and walking distance, obtained from long tests, provide different clinical information. Objectives: To determine the differential effect of various short and long walk test formats on gait velocity, and the actual relationship between walking speed and walking distance in multiple sclerosis (MS) patients with diverse ambulation status. Methods: A cross-sectional multicentre study design was applied. Ambulatory MS patients (Expanded Disability Status Scale (EDSS) 0–6.5; n = 189) were tested at 11 sites. Short tests consisted of the Timed 25-Foot Walk (static start, fastest speed) and 10-Metre Walk Test (dynamic start, usual and fastest speed). Long tests consisted of the 2- and 6-Minute Walk Tests (fastest speed). Subjects were divided into mild (EDSS 0–4; n = 99) or moderate (EDSS 4.5–6.5; n = 79) disability subgroups. Results: In both subgroups, the start protocol, instructed pace and length of test led to significantly different gait velocities. Fastest walking speed and 6-Minute walking distance showed the strongest correlation (R2 = 0.78 in mild and R2 = 0.81 in moderate MS; p < 0.01). Short tests’ relative estimation errors for 6-Minute walking distance were 8–12% in mildly and 15–16% in moderately affected subjects. Based on the 2-Minute Walk Test, estimation errors significantly reduced to approximately 5% in both subgroups. Conclusions: A single short test format at fastest speed accurately describes an MS patient’s general walking capacity. For intervention studies, a long test is to be considered. We propose the Timed 25-Foot Walk and 2-Minute Walk Test as standards. Further research on responsiveness is needed.

Effects of long-term resistance training and simultaneous electro-stimulation on muscle strength and functional mobility in multiple sclerosis:

Background: Resistance training studies in multiple sclerosis (MS) often use short intervention periods. Furthermore, training efficiency could be optimized by unilateral training and/or electrical stimulation. Objective: To examine the effect(s) of unilateral long-term (20 weeks) standardized resistance training with and without simultaneous electro-stimulation on leg muscle strength and overall functional mobility. Methods: A randomized controlled trial involving 36 persons with MS. At baseline (PRE) and after 10 (MID) and 20 (POST) weeks of standardized (ACSM) light to moderately intense unilateral leg resistance training (RESO, n = 11) only or resistance training with simultaneous electro-stimulation (RESE, n = 11, 100 Hz, biphasic symmetrical wave, 400 µs), maximal isometric strength of the knee extensors and flexors (45°, 90° knee angle) and dynamic (60–180°/s) knee-extensor strength was measured and compared with a control group (CON, n = 14). Functional mobility was evaluated using the Timed Get Up and Go, Timed 25 Foot Walk, Two-Minute Walk Test, Functional Reach and Rivermead Mobility Index. Results: Maximal isometric knee extensor (90°, MID: +10 ± 3%, POST: +10 ± 4%) in RESO and knee flexor (45°, POST: +7 ± 4%; 90°, POST: +9 ± 5%) in RESE strength increased (p < 0.05) compared with CON but RESO and RESE did not differ. Also, impaired legs responded positively to resistance training (unilateral leg strength analysis) and functional reaching increased significantly in RESO (+18%) compared with CON. Dynamic muscle strength and the remaining functional mobility tests did not change. Conclusion: Long-term light to moderately intense resistance training improves muscle strength in persons with MS but simultaneous electro-stimulation does not further improve training outcome.

The relationship between upper leg muscle strength and walking capacity in persons with multiple sclerosis.

Background: In persons with multiple sclerosis (PwMS) resistance training improves muscle strength but effects on walking capacity are inconsistent. Objective: The objective was to determine the relation between different types of upper leg muscle strength measurements and walking capacity in PwMS. Methods: An observational cross-sectional study design was applied. Upper leg muscle strength of 52 PwMS (Expanded Disability Status Scale, EDSS range 1.5–6.5) was measured using isometric (knee extensors and flexors) and isokinetic (knee extensors) dynamometry. Walking capacity was assessed using the Timed 25-Foot Walk, Timed Up and Go and Two Minute Walk Test. Subgroups with mild (EDSS 1.5–4.0, n=31) and moderate (EDSS 4.5–6.5, n=21) ambulatory dysfunction were distinguished, and results were hypothesized to differ depending on multiple sclerosis (MS)-related disability status. Correlation and regression analyses were performed on the data of the most affected leg. Results: Greatest (r: 0.2–0.7) and significant Pearson correlation coefficients were found in the moderate compared to mild MS subgroup. Within knee extensor measurements, it was found that isokinetic endurance strength related best to walking capacity. When comparing maximal isometric strength measurements, knee flexors (r: 0.5–0.7) related better to walking capacity than knee extensors (r: 0.1–0.4). Regression analyses confirmed endurance knee extensor strength (~25 %) and isometric knee flexor strength (~40%) as main predictors for walking capacity. Conclusion: Resistance training protocols may consider inclusion of exercises focusing on endurance knee extensor and isometric knee flexor strength when aiming to enhance walking capacity in persons with moderate ambulatory dysfunction.

