Sacroiliac joint loading and pelvic deformation: How rigid is the pelvis?

摘要

Sacroiliac joint injuries are a significant cause of poor performance and are estimated to occur in about 8% of Standardbreds in racetraining (Dalin et al. 1985) and 15% of show/jumpers, hunters, eventing, dressage and other competitive horses (Jeffcott etal. 1985). In a necropsy study of 36 Thoroughbred racehorses that died on California racetracks, 100% of the horses had evidence of variable degrees of sacroiliac joint osteoarthritis (Haussler ef al. 1999). In horses, the ante mortem diagnosis of sacroiliac injuries is often based on ruling out other possible causes of pelvic limb lameness or poor performance, since there is not one specific test that clearly identifies a horse with sacroiliac dysfunction. Affected horses often have a vague history of poor performance that is characterised by mild pelvic limb lameness, refusal of jumps, poor impulsion, back stiffness, poor croup muscling, and a reduced ability to run at high speeds (Jeffcott et al. 1985). Direct measures of equine sacroiliac joint motion and the effects of sacroiliac ligament injuries are limited (Denoix 1992). The majority of motion present at the sacroiliac joint is thought to be flexion and extension; however, small combinations of lateral bending and axial rotation at the sacroiliac joint are possible (Rooney 1981; Denoix et al. 2001). However, the interaction between sacroiliac joint and pelvic mechanics is poorly understood in the pathophysiology of performance-limiting injuries (Goff et al. 2008). The objective of this study was to measure pelvic deformation during in vitro sacroiliac joint movements using quantified forces and moments.