Balance disorders and falls are prevalent among multiple pathologies that affect the musculoskeletal or sensorineural systems. Annually, fall-related injuries put excessive economic burden on society and yet, current clinical balance assessment tools based on functional tests are inaccurate and have limited association with fall risk. Therefore, there is a growing need of an accurate balance and fall risk assessment tool for clinical use. The primary purpose of this research was to develop an accurate Center of Pressure (COP) based balance assessment tool to study postural instability and fall risk. Chapter 1 aimed at development of the COP based tool using cost effective equipment- a Wii Balance Board (WBB) and testing its accuracy and errors. The result of this study indicated that the WBB tool is reliable in assessing balance and the linearity and hysteresis errors in WBB tool are higher than force plates but it compares well in terms of cost, portability and availability. Chapter 2 aimed at assessing the relation between the radiographic parameters of balance, COP metrics, and health related quality of life in adults with spinal deformities. The results of this investigation revealed that just like radiographic parameters, COP metrics could help explain some variability in symptoms in patients with comparable extent of deformity. Chapter 3 attempted to establish a threshold value of COP metrics for binary classification of fall risk in patients with multiple sclerosis (MS). The findings of this study highlighted path length as an excellent predictor of future falls with high test accuracy, sensitivity and specificity. This dissertation concludes that the WBB tool has the potential to revolutionize balance and fall risk assessment in clinical fields such as geriatrics, rehabilitation, neurology, and orthopedics.