Trunk center of mass was defined as the location of the center of mass of the trunk in space. Right and left center of pressure (COP) was the location of the COP of each foot on the surface of the force plates. The dependent variables included the average T_ANG, T_AVEL, T_COM, and average speeds of right and Panobinostat mouse left foot COP. T_ANG was calculated by determining the average differences between the minimum trunk angle and maximum trunk angle during trials. T_AVEL was calculated by dividing the sum of the changes in trunk angle during the trial by the total trial time. Similarly, T_COM and COP speeds were calculated by dividing trunk center of mass and foot COP trajectories by the
trial time. SPSS statistical analysis software v.19.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the data, with the aim of comparing the T_ANG, T_AVEL, T_COM, and right and left foot selleck COP speeds between the three sitting surfaces. A one-way repeated measures MANOVA was used to determine differences in the
dependent variables between the three sitting conditions. For significant main effects, post hoc pairwise comparisons were performed using a Bonferroni correction to locate the differences between conditions. A critical α probability level of 0.05 was used for all analyses. No significant main effects were found for the T_ANG around the ML axis (p = 0.331), AP axis (p = 0.513), or longitudinal axis (p = 0.108) ( Fig. 1). No significant main effects were found for the T_AVEL around the ML axis (p = 0.053) ( Fig. 2) and T_COM in the AP direction
(p = 0.121) ( Fig. 3). Significant main effects for T_AVEL around the AP axis (p = 0.037) and the longitudinal axis (p = 0.040) were found ( Fig. 2). In addition, L-NAME HCl T_COM in the ML (p < 0.001) and longitudinal directions (p < 0.001) were also significant ( Fig. 3). Post hoc pairwise comparisons revealed differences in T_AVEL and T_COM between sitting surfaces. The ball condition demonstrated greater T_AVEL around the AP axis than the chair condition (p = 0.005). In addition, the ball condition demonstrated greater T_AVEL around the longitudinal axis compared to the air-cushion (p = 0.050) and the chair conditions (p = 0.037). Furthermore, the ball condition had greater T_COM in the ML direction compared to the air-cushion (p = 0.001) and the chair (p = 0.001) conditions. In the longitudinal direction, the ball condition had greater T_COM compared to the air-cushion (p = 0.004) and the chair (p = 0.007) conditions. The air cushion also demonstrated greater T_COM in the ML direction than the chair condition (p = 0.008). Table 1 shows the means ± SD of the COP speeds for the three sitting conditions. No significant main effects were found for the average speeds of foot COP in the ML direction for the right (p = 0.458) and left (p = 0.489) feet. However, significant main effects were found in the AP direction for both the left (p = 0.006) and right (p = 0.004) feet.