Sitting has become the most common work posture in todays society, and workstations requiring prolonged sitting are associated with seated discomfort. Discomfort has been identified as a precursor to pain and, as such, seated discomfort may, if sustained, lead to pain in the related body regions. Low back pain is the most common type of pain reported in adults, and pose a significant societal cost. The variability of biological systems has been shown to change with pain and disease. This master thesis concerns the variability of seated postural control during the development of seated discomfort, by means of linear and nonlinear analysis techniques. Discomfort ratings, kinetic and kinematic data were sampled from 9 healthy, male subjects during prolonged sitting. Correlation analysis was performed to determine the correlation of each parameter to discomfort. Results showed that the amount of variability, was positively correlated to discomfort, whereas complexity was negatively correlated with discomfort, for all variables. These findings suggest that objective postural parameters are interrelated with subjective discomfort, and that the importance of the dynamics of seated posture may challenge the idea of a static ideal seated posture.