The effect of induced hindlimb lameness on thoracolumbar kinematics during treadmill locomotion
Authors: ALVAREZ C. B. GOMEZ, BOBBERT M. F., LAMERS L., JOHNSTON C., BACK W., van WEEREN P. R.
Journal: Equine Veterinary Journal
Summary
# Editorial Summary Whilst clinicians recognise that hindlimb lameness affects spinal motion, quantitative data describing these relationships remain sparse. Gomez and colleagues used kinematic analysis with reflective markers to track thoracolumbar movement in six riding horses during walk and trot before and after inducing subtle lameness (grade 2 AAEP scale) via sole pressure on the left hindlimb; ground reaction forces were calculated from marker positions to assess limb loading changes. Despite inconsistent unloading of the lame limb across the cohort, statistically significant alterations in back kinematics emerged: flexion-extension range of motion increased at walk (particularly in thoracic segments) alongside increased pelvic axial rotation, whilst at trot only the lumbosacral segment (L3–L5–S3) showed decreased range of motion; during stance of the lame limb, the mid-thoracic segment (T6–T10–T13) demonstrated increased flexion and the neck lowered at both gaits. The findings underscore that even subtle lameness triggers measurable spinal compensations characterised by hyperextension and increased thoracolumbar mobility, whilst paradoxically reducing lumbosacral motion—a pattern with significant implications for practitioners, as chronic low-grade lameness may precipitate cumulative back dysfunction and warrants earlier intervention before secondary spinal pathology develops.
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Practical Takeaways
- •Even subtle hindlimb lameness not readily visible in traditional lameness exams can trigger compensatory changes in spinal motion that may lead to chronic back problems—early detection and treatment of subtle lameness is important for back health
- •When investigating back dysfunction or poor performance, always assess for subtle hindlimb lameness as a potential underlying cause, as the connection between limb and spinal function is intricate
- •Horses may not show obvious unloading of a lame limb (only 4 of 6 did) despite kinematic evidence of lameness, so rely on movement analysis and clinical observation rather than assuming weight-bearing alone indicates soundness
Key Findings
- •Subtle hindlimb lameness (grade 2/5 AAEP) induced statistically significant changes in thoracolumbar kinematics despite minimal limb unloading in most horses
- •Flexion-extension range of motion increased at walk in thoracic segments, with increased axial rotation of the pelvis
- •During stance phase of the lame limb, segment T6-T10-T13 showed increased flexion and neck lowering at both gaits
- •Chronic subtle lameness may induce compensatory back dysfunction through altered thoracolumbar motion patterns