Human Silly Putty Treating Sacroiliac Joint Upslips A lthough ‘creep’ is an engineering term, it also applies to human tissue…the lumbopelvis in particular. Spinal and sacroiliac ligaments, joint capsules, facet cartilages and especially intervertebral discs are viscoelastic and are somewhat similar to silly putty. Leave a ball of putty on a table overnight and by the next morning it’s deformed into a flattened pancake. So be it with humans (Fig. 1). We’re taller in the morning than at bedtime, primarily due to disc and fascio-ligamentous deformation that occurs throughout the day. Of course, silly putty is much creepier than discs, fascia or ligaments but, in time, gravity combined with injury or overuse, will deform, and sometimes strain, the body’s connective tissues. As ligamentous creep turns to strain and the tissue’s anti-gravity function fails, ligamentous laxity may affect bony alignment and, if the brain perceives that as a problem, the person may experience muscle guarding or pain. Contrary to what many docs tell their patients, most low back and pelvic pain does not result from a single traumatic 18 By Erik Dalton, Ph.D. lifting, bending or sports injury, but rather from cumulative viscoelastic creep due to lack of rest between loading cycles. According to Bogduk and Twomey, “After prolonged strain, spinal ligaments, joint capsules, and IV discs of the lumbar spine may creep, and may be liable to injury if sudden forces are unexpectedly applied during the vulnerable recovery phase.