Effects of a 6‐week dynamic mobilisation exercise program on thoracolumbosacral kinematics in sports horses

Background: Dynamic mobilisation exercises (DME) are prescribed to support locomotor function, but knowledge on their longitudinal effect on thoracolumbosacral (TLS) spinal kinematics is limited. Objectives: To evaluate the effect of a six-week DME program on TLS kinematics during standing reflexes, walking and trotting. Methods: Thirty-nine work matched horses were split into two groups; DME and controls. Horses straight-line trot was assessed at week 0 and week 6 by a veterinarian (≤1/5AAEP) and physiotherapist who assessed muscle hypertonicity and assigned palpation scores. Surface mounted inertial measurement units and reflective markers (19mm) were positioned at head, Thoracic (T)6, T10, T13, T18, Lumbar (L)3, L5 between left and right tuber sacrale (TS) and left and right tuber coxae. Sternal and croup reflexes were quantified using optical motion capture (240Hz) and straight-line walking and trotting kinematics using IMUs (100Hz). Mixed models assessed relationships between vertical displacement during reflexes and differential flexion-extension (FE)/lateral bending (LB)/axial rotation range of motion (ROM) at walk, trot and predictors: week, group, movement and covariates: asymmetry values and palpation grades (P≤0.05). Results: No significant changes in vertical displacement in the reflexes or FE ROM during walk and trot were observed in the DME group (P>0.05). Vertical displacement in the croup reflex at T13, FE ROM at T13–T18 during walk, FE ROM at T18–L3 and LB at T6–T13 during trotting decreased at week 6 in both groups (P<0.02). Head and pelvic asymmetry values and palpation grade had significant relationships with kinematics during reflexes and walking and trotting (P<0.05). Main limitations: Horses only had straight line gait assessment. Conclusions: DME had limited impact on TLS kinematics over six weeks; however, the findings highlight the influence of gait asymmetry and palpation grades, underscoring the importance of addressing these factors alongside exercise prescription for optimal functional outcomes.