Effect of local analgesia on movement of the equine back

Abstract

Summary Reasons for performing study: Diagnostic infiltration of local anaesthetic solution is commonly used in cases of equine back pain. Evaluation is subjective and it is not known how local analgesia of the back affects horses without clinical signs of back pain. Objectives: To evaluate the effect of infiltration of local anaesthetics on the movement of the back in horses without clinical signs of back pain, and to evaluate the usefulness of kinematic studies as an objective and quantitative tool in evaluating local analgesia in clinical practice. Methods: The kinematics of the back in 10 clinically sound horses were measured on 2 occasions at walk and trot before and after injections with mepivacaine and sodium chloride around the interspinous spaces between T16 and L2. The kinematics were compared between the 2 occasions before injections and before and after each injection. Results: The range of motion (ROM) for dorsoventral flexion‐extension (FE) of the back was increased significantly in all measured segments other than T10 at walk, as was lateral bending (LB) at T10, L3 and L5 after injection of mepivacaine. For lateral excursion (LE), total movement increased at all measured segments. At trot the only affected segment was L3, where the injection with mepivacaine decreased the ROM for FE. After injection of sodium chloride the ROM for FE increased at T13 and T17 at walk. Lateral bending and LE were not affected at walk. At trot, LB increased at L3 and L5. Conclusions and potential relevance: Diagnostic infiltration of local anaesthetic solution affects the function of the back in clinically sound horses, which must be considered when interpreting the use of this clinical aid in assessing clinical cases of back dysfunction. Kinematics can qualitatively and quantitatively evaluate the effect of local analgesia of the back.

Association of a Subjective Muscle Score With Increased Angles of Flexion During Sitting Trot in Dressage Horses

“…This has been used extensively to determine back kinematics in ridden and unridden subjects at various gaits [27][28][29][30][31][32][33][34][35][36][37][38][39] and does not need laboratory conditions. The aim of the study was to investigate the relationship between subjective grading of muscle development (the "muscle score") and back kinematics.…”

Clinical progress in the diagnosis of thoracolumbar problems in horses

“…However, Holm et al . () found that local infiltration of an anaesthetic solution in and around T16 to L2 results in a change in the function of the back in asymptomatic horses. Horses without perceived back pain showed increases in dorsoventral flexibility as well as lateral bending following infusion of mepivicaine along the spine.…”

Gestion des thoraco-lombalgies chez le cheval

“…Une augmentation de la perception de la douleur avec le temps et la répétition des stimulus nociceptifs (wind up) (Rang et al 1995) et une adaptation des mouvements à la douleur chronique (Wennerstrand et al 2004 ;Bromily, 2009) pourraient empê-cher une normalisation immédiate des mouvements après l'anesthésie. Par ailleurs, l'aanesthésie semble affecter le mouvement du dos chez des animaux sains (Holm et al 2006).…”