From the Archives of Zagreb School of Biomechanics: Measuring Biomechanical Properties of Lumbosacral Joint Specimens

A specific part of human body is focused; a lumbar spine segment with surrounding tissues, biomechanics of which is crucial for maintaining the upward erect body posture and moving the body in the intended direction by means of walking, running and other locomotor modalities. The pelvic segment possesses a pivotal role in the walking process, with biomechanics of the lumbar spine being crucial for realizing dynamic spatialDynamic spatial (3D) movements. Uprising of humans on lower legs during evolution has challenged this body part by subjecting it under big mechanical strain, as best witnessed, unfortunately, by neurosurgical praxis treating spinal injuries resulting from mechanical overloads, a consequence of sports training or occupational tasks. Zagreb school of biomechanics, appearing in second half of twentieth century, is introduced shortly. Approaches of anatomy, orthopedics and mechanical engineering were integrated. Initially viewed as essentialy a static construction, the spine was modeled subsequently as a dynamic mechanical structure. An archival example of in vitro type measurements of mechanical properties of lumbosacral joint speciments is presented in some detail, in the context of evaluating specific surgical interventions. Interlaminectomy has been found a procedure of choice in the treatment of disc hernias of the lumbar spine. Non-invasive in vivo measurements of spine kinematics during normal gait were performed later.