Myosuit in Incomplete Spinal Cord Injury

Rationale: People with incomplete spinal cord injury (iSCI) show often impairments and limitations related to gait, which negatively affects daily life gait performance (i.e. ambulation in home and community setting) and quality of life. As a consequence of limited gait capacity, these people are likely to develop a sedentary lifestyle resulting in a vicious circle, causing a further decline in gait capacity and daily life gait performance. One of the potential options to improve gait is the use of assistive technology, such as exoskeletons or exosuits. People with iSCI have voluntary control of the leg muscles may benefit more from light-weighted exosuits which provide assistance during walking. Recently, a lower extremity soft exosuit, the Myosuit (MyoSwiss AG), has been introduced. In a small sample study, participants showed an increased gait speed when using the Myosuit compared to their baseline gait speed. Moreover, only a small number of training sessions was required to use the Myosuit. Hence, the Myosuit seems to have a high potential to increase gait capacity and daily life gait performance in people with residual gait capacity.

Objective: The study consists of two parts, randomized controlled trial (RCT) and experimental design. In the RCT, the primary objective is to test the efficacy of the Myosuit for increasing daily life gait performance in the home and community setting in people with iSCI. Secondary, the efficacy of the Myosuit program on gait capacity and its cost-utility will be investigated. Finally, the usability of the Myosuit for use in home and community setting will be evaluated. In the experimental design, we will investigate differences in gait capacity with and without wearing the Myosuit in people with iSCI, by conducting clinical tests. Secondary, differences in gait capacity measured on an instrumented treadmill with and without wearing the Myosuit will be examined.

Study design: RCT and within subject experiment.

Study population: Thirty-four people with chronic iSCI (>6 months after injury) and reduced gait capacity due to reduced knee and/or hip strength (MRC<5) will be recruited for this study. People with iSCI will be included when having an injury level of C or D on the American Spinal Injury Association Impairment Scale. In addition, participants need to have sufficient hand function to don and doff the Myosuit or they need a caregiver who is available to help the participant to use the Myosuit at home. Patients who have another (neurological) disease which can influence motor performance and/or patients who have small wounds, which can be worsened by wearing the Myosuit will be excluded. For the second objective of the experimental design, only people who are be able to walk consecutively for two minutes on a treadmill without any assistive device and without using the handrails will be included.

Intervention: RCT: The intervention group will perform training sessions with the Myosuit at the Sint Maartenskliniek. Thereafter, they will receive the Myosuit at their disposal at home and a recommendation for physical activity for six weeks. The control group will receive a program of conventional physiotherapy at the Sint Maartenskliniek. Thereafter, they receive a recommendation for physical activity for at home for six weeks.

Experimental design: Participants perform clinical tests and measurements on an instrumented treadmill with and without the Myosuit.

Measurements intervention and control group:

• Baseline: Week 1 (T0)
• After clinical training program at the Sint Maartenskliniek: Week 5 (T1)
• During 6 weeks home period: Week 6, 8, 11 (T2, T3, T4)
• After the 6 weeks home period: Week 12 (T5)

Additional measurements for the control group who receive the Myosuit intervention after the conventional program:

• After clinical training program at the Sint Maartenskliniek: Week 16 (T6)
• During 6 weeks home period: Week 17, 19, 22 (T7, T8, T9)
• After the 6 weeks home period: Week 23 (T10)

Inclusion criteria

• People with a stable chronic iSCI (>6 months after injury).
• Having an injury level of C or D on the American Spinal Injury Association Impairment Scale.
• Age ≥ 18 years.
• Need to have sufficient hand function and standing balance to don and doff the Myosuit or they need a caregiver who is available to help the participant to use the Myosuit at home.
• Having reduced gait capacity due to reduced knee and/or hip strength (MRC=<4).
• Must be able to stand up from a chair without deviating to the left or right side for more than 45 degrees during the movement.
• Can walk for 10 meter without the assistance of another person but can be assisted by assistive devices except knee orthoses.
• People aim to improve walking distance, walking speed or gait capacity.
• Sufficient postural control to walk independently (i.e. without assistance of a person, assistive devices are allowed).
• For the second objective of part B of this study, only people who are be able to walk consecutively for two minutes on a treadmill without any assistive device and without using the handrails will be included

Exclusion criteria

• Have another (neurological) disease which can influence motor performance.
• Have wounds which can be worsened by wearing the Myosuit will be excluded.
• Taller than 195 and smaller than 150 cm.
• Body weight of more than 110 kg or less than 45 kg.
• Pregnancy.
• Insufficient mastery of the Dutch language
• Psychiatric background.
• Flexion contracture in knee or hip in excess of 10 degrees.
• Knee varus malposition in excess of 10 degrees or knee valgus malposition in excess of 10 degrees.
• Oncological spinal cord injury.
• Unsuitable for participation according to the rehabilitation physician or researcher.