The effect of induced forelimb lameness on thoracolumbar kinematics during treadmill locomotion.
Authors: Gómez Alvarez C B, Wennerstrand J, Bobbert M F, Lamers L, Johnston C, Back W, van Weeren P R
Journal: Equine veterinary journal
Summary
# Editorial Summary When horses develop forelimb lameness, compensatory changes ripple through their entire kinetic chain, yet quantifying these spinal adaptations has remained elusive until now. Álvarez and colleagues used treadmill-based motion capture and ground reaction force analysis to measure thoracolumbar kinematics in six riding horses before and after inducing reversible grade 2 forelimb lameness, examining both walk and trot. At trot, lame horses unloaded the affected limb by 11.5% whilst simultaneously increasing overall spinal flexion-extension range by 3.3 degrees, with marked changes in vertebral motion patterns: the thoracolumbar region extended significantly during the lame diagonal's stance phase (0.7–0.8 degrees across multiple segments), and the cranial thoracic spine laterally bent up to 1.3 degrees toward the lame side. Walk demonstrated minimal kinetic changes despite lameness, suggesting the gait's inherent stability masks compensatory movement. These findings carry important implications for practitioners: whilst acute Grade 2 lameness triggers immediate and measurable spinal compensation at faster gaits, the chronic adoption of these altered movement patterns may predispose horses to secondary back dysfunction—emphasising the need for prompt diagnosis and rehabilitation to prevent long-term musculoskeletal consequences.
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Practical Takeaways
- •Subtle forelimb lameness produces measurable compensatory changes in spinal kinematics, particularly at trot, suggesting back dysfunction may develop secondary to limb lameness
- •Horses demonstrate immediate biomechanical adaptations including lateral bending toward the lame side—consider evaluating thoracolumbar mobility and symmetry when addressing forelimb lameness
- •The increased range of motion at trot (rather than walk) suggests lameness effects worsen at faster gaits; chronic lameness may lead to progressive back dysfunction requiring multimodal management
Key Findings
- •Horses unloaded the painful forelimb by 11.5% at trot but not significantly at walk
- •Overall flexion-extension range of back motion decreased by 0.2° at walk and increased by 3.3° at trot with induced lameness
- •Lameness caused lateral bending of the cranial thoracic vertebral column towards the lame side (1.3° at T10, 0.9° at T13) during lame diagonal stance
- •Vertebral angular motion patterns changed significantly at trot with increased flexion at T10 and increased extension throughout thoracolumbar area during lame diagonal stance