Kayak Ergometer Training in Individuals With Spinal Cord Injury

Spinal Cord Injury (SCI) is an alteration of the spinal cord that modifies not only muscular strength and sensitivity, but that also generates a change in all of the systems of the organism. At the worldwide level, an incidence is calculated of between 13.1 and 52.2 per one million inhabitants.

Damage to the ascending and descending tracts of the spinal cord consequently gives rise to an alteration in the postural control system. It is known that effective postural control is of utmost importance forstanding and walking, as well as for providing support for voluntary movements. Alterations in posture depend on the grade and level of the injury; thus, persons with complete, thoracic, or cervical lesions have poor trunk control. Due to the latter, they are limited in many of the movements necessary for carrying out daily life activities (DALYS) Therefore, part of the objectives of rehabilitation in individuals with an SCI comprises improvement in trunk control.

On the other hand, patients with SCI tend to engage in a sedentary lifestyle that, added to the alterations in the autonomic nervous system proper to the lesion, exposes individuals with a SCI to a greater risk of developing chronic-degenerative conditions, such as metabolic syndrome and cardiovascular diseases, which are, at present, the main cause of death in these persons.

Thus, after the immediate rehabilitation, it is necessary to maintain and improve the functional capacity obtained during this process. Therefore, it is important to find training activities to challenge stabilization of the upper part of the body and sitting equilibrium without giving rise to symptoms caused by overuse.

Kayak training appears to comply with these criteria, in that it implicates the greater part of the upper musculature, presents high metabolic demands, and imposes strict requirements for the balance control system, due to continuous compensation of the disturbances of the upper part of the body caused by movement on the apparatus. It was previously demonstrated that open-sea training in kayaks could be implemented in a group of individuals in paraplegic condition and that this is accompanied by improvements in strength and equilibrium in sedestatIon.

Due to the difficulty in controlling and adjusting the time and challenge level of the equilibrium experienced by participants at sub-acute stages, it is necessary to utilize a kayak ergometer, in such a way that the demand for equilibrium can be adjusted individually and for this to increase progressively as the treatment advances. In this respect, Bjerkefors and Thorstensson demonstrated that kayak ergometer training in a group of persons with SCI is accompanied by improvement in shoulder muscular strength and in various functional wheelchair tests that demand trunk stabilization and balance control.

These studies achieved demonstrating the positive effect of kayak training in patients with SCI; however, in these studies, small populations were included (10 and 12 individuals), with chronic-stage lesions, and the effects on trunk control were not evaluated by means of a validated scale in this population, nor were the training's effects on cardiovascular function and functional independence.

To date, the effect of kayak ergometer training has not, to our knowledge, been studied in individuals with SCI in terms of trunk control with tools validated for persons with SCI, regarding the cardiovascular condition, functional independence, and quality of life, thus engendering the need to conduct this present study.

HYPOTHESIS

Kayak ergometer training will improve functional independence, trunk control, and cardiovascular condition in individuals with SCI.

The effect of training with the kayak ergometer on functional independence, trunk control, and the cardiovascular condition in individuals with SCI will be greater than that of conventional trunk-control training.

GENERAL OBJECTIVE

To determine the effect of kayak ergometer training in patients with SCI in functionality, trunk control, cardiovascular condition, and quality of life.

SPECIFIC OBJECTIVES

• Establish the validity, reliability, error, and sensitivity of the measurement instrumented of trunk control in subjects with SCI.
• Evaluate the existence of floor/ceiling effects in the instrumented assessment of trunk control.
• Develop computerized tools for evaluation of trunk control that are easily applicable in daily clinical practice, with low-cost, practical, and simple technology for improving the exactness and reliability of the observational analysis, for rehabilitation centers that are not equipped with a movement-analysis laboratory, with sufficient information for evaluating the trunk control of the individual with SCI.
• Proposal of a pilot program of trunk control rehabilitation in persons with SCI.
• Broadcast preliminary results at a national scientific meeting.
• Form human resources with knowledge of neurological rehabilitation, movement analysis, and biomedical engineering.
• Foster multidisciplinary cooperation.

MATERIALS AND METHODS

Study type. Randomized controlled clinical trial blinded to the evaluator and to the person performing the data analysis.

Description of the work universe. Patients of out-patient consultations and hospitalization of the SCI Service of the National Institute of Rehabilitation), with a diagnosis of SCI of any etiology, with a neurological level of under C8, with a SCI of 3 months of evolution.

Definition of the control group Group A. Control group, management with conventional therapy for improvement of trunk control (proprioceptive neurofacilitation exercises focused on trunk control21) of 20 minutes five times weekly during 6 weeks.

Sample size We utilized the Epidat ver. 4 statistical software program to calculate sample size. For 80% study power and an alpha error probability of less than 0.05, and considering the work of Grigorenko and collaborators18 we found a frontal displacement speed difference of the Center of Pressure (CoP) of 0.1m/s with a Standard Deviation (SD) of 0.05 m/s between the experimental and the control group. Therefore, seven patients per group were required. Considering a possible loss of 20%, we will recruit nine patients per group.

Description of the study variables, units of measure, and measuring scales

Clinical and demographic variables

• SCI severity: According to American Spinal Injury Association, with International standards for neurological classification of spinal cord injury modifications: complete, B: incomplete, preservation of only the sensitive function, C: incomplete, voluntary anal contraction or more than half of key muscles in <3, D: incomplete, more than half of the key muscles in >3, E: total recuperation A, B, C, D, E
• Neurological level: More caudal segment of the SC with normal function
• Time of evolution of the SCI:Time in days elapsed from when the SCI was produced until time of application of the questionnaire
• Age:Years elapsed from date of birth to time of questionnaire application

Proposed statistical analysis

The investigators will utilize the Statistical Package for the Social Sciences ver. 17 statistical software program. The investigators will perform descriptive statistics with central-tendency measurements for quantitative variables and with proportions for qualitative variables. To determine differences between groups, analysis of covariance will be carried out. Results that are statistically significant with a p of <0.05 will be considered.