Does your horse have pain in the hip/sacroiliac (SI) region? I asked myself this very question a few weeks ago as I watched Harvey on the end of a lunge line. He was definitely gimpy and reluctant to trot out. He does have hock issues, but to my layman's eye, it looked like there was something wrong "higher up." A few weeks off did him wonders, but I researched hip/SI pain while he rested. The article Clinical Features of Pain Associated with the Sacroiliac Joint Region: A European Perspective offers some indicators for pain in the SI region. Note that as you get further down the list the symptoms get more vague.
Disclaimer: In the first version of this article, I lumped the hip and the sacroiliac together, mostly because "sacroiliac" is not an everyday term. As a reader noted in comments, the hip and the sacroiliac regions are different. The sacroiliac region is depicted to the right. The hip joint is further down and attaches the femur to the pelvis. An illustration of the horse skeleton should clarify this a bit.
A study of horses who were diagnosed with sacroiliac pain showed these behaviors:
- Horses may stand with their thoracolumbar region (between sections 3 and 4 in picture above left) a little roached.
- Horse may shift weight constantly between the two hindlimbs.
- Some horses showed exaggerated sinking of the hindquarters when pressure was applied over the tubera sacrale (jumper's bump).
- When palpating the thoracolumbar region or tubera sacrale, spasm of the epaxial muscles (pictured right) is common.
- Hoses may show restricted flexibility of the thoracolumbar region or became agitated despite showing a normal range of motion (I think this was measured in the clinic via a treadmill).
- Reluctance to stand with one hindlimb flexed, bearing weight on the other limb, or reluctance to allow one or both hindlimbs to be picked up was seen in ~25% of horses.
- When examined moving in hand on a hard surface, the most common feature was reduced hindlimb impulsion. Sometimes seen:
- rolling hindlimb gait
- moving wide behind
- moving close behind
- few plaiting
- more than one gait abnormality
- rolling hindlimb gait
- Showing lameness in only one hindlimb is not associated with hip/sacroiliac pain. It was only seen when a specific problem was identified in that hindlimb (e.g., hock)
- Some horses turn abnormally about their own length, show stiffness or a tendency to pivot on the forelimbs, or are reluctant to cross the hindlimbs normally.
- Stiffness and poor hindlimb impulsion are observed on the lunge, but not necessarily one-sided lameness (unless attributed to another cause).
- Bucking at the canter is common.
- Some horses break to canter rather than increase hindlimb impulsion, whereas others show a poor quality canter manifest as four-time canter, repeatedly changing legs behind, or becoming disunited.
- Sometimes problems are only apparent when ridden.
- Horses often feel worse to a rider than they look, even to a skilled, experienced observer.
- Lateral work (e.g., shoulder-in, half-pass) is particularly difficult. Canter is stiff and stilted, often four beat and difficult to maintain. Some horses canter crookedly on three tracks.
- Some of these horses re also extremely reluctant to go forward.
S.J. Dyson and R. C. Murray. Clinical Features of Pain Associated with the Sacroiliac Joint Region: A European Perspective In: 50th Annual Convention of the American Association of Equine Practitioners, 2004.
Understanding sacroiliac pain Horse and Hound
Sacroiliac Pain from The Horse magazine
Back pain and the sacroiliac joint in horses from Myhorse.com