# Group and Individual Changes in Spinal Mobility During a 12-Week Rehabilitation Program Including Swimming in Horses with Axial Musculoskeletal Lesions

## TL;DR

This study examines how swimming affects spinal mobility in horses with musculoskeletal issues during a 12-week rehabilitation program.

## Contribution

The study provides empirical data on thoracolumbar mobility changes in horses undergoing rehabilitation with swimming.

## Key findings

- Group-level analyses showed minimal changes in thoracolumbar mobility during the rehabilitation program.
- Individual horse responses varied, but not enough to alter the overall conclusion.
- Swimming did not produce uniform improvements in spinal mobility.

## Abstract

Back pain and spinal disorders often impair performance and lead to early retirement in sport horses. Swimming is commonly included in rehabilitation programs because water supports body weight, reducing limb stress while preserving cardiovascular fitness and muscle activity. However, its effect on spinal mobility remains poorly quantified. This study involved sixteen sport horses diagnosed with cervical or thoracolumbar musculoskeletal lesions who completed a 12-week rehabilitation program, including swimming sessions. Inertial sensors were placed along the spine to record weekly measurements while horses trotted in a straight line on a hard surface. Group-level analyses revealed only limited changes in back mobility across the different phases of the program. Although some horses showed individual variations, these were not consistent enough to alter the overall interpretation. Together, these findings indicate that swimming does not produce major, uniform changes in thoracolumbar mobility and underline the importance of monitoring each horse individually throughout rehabilitation, whether or not aquatic exercise is included, to guide clinical decisions and optimize recovery.

Locomotor disorders involving the spine are a major cause of impaired performance and early retirement in sport horses. Swimming is increasingly incorporated into rehabilitation protocols, but its effects on spinal biomechanics remain poorly understood. This prospective study evaluated changes in thoracolumbar mobility in sixteen sport horses diagnosed with cervical or thoracolumbar axial musculoskeletal lesions over a 12-week rehabilitation program comprising 4 weeks of land-based training followed by 8 weeks during which swimming sessions were incorporated three times per week. Weekly measurements of thoracolumbar flexion–extension range of motion (ROM) were performed during straight-line trot on a hard surface using inertial measurement units attached to the withers, T18, and tubera sacrale. Group-level analyses revealed minimal changes across training phases: in horses with thoracolumbar lesions, mean ROM decreased slightly during the second month of aquatic training (−0.1° [95% CI −0.1; 0], Cohen’s d = 0.2), whereas no significant variation was detected in horses with cervical lesions. As the study did not include a control group, these temporal changes cannot be specifically attributed to swimming and should be interpreted as descriptive rather than causal. Individual trajectories showed heterogeneous patterns, but these were not consistent enough to alter the group-level interpretation. Overall, the findings suggest that thoracolumbar mobility remains relatively stable throughout this type of rehabilitation program, highlighting the importance of individualized monitoring rather than the expectation of a uniform biomechanical response.