The cause and best treatment option for mechanical low back pain due to disc degeneration remains unsolved, despite `spinal fusion' being the gold standard of surgical treatment, post conservative care, for a very long time. However, the potential drawbacks of spinal fusion and the ongoing evolution in the understanding of normal and symptomatic spine biomechanics, biology and mechanobiology in conjunction with the advancements in material sciences, and tissue engineering has led to a change in the clinical perspective towards treatment methodologies for spinal disorders. Clinically, a gradual shift in philosophy is being observed from a `one size fits all', i.e. spinal fusion for all patients with symptomatic low back pain to a `customized approach', i.e. patient and indication specific treatment modalities for spine care. This philosophy has laid the ground for concepts of `motion preservation' and `dynamic stabilization', the former being an established treatment modality in orthopedics for a long time. The aim of the current study is to perform a comprehensive scientific investigation to understand, evaluate and establish the in vitro biomechanical characteristics and performance of indication specific treatment modalities incorporating the concept of Posterolateral Disc Arthroplasty and Posterior Dynamic Stabilization for the treatment of symptomatic mechanical back pain. The results of this comprehensive study may help the clinicians to make an informed decision while selecting and designing a treating modality for their patients. To this end, the current thesis was undertaken to study the biomechanics of indication specific treatment modalities like motion preservation and dynamic stabilization with a goal to guide clinical and product development decision making. Through the comprehensive biomechanical investigation conducted in the current thesis we were able to theoretically prove the importance of a customized approach towards the treatment of spine care. Also, the most important conclusion of the biomechanical investigation was the fact that Range of Motion results alone are not sufficient to draw significant conclusions. It is imperative that in depth analysis of the quality of motion through the determination of instantaneous center of rotation is extremely important. Previous studies have shown only a single center of rotation between the extremes of motion which is also insufficient as the end points do not determine the path taken to reach the endpoints. This in depth analysis is also important for biomedical engineers to design and develop physiologically viable implants that will mimic the performance of the physiologic spine. Clinical studies are extremely important as a next step towards validating this customized approach towards spine care.