Horse anatomy
Loin
The area between the back and the croup. Helps transfer power from the hindquarters.
A closer look
The loin is the short section of the back between the last rib and the croup, over the lumbar vertebrae. Unlike the rest of the back, it has no ribs underneath to support it, so it relies on strong muscles. Horse people describe a short, well-muscled loin as a strong coupling.
Why it matters
The loin passes the push from the hind legs forward to the rest of the body. Because it isn't supported by ribs, it is not meant to carry the saddle or the rider's weight.
Care tip
Check that the back of the saddle ends before the loin begins, roughly above the last rib. When grooming, use gentle pressure here and notice if the horse flinches or dips its back.
Common mistake
Sliding back toward the horse's hips, whether in the saddle or riding bareback, puts weight right on the loin. Sit in the middle of the back, over the ribs.
Fun fact
Most horses have six lumbar vertebrae in the loin, but some Arabian horses have only five.