Viscoelastic Properties of the L3-L4 Myofascial Tissue in Ankylosing Spondylitis Patients

Ankylosing spondylitis (AS) is a degenerative rheumatological disorder that mainly affects the spine. It has been reported that different degrees of human resting myofascial tone (HRMT) would affect spinal stability and may predispose to the respective curvature deformities of adolescent idiopathic scoliosis (AIS) and the enthesopathy of ankylosing spondylitis (AS). Although osteoligamentous impacts are prominently recognized in many chronic spine and low back conditions, no research has been performed on the possible role of passive axial (spinal) myofascial tone as a causative factor. In this particular study, the passive muscle properties of the lower lumbar regions of 24 healthy adults and 24 adult AS subjects were examined. Our recent publications examined the linear elastic properties among normal and AS subjects. In this study, those analyses are expanded to include detailed analysis and correlations of the linear elastic property of stiffness to two viscoelastic properties: stress relaxation time (SRT) and creep. Analyzed data supports the hypothesis that resting muscle properties of the lower lumbar muscles hold significance in differentiation of human back health between healthy and diseased subjects, but more testing should be performed to support this study’s results.