In man, vibration therapy has been shown to be of benefit both in a clinical and sporting context, although in its infancy in the horse, similar benefits have been reported. To evaluate the immediate effect that cycloidal vibration therapy has on thoracolumbar range of motion and thoracolumbar muscular dimensions, 30 nonlame horses (mean ± SD age 12 ± 8.77 years, mean ± SD height 1.65 ± 0.94 m) were split into two groups: treatment group and placebo group. Horses were equipped with eight inertial sensors. A treatment group received a 20-minute cycloidal vibration therapy and a placebo group received no treatment. Differences in thoracolumbar epaxial musculature dimensions were obtained pre and post for both groups. A paired t test was carried out to determine differences in movement and thoracolumbar musculature dimensions (P ≤ .05) for both groups. In the treatment group, an increase in range of motion of the wither in a vertical direction (Pre 69:00 ± 8.77 mm, Post 70.84 ± 8.79 mm, P = .04) and the 13th thoracic vertebral segment in a mediolateral direction (Pre 26.45 ± 4.29 mm, Post 29.27 ± 5.29 mm, P = .01) was found. Thoracolumbar musculature dimensions increased at T10 (3 cm), (Pre 20.90 ± 3.42 cm, Post 21.72 ± 3.30 cm, P = .02) and T13 (3 cm), (Pre 27.01 ± 5.11 cm Post 28.23 ± 5.56 cm, P = .02). No significant differences (P≥0.13) were found for any inertial measurement units-derived movement parameter and thoracolumbar musculature dimensions for those horses in the placebo group. Cycloidal vibration therapy applied in the region of the thoracic spine and hind quarters is associated with altered kinematics of the thoracolumbar.