Multimodal Bio-mechanical Analysis of Adult Spinal Deformity With Sagittal Plane Misalignment

A good understanding of the principles of balance is vital to achieve optimal outcomes when treating spinal disorders. A complex interaction of the neuromotor system and muscular recruitment is necessary for ergonomic balance and deliberate displacement of the human body. Sagittal plane misalignment in spinal deformities challenges balance mechanisms used for maintenance of an upright posture. The occurrence of postoperative complications after spinal deformity correction like under-correction of sagittal misalignment, postoperative reciprocal changes in thoracic kyphosis, proximal junctional kyphosis and failure of instrumentation are possibly due to the current state-of-the art inadequate diagnostic work-up. Investigators do not fully understand the roll of vision and exact strategy of recruitment of neuromuscular units (trunk, pelvis, lower limbs) in patients with sagittal plane misalignment during standing and walking. To understand this, a dynamic evaluation of individuals with spinal deformities is needed. Currently there is only very little research performed in the field of clinical balance tests and instrumented movement analysis in patients with spinal deformity. The challenge for future studies is to further unravel the relation between trunk and lower limb movements, grouped into functional movement patterns. Moreover, additional information on trunk and lower limb kinetics and muscle activity (using dynamic electromyography (EMG)) will highly contribute to the understanding of this functional relationship, and will provide more in-depth insights into compensatory mechanisms of the trunk versus the lower limbs and vice versa.