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Authors: Golovin M.A., Skrebenkov E.A., Koltsov A.A.
Institutions: Federal State Budgetary Institution «Federal Scientific Center of Rehabilitation of the Disabled named after G.A. Albrecht» of the Ministry of Labour and Social Protection of the Russian Federation.
Year: 2018
Publication: Rehabilitation – XXI century: traditions and innovations: a collection of articles II National Congress with international participation, St. Petersburg, 12-13 September 2018 / Ministry of Labor of Russia.
Abstract:
A number of diseases, namely: atrophy, paralysis, including neuromuscular deformities of the spine and spinal-muscular atrophy, ankylosing spondylitis, impose special medical and technical requirements to the design and appointment of wheelchairs. An important feature of their operation is the stabilization of the wheelchair operator’s position, and, in particular, his head. Stabilization in the wheelchair is necessary to ensure ergonomic control. A lack of stabilization leads to compensatory movements by the operator. In order to stabilize the operator, surgical techniques have been developed, the information about their application is absent. At present, there is a small number of IRKs with stabilization of the operator’s position when moving on an inclined surface.

The purpose of the study:
To register compensatory movements in the cervical and thoracic lumbar spine when entering and leaving the ramp.

Materials and methods:

People without musculoskeletal system diseases took part in the study: 4 men (30±5 y/o) and 1 girl (23 y/o); and patients with MDF diseases: children (8±4 y/o), man (32 y/o) and woman (66 y/o).

For the study a ramp with a constant angle of slope of 13 degrees was used, the entry of which starts steplessly from the floor level. The wheelchair base is 350 mm, wheel diameter: 8″ at the front and 12″ at the back; the backrest is vertical. Measurements were made using the H.MotionLab complex. This allowed a non-contact motion analysis. The study was conducted with a combination of natural and artificial lighting. Patients were wearing pants and long-sleeved clothing. The feet were placed wide on the leg supports to ensure free distance between knees. This condition is necessary for a correct body schema in H.MotionLab software. The research methodology included the following main steps. The ramp was installed in front of the Habilect complex, with a large ramp height at a distance of 1 m from the module. The user took a comfortable position in the wheelchair, the forearms were placed on armrests along the IRK. The assistant rolled the subject in a wheelchair on a ramp at a speed of 0.4 m/s until the rear wheels entered the ramp. After that, the assistant provided descent backwards at a speed of 0.4 m/s. Then the test was repeated at a speed of 0.8 m/s. Analysis of the obtained data was performed in the H.MotionLab Kinematics module. Trajectories of movement in the sagittal plane of 4 points of the body were assessed: the center of the head, interclavicular fossa, solar plexus, center of the pelvis. The moment of compensatory movements was clearly defined for all subjects when entering the ramp. The time of compensatory movements occurrence at the entrance was 1.1±0.3 seconds from the moment of entry into the ramp in the control group, 1.9±0.5 – in patients. At the departure: 1.2±0.8 in the control group, 1.6±0.6 in the disabled. The amplitude of compensatory movements in the neck and chest department in patients was 2 degrees in the control group and 6,5±1,5 degrees in the disabled group. The amplitude of compensatory movements in the chest and lumbar region was absent, the angle of inclination of the upper torso was 3 degrees in all patients.

Results and discussions:
Objective data were obtained on movements in the cervico-chest and chest-lumbar spine in the sagittal plane when entering and leaving the ramp. Further investigation will focus on determining the sagittal angle of the wheelchairin the sagittal plane at which compensatory movements occur at different ramp angles. The data obtained can be used in the design of wheelchairs with a system of seat stabilization, namely, the formation of technical requirements for the sensitivity and speed of the mechanism of adaptation of the position.