Adolescent Idiopathic Scoliosis (AIS) is a condition of the spine, often characterized by a three- dimensional spinal deformity. Treatment usually involves interventions like exercise, bracing, or if necessary, surgery. Often bracing is prescribed to stop curve progression so that surgery can be avoided. Traditional scoliosis braces are usually rigid devices, which displace the spine to the desired corrective position. With efficacies over 90%, these braces can be quite effective when worn enough. Unfortunately, the activities of daily living (ADL) for patients are reduced drastically when wearing a brace, and as a consequence compliance towards the braces is low. Since AIS develops in around 3% of all adolescents, of which approximately 10% has progressive curves that require treatment of some sort, the need for effective, comfortable bracing is high. To increase the ADL of patients, the current focus has been shifted towards designing a compliant scoliosis brace that can provide needed corrective forces and allow motion.
This thesis focusses on the evaluation of spinal motions through the design of a motion capture experiment. The goal of this work is to provide general knowledge about these spinal motions for clinicians, researchers and mechanism designers, such that they can make use of the provided analysis for the design of a new, compliant scoliosis brace. Parts of this analysis are implemented in a brace design quantification strategy, which can be used to facilitate such a brace design project. The key contribution of this master thesis is the characterization of spinal motions for specific vertebrae, to provide substantial kinematic data for the design of a compliant scoliosis brace.