ABSTRACT
Objective To observe the efficacy of underwater partial body-weight-supported treadmill training in repairing spinal cord injury (SCI) and its relationship with spinal nerve plasticity. Methods A total of 40 Sprague-Dawley rats were randomly divided into five groups: a sham model group, a model control group, an underwater training group, a partial body-weight-supported treadmill training (PBWSTT) group and an underwater PBWSTT group. A rat model of SCI was induced by contusion of the T10 segment with a Multicenter Animal Spinal Cord Injury Study (MASCIS) impactor. One week post-operation, different rehabilitation strategies, such as free exercise in water, BWSTT and underwater PBWSTT, were administered to the rats in the underwater training groups for 8 weeks.Those in the sham model group and model control group were given no training. The Basso, Beattie and Bresnahan (BBB) locomotor rating scale and a climbing test were used to evaluate the recovery of hindlimb locomotor function.The expression of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in the spinal cords was detected with immunohistochemical methods. Results Nine weeks post-operation, hindlimb locomotor function had improved significantly more in the underwater PBWSTT group than in underwater training group or the BWSTT group.The expression of BDNF in the 3 training groups was significantly higher than in the model control group, though there was no significant difference among the 3 training groups. The expression of NT-3 in the underwater PBWSTT group increased more significantly than in the BWSTT group, however there was no significant difference between the underwater PBWSTT group and the underwater training group. Conclusion Underwater PBWSTT can promote the recovery of hindlimb locomotor function in rats after SCI, probably through increasing the expression of BDNF and NT-3 and thus promoting neural plasticity in the spinal cord.
ABSTRACT
Objective To survey cervical myoelectric signals during craniocervical flexion, neutral and extension postures, and to explore the evidence that proper head position can alleviate cervical muscle fatigue in a lateral recumbent position. Methods Surface electromyography (sEMG) signals were detected from the sternocleidomastoid, upper trapezius and erector spinae muscles of 30 young subjects bilaterally during craniocervical flexion,neutral and extension postures in the left lateral recumbent position. The integrated trace area (IEMG) and median frequency (MF) were estimated. Results The average IEMG of the sternocleidomastoid muscles was significantly lower in flexion than in extension bilaterally. The average IEMG of the erector spinae muscles was lower in extension than in flexion bilaterally, and the difference was again significant. The IEMGs of the upper trapezius muscle showed no significant difference on average in the three postures bilaterally. There was no significant MF difference in any of the muscles. Conclusions The muscles in the cervical back were less activated during craniocervical extension in a lateral recumbent position. A little cranicocervical extension is optimal while resting in a lateral recumbent position.