Patients with scoliosis deformity can be evaluated from a biomechanical viewpoint by measurement of spinal morphology, back surface topography, and changes in these measurements both acutely and over time. In addition, the forces acting on the spine can be estimatedin vivo.Many ethical and practical challenges have been overcome, and these measurement techniques have provided information on spinal deformity and its treatment. Further insights have come from biomechanical analyses of these measurements, and complementary modeling studies. This study reviews the available methodologies and the progress that has been made toward using these methods in assessing outcomes in treatment. Possible future directions forin vivomeasurements are suggested for studies of etiology, growth regulation, progression of deformity, three-dimensional assessment of treatment outcome, and monitoring of individual patients.