Extracorporeal shockwave therapy raises mechanical nociceptive threshold in horses with thoracolumbar pain.
Authors: Trager L R, Funk R A, Clapp K S, Dahlgren L A, Werre S R, Hodgson D R, Pleasant R S
Journal: Equine veterinary journal
Summary
# Extracorporeal Shockwave Therapy and Equine Thoracolumbar Pain: Clinical Implications Extracorporeal shockwave therapy (ESWT) is widely used to manage back pain in horses, yet its effects on spinal pain perception and muscle structure have received limited investigation. Trager and colleagues assessed 12 horses with thoracolumbar pain using a protocol of three ESWT treatments administered fortnightly, measuring mechanical nociceptive threshold (MNT)—a quantifiable indicator of pain sensitivity—at six spinal sites over 56 days, whilst documenting multifidus muscle cross-sectional area via ultrasound and palpation scores. The majority of horses (10/12, 83%) demonstrated improved MNT at all measurement points, with particularly marked increases in the thoracic region (64% mean improvement from baseline to day 56) compared to the lumbar region (29%), and a plateau in analgesic response by day 35 suggesting a bimodal effect pattern; notably, existing radiographic pathology did not predict treatment responsiveness, and multifidus muscle dimensions remained unchanged throughout. The analgesic benefits of ESWT appear established within this cohort, though the absence of concurrent improvements in spinal muscle cross-sectional area indicates that ESWT alone does not address muscular atrophy or weakness—practitioners should therefore consider combining shockwave therapy with targeted physiotherapy and rehabilitation programmes to achieve comprehensive functional recovery in horses with back pain.
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Practical Takeaways
- •ESWT can effectively reduce pain sensitivity in horses with thoracolumbar pain, with most horses showing improvement by day 35-45
- •The thoracic region responds better to ESWT than the lumbar region, which may inform treatment site selection
- •ESWT should be combined with physiotherapy or rehabilitation techniques to address concurrent muscle atrophy, as pain relief alone does not restore muscle mass
Key Findings
- •Mechanical nociceptive threshold increased in 83% (10/12) of horses at each time point over 56 days following ESWT
- •Average MNT increase was 64% in the thoracic region (T12-T18) and 29% in the lumbar region (L3-L5) from day 0 to 56
- •No statistically significant difference in MNT was observed between days 35-56, suggesting treatment plateau
- •Multifidus muscle cross-sectional area showed no significant change despite improved mechanical nociceptive threshold, indicating analgesia without concurrent muscle hypertrophy