Investigating the effects on postural control from prolonged resting in different horizontal positions

Impaired postural control can be detrimental to an individuals well-being yet its relationship with prolonged resting remains underexplored. To gain insight on the effects of prolonged resting this thesis presents a posturography study that investigated which effects prolonged resting has on postural control. To accomplish this, this thesis had six aims: 1. Conduct a literature study and select stabilometric parameters with good test-retest reliability: The parameters chosen for analysis were: root mean square (RMS) acceleration, mean center of pressure (CoP) velocity, quotient of amplitudes, principal sway direction, 95% confidence ellipse area, and the DFA-alpha coefficient for the CoP. 2. Design an experimental study and write a study protocol: Participants were instructed to stand still for two minutes while deafened and blindfolded, with their feet together and arms relaxed after resting in either a supine, left-ear down or right-ear down position for 5 minutes. 3. Recruit up to 25 healthy participants for the experimental study: Twenty healthy participants, aged 18–65, were recruited with one excluded due to missing data. 4. Conduct the measurements: Measurements were performed using Moticon SCIENCE insoles and the Xsens MTw™ Awinda Inertial Measurement Unit (IMU). Two IMUs were used: one on the L5 and another on the right shank. 5. Evaluate the plantar pressure data by comparing the Moticon insoles to the gold standard pressure plate: The Moticon SCIENCE insoles were qualitatively validated against the Zebris FDM 1.5 pressure plate, finding good agreement for a select few participants. 6. Analyse the data, then compute the stabilometric parameters and perform a statistical investigation with the parameters as a basis: The ac3 quired data was filtered and processed to compute the selected stabilometric parameters. A two-way ANOVA was performed with significance level α = 5% to examine differences in postural control among three resting positions: supine, right-ear down (RED), and left-ear down (LED). The post-hoc analysis revealed significant differences in the anterior-posterior CoM RMS acceleration and principal sway direction between supine and RED/LED positions. This thesis successfully met its objectives, providing new insights into how prolonged resting influences postural control. While the experimental design and selected parameters were effective for detecting some differences, a majority of the parameters did not reveal any significant differences. The work done in this thesis provides a foundational framework for future studies and highlight areas for improvement in both the experimental protocol and parameter selection needed to further explore this paradigm.