Robot-assisted Gait Training in Multiple Sclerosis Subjects

The Effects of Robot-assisted Gait Training on Locomotor Function and Motor Unit Firing in Multiple Sclerosis Subjects With Severe Gait Impairments. A Randomized Control Trial

Aims of the study: This is a randomized-controlled trial to test the effects of robot-assisted gait training on locomotor function and motor unit firing rate in multiple sclerosis subjects with severe gait impairments. The control group will be treat with conventional physical therapy. Subjects and methods: 60 multiple sclerosis patients will be recruited in two outpatient rehabilitation clinics. Informed consent will be obtained. Participants will be randomized to Robot-assisted gait training (experimental group) or conventional therapy (control group) through a randomization stratification approach, according to a block randomization of 4. The experimental group will receive 12 robot-assisted gait training sessions over 6 weeks (2 sessions/week). The control group will receive 12 conventional therapy sessions over 6 weeks (2 sessions/week), that will focus on gait training. Primary outcome measures will be both neurophysiological measures (motor unit firing rate characteristics) and clinical test for gait speed (10m walking test). Secondary outcome measures will include: clinical tests of walking endurance (six minute walking test), balance (Berg Balance Test) and mobility (Up and Go Test). Clinical assessment of lower-extremities spasticity (Modified Ashworth Scale), motor fatigue (Fatigue Severity Scale), depression (PHQ-9) and quality of life (SF-36) will be monitored. Subject acceptance and confidence in the treatments will be track with a Visual Analog Scale. Outcome measures will be assessed the week prior to treatment initiation (T0), after 6 sessions (T1), the week after the end of treatment (T2) and at 3 months follow-up (T3) to evaluate treatments retention, by a clinician blinded to the treatment.

Subjects will wear a harness attached to a system to provide body weight support and they will walk on a treadmill with the help of a robotic-driven gait orthosis. The legs are guided according to a physiological gait pattern. The torque of the knee and hip drives can be adjusted from 100% to 0% for one or both legs. The speed of the treadmill can be adjusted from 0 km/h to approximately 3 km/h and body weight support from 0% to 100%. Training sessions will last for an hour with 30 minutes of real walking time, because subject set-up in the device take approximately 30 minutes.

Training sessions will focus on locomotor function improvements. Subjects will receive 45 minutes of individual conventional physiotherapy for session. During the first 5-10 minutes the subjects will perform lower-limb and core stretching exercises to increase muscles flexibility; then they'll deal with lower-limb muscles strengthening exercises tailored on their baseline characteristics (10 minutes). After that they will be trained on walking abilities (like walking at different speeds, rapid changes directions) for 30 minutes with or without assistive aids.

It will be performed through the analysis of superficial EMG signals during isometric knee extension.

Inclusion Criteria: males and females, community dwelling, age 18 or older diagnosis of multiple sclerosis in a stable phase, with relapses > 6 months prior to study enrollment moderate to severe gait impairments referred to Expanded Disability Status Scale (EDSS) between 6 and 7 Exclusion Criteria: neurologic conditions in addition to multiple sclerosis that may affect motor function medical conditions likely to interfere with the ability to safely complete the study impaired cognitive functioning: Mini Mental Status Examination < 24 severe lower-extremities spasticity or contractures that may limit range of motion(Ashworth score >4 for hip, knee or ankle flexors/extensors