Vertebra lumbalis 4
Horses typically have six lumbar vertebrae. They have broad, flat transverse processes that provide attachment for the psoas and longissimus muscles and help transfer propulsive forces from the hindquarters. Mobility is relatively limited compared with the cervical spine. The caudal lumbar vertebrae often have intertransverse joints. The lumbosacral junction (between L6 and the sacrum) is the most mobile joint in the caudal spine and a critical point for impulsion transfer. The thoracolumbar junction (around T18–L1) is a common site for kissing spines.
Origin: N/A (bone)
Insertion: N/A (bone)
Action: Transfer propulsive forces from hindquarters; support the lumbar back muscles; provide attachment for the psoas muscles (hip flexors)
Lumbar vertebrae are difficult to image with standard radiographs. Ultrasound and scintigraphy are useful. Lumbar pain presents as poor performance, reluctance to engage the hindquarters, or stiffness. Pathology at the lumbosacral junction is recognized in sport horses.
## Overview Lumbar back pain is discomfort in the loin region. Causes include muscle strain, osteoarthritis of the articular facets, overriding dorsal spinous processes (kissing spines), and rarely d
## Overview Fracture of a lumbar or thoracic transverse process usually results from direct trauma such as a kick, fall, or casting in a stall. Signs include acute localized pain, swelling, muscle gu
Reluctance to engage or collect, or pain when the back is palpated, should be evaluated. The lumbar region is not something owners manage directly, but it is important for power transfer.
## Overview Lumbar back pain is discomfort in the loin region. Causes include muscle strain, osteoarthritis of the articular facets, overriding dorsal spinous processes (kissing spines), and rarely disc disease. It is common in sport horses and produces stiffness, reluctance to engage the hindquarters, poor impulsion, and resistance to lateral work or transitions. ## Causes Overuse, poor saddle fit, conformational issues, or primary spinal pathology. ## Diagnosis Palpation, observation under saddle, diagnostic analgesia, radiographs, and sometimes scintigraphy or ultrasound. ## Treatment Anti-inflammatories, physiotherapy, saddle fit correction, and injections or surgery for specific lesions such as kissing spines. Workload modification is essential. ## Recovery and Prognosis Good for muscle strain. Chronic bony changes require ongoing management. ## Prevention Proper conditioning, correct saddle fit, and balanced training. Signs include: stiffness in the loin; reluctance to engage hindquarters; poor impulsion; difficulty with lateral work; bucking; pain on palpation
## Overview Fracture of a lumbar or thoracic transverse process usually results from direct trauma such as a kick, fall, or casting in a stall. Signs include acute localized pain, swelling, muscle guarding, and reluctance to move laterally. Ultrasound or radiographs confirm the fracture. Most heal with rest. ## Causes Direct trauma. ## Diagnosis Ultrasound or radiographs. ## Treatment Rest and anti-inflammatories. Surgery is rarely needed. ## Recovery and Prognosis Good. ## Prevention Trauma avoidance. Signs include: acute localized pain; swelling; muscle guarding; reluctance to move laterally; confirmed on ultrasound or radiographs
Lumbar vertebrae are difficult to image with standard radiographs. Ultrasound and scintigraphy are useful. Lumbar pain presents as poor performance, reluctance to engage the hindquarters, or stiffness. Pathology at the lumbosacral junction is recognized in sport horses.
Reluctance to engage or collect, or pain when the back is palpated, should be evaluated. The lumbar region is not something owners manage directly, but it is important for power transfer.
See the Lumbar Vertebra (L4) on our interactive 3D horse model. Open 3D Model