Thoracolumbar kinematics of horses submitted to dynamic mobilization associated with neuroreflexive exercises

Abstract

Dynamic mobilization is commonly used in exercise protocols for the management of spinal pain, because it restores the range of motion of flexion, improving the function of this segment in humans. However, the exact mechanism of action for the improvement in flexion of the thoracolumbar region of horses is unknown, and besides muscle hypertrophy and symmetry, the influence of reflex muscle relaxation in the gain of flexion range of motion is also hypothesized. Thus, additional evaluation of neuroreflex stimuli associated with dynamic mobilization exercises is justified for a better understanding of spinal flexibility. The objective will be to study the kinematic effects of dynamic mobilization exercises associated with neuro-reflexive stimuli over 120 days in asymptomatic fundamental horsemanship horses. Twelve horses of undefined breed will be used, which will be monitored before (day 0) and at the end of the experimental period (day 120). The treatments will consist of four experimental groups: one group will be composed of horses that did not undergo dynamic riding and no reflex exercises, called control (CON); the second group will be composed of horses submitted only to dynamic mobilization (MOB); the third group will be composed of horses that underwent dynamic riding and reflex exercises on the sternum (MOB_STE); and the last group will be composed of horses that underwent reflex exercises on the pelvis (MOB_PEL). The horses will be distributed in an entirely randomized design, with three repetitions per treatment. The dynamic mobilization and neuro-reflexive exercises will be performed in the horses three times a week for four months. The experimental horses will be submitted to a series of dynamic mobilization exercises consisting of three longitudinal cervical flexions (head on chest, head between the carpals, head between hooves), one cervical extension and three lateral cervical flexions (head on shoulder, patella and hock), right and left sides, totaling ten mobilizations. The horses will also perform neuro-reflexive exercises, as designated by the experimental treatments, sternal raising (STE) or pelvic flexion (PEL). Static kinematic variables will be evaluated by means of hemispherical markers such as depth (cm), angle (°), difference in depth and angle for each vertebral level analyzed (T10, T13, T17, L1 and L3), as well as total range of motion for depth and angle, in which this parameter will express the entire thoracolumbar motion. Hemispherical markers will be applied to seven dorsal spinous processes. The dorsal markers will be placed at the highest point of the withers, T10, T13, T17, L1, L3 indicated by palpation of the ribs, at the midpoint between the sacral tuberosities (TS), located by palpation of the TS, signaling the spinous process of the first sacral vertebra. Photographic images of the horses will be taken using an iPad mini (Apple iPad mini model A1432, Apple, Cupertino, CA, USA). The images taken will be analyzed with the help of Corel Draw software (version X7). Kinematic data of the horses' spine will be presented as mean, with standard deviation (±d.p.) as a measure of dispersion. Variables will be evaluated for normality of distribution using the Kolmogorov-Smirnov test. For data with normal distribution the analyses will be conducted using ANOVA (SAS, 2000) and comparison of means by Tukey's test. In case the data is not normally distributed, the Wilcoxon test will be used. Statistical tests will use 5% probability. (AU)