Effect of time of day on walking capacity and self-reported fatigue in persons with multiple sclerosis: a multi-center trial

Background: Many persons with multiple sclerosis (PwMS) report increased fatigue in the afternoon and evening compared with the morning. It is commonly accepted that physical capacity also decreases as time of day progresses, potentially influencing the outcomes of testing. Objective: The objective of this article was to determine whether self-reported fatigue level and walking capacity are influenced by time of day in PwMS. Methods: A total of 102 PwMS from 8 centers in 5 countries, with a diverse level of ambulatory dysfunction (Expanded Disability Status Scale [EDSS] <6.5), participated. Patients performed walking capacity tests and reported fatigue level at three different time points (morning, noon, afternoon) during 1 day. Walking capacity was measured with the 6-Minute Walk Test (6MWT) and the 10-m walk test performed at usual and fastest speed. Self-reported fatigue was measured by the Rochester Fatigue Diary (RFD). Subgroups with mild (EDSS 1.5–4.0, n = 53) and moderate (EDSS 4.5–6.5, n = 49) ambulatory dysfunction were formed, as changes during the day were hypothesized to depend on disability status. Results: Subgroups had different degree of ambulatory dysfunction (p < 0.001) but reported similar fatigue levels. Although RFD scores were affected by time of day with significant differences between morning and noon/afternoon (p < 0.0001), no changes in walking capacity were found in any subgroup. Additional analyses on subgroups distinguished by diurnal change in self-reported fatigue failed to reveal analogous changes in walking capacity. Conclusions: Testing of walking capacity is unaffected by time of day, despite changes in subjective fatigue.

Arm training in Multiple Sclerosis using Phantom: Clinical relevance of robotic outcome measures

Upper limb weakness due to Multiple Sclerosis has a major negative effect on the functional activities of the patient. Promising developments in the field of rehabilitation robotics may enable additional exercise. This study aims to investigate which types of robotic outcome measures are clinically relevant, in preparation of the evaluation for intervention studies.Within this context, appropriate movement tasks and tests for the haptic PHANTOM end-effector robot were designed in a virtual environment. These tasks focused on spatial accuracy, object manipulation and speed. Outcome measures were: 1) virtual movement tests, recorded by the robot to quantify motor control; 2) clinical outcome measures such as the Motricity Index, Jamar and MicroFET hand-held dynamometer to evaluate muscle strength; and the Nine Hole Peg Test, Purdue Pegboard, ARAt and TEMPA to asses upper limb function and manual dexterity.10 healthy controls performed the virtual movement tasks using the Phantom as interface. 21 MS subjects with upper limb dysfunction caused by muscle weakness were included in an interventional training study. Pearson correlations were calculated at baseline between the performance on the three virtual movement tasks and the clinical tests on impairment and activity level. The virtual movement tests discriminated between healthy controls and MS patients with hand dysfunction. In the MS patient group, no significant correlations were found between muscle strength tests and virtual movement tasks, while mainly significant correlations were found between specific functional measures (specifically ARAt and Purdue pegboard test) and virtual movement tasks.

AEROBIC INTENSITy AND pACING pATTERN DURING THE SIX-MINUTE WAlk TEST IN pATIENTS WITH MUlTIplE SClEROSIS

OBJECTIVE To examine the aerobic intensity level and pacing pattern during the 6-min walk test (6MWT) in persons with multiple sclerosis, taking into account time of day, fatigue, disability level and multiple sclerosis subtype. DESIGN Cross-sectional study. SUBJECTS/PATIENTS Eighty multiple sclerosis patients (Expanded Disability Status Scale, EDSS ≤ 6.5). METHODS Participants performed the 6MWT at 3 different time-points (morning, noon, afternoon) during 1 day. Heart rate and pacing strategy (distance covered every minute) were registered. A sub-group analysis determined the effects of fatigue, disability level and multiple sclerosis subtype. RESULTS The relative aerobic intensity was constant throughout the day (67 ± 10% of estimated maximal heart rate). In all sub-groups heart rate increased and distance walked declined after the first minute (p < 0.001). The mild EDSS sub-group showed a slightly larger increase throughout the 6MWT in heart rate development, while no differences were seen in sub-groups of fatigue and multiple sclerosis subtype. In most sub-groups walking speed was fastest in the first minute and constant during the final 4 minutes. CONCLUSION In patients with multiple sclerosis aerobic intensity is moderate during the 6MWT and unaffected by time of day. Disability may have some influence on aerobic intensity, but not on pacing strategy during the 6MWT, whereas neither fatigue nor multiple sclerosis subtype has any effect.

Spatio-temporal gait parameters change differently according to speed instructions and walking history in MS patients with different ambulatory dysfunction

BACKGROUND Different walking capacity test formats are applied, but their impact on the gait pattern in persons with MS (pwMS) has not yet been investigated according to baseline velocity performance. OBJECTIVE To assess, in pwMS with different ambulation dysfunction, the impact of speed instructions and previous walking tests (2 and 6min walking test; 2MWT and 6MWT) on spatiotemporal gait parameters. METHODS 27 participants, divided in three groups based on usual gait speed (Most Limited Community Walkers; MLCW<0.82m/s, CW>1.14m/s, LCW show intermediate values), completed the 2MWT and 6MWT. Before and after each test, they walked on the GAITRite walkway system at both usual and fastest speed. Spatio-temporal gait parameters were measured and analyzed with ANOVA. RESULTS All gait parameters in the MLCW were significantly different from other groups. In contrast to the MLCW, the LCW and CW subgroups showed greater velocity in the fastest compared to usual speed condition, associated with a significant increase in cadence and step length. After the 6MWT, small changes in cadence at usual speed and step time at fastest speed were observed in the MLCW subgroup only. No impact of the 2MWT on gait parameters was found in any group. CONCLUSIONS The ability to accelerate was dependent on the severity of ambulatory dysfunction. Prolonged walking during the 6MWT has, in contrast to the 2MWT, some impact on gait parameters in the most disabled group only.