Postural control in individuals with spinal cord injury: Training, functional performance, and mechanisms

• BACKGROUND AND AIM: Postural control in sitting is essential for people with spinal cord injury (SCI). Studies indicate that impaired postural control is related to decreased propulsion efficiency, respiratory dysfunction and development of pressure sores. Despite this, there is limited knowledge on the best methods to rehabilitate postural control in people with SCI and if and by what mechanism persons with high-thoracic SCI may improve their postural control. Thus, our aims were to 1) determine the efficacy of targeted rehabilitation towards postural control in people with SCI, and 2) investigate the neural mechanisms behind any observed improvements. METHODS: Persons with SCI completed 30 sessions over 10 weeks of a) seated double poling ergometer (SDP) training (n=13) or b) kayak ergometer (KE) training (n=10). Before and after functional tests were performed and included: sit-and-reach tests, propelling 15m on a level surface and propelling 50m up a 3º incline. Additionally, subjects sat in their wheelchair while support-surface translations were presented (KE) or performed isometric maximal voluntary contractions in a dynamometer during trunk flexion and extension (SDP). To investigate neural mechanisms of postural control improvement, electromyographic (EMG) responses in the ventral postural muscles to maximal voluntary contractions and transcranial magnetic stimulation (TMS) were assessed in 5 individuals with motor complete SCI above T6. RESULTS: Postural stability was improved after KE and SDP training demonstrated by smaller rotational and linear displacements of the trunk during support surface translations (KE) and improved postural muscle strength (SDP). There were also significant improvements in propelling tasks and in the sit-and-reach tasks, both in the sagittal plane (SDP) as well as in lateral directions (KE). All persons with motor complete SCI above T6 (n=5) were able to elicit task specific EMG activity in the ventral postural muscles during maximal voluntary contractions despite their clinical classification. Motor evoked potentials were also recorded in each individual´s ventral postural muscles in response to TMS, confirming corticospinal pathway preservation.  CONCLUSIONS: Postural control, upright sitting, and functional performance in daily life activities can be improved in people with high-thoracic SCI during regular exercising, such as kayaking and seated double poling ergometer training. The neural mechanism behind the improvement is in part due to partial preservation of the corticospinal pathways to the postural muscles as confirmed by the use EMG and TMS. 

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Idrottsvetenskap (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Sport and Fitness Sciences (hsv//eng)

Keyword

postural control

balance

spinal cord injury

kayak

training

Medicin/Teknik

Medicine/Technology

Publication and Content Type

ref (subject category)

kon (subject category)