# At the End of a Slippery Slope: A Pilot Study of Deceleration Mats for Snow Tubing
## 3 Results  
A total of 78 tests trials were performed. Data were collected for 75 tests in which the participants descended the tubing run and rode over the deceleration mats (when used); for three test trials, the data acquisition system did not record or the snow tube did not reach the run-out area. The mean (\(\pm\)standard deviation) speeds as the riders entered the run-out was 9.5 (\(\pm\)1.8) m/s with a range of 5.0 to 14.1 m/s. There was no difference in speed entering the run-out between _flat_ and _folded_ conditions (\(p\) = 0.24). The deceleration was not abrupt in any test, the deceleration mats did not cause the riders to fall off the snow tubes, and there was no observable forward motion of the rider relative to the snow tube. There were no significant differences between the _ribs_ and _projections_ conditions across all kinematic metrics and the effective coefficient of friction (COF); see Table 1. The deceleration and COF for the _folded_ condition were significantly larger than the _flat_ and no mat conditions. When the deceleration mats were in the _folded_ condition, the snow tube and rider rotated back slightly as they compressed the folded section of the mat and moved past the fold; see Figure 3d. Though the snow tube and rider rotated slightly forward (in the pitching direction) after passing the folded section, the magnitude of angle change was \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \begin{tabular}{c} **Deceleration** \\ **Mat** \\ **Condition** \\ \end{tabular} & \begin{tabular}{c} **No. of** \\ **Tests** \\ \end{tabular} & \begin{tabular}{c} **Speed** \\ **Entering** \\ **Run-Out** \\ \end{tabular} & \begin{tabular}{c} **Peak Deceleration** \\ **eration** \\ \end{tabular} & \begin{tabular}{c} **Pitch Over** \\ **Rotation** \\ **Rate** \\ \end{tabular} & \begin{tabular}{c} **Change in** \\ **Hand to** \\ **OCM** \\ **Distance on** \\ **Mat** \\ \end{tabular} & \begin{tabular}{c} **Effective** \\ **(Average)** \\ **Coefficient** \\ **in Mat Area** \\ \end{tabular} \\ \hline \begin{tabular}{c} **No Mat** \\ **Flat** \\ _Rils_ \\ _Projections_ \\ _Combinal_ \\ \end{tabular} & 11 & 8.5 (0.7) & 0.6 (0.3) & – & – & 0.08 (0.03) \\ \hline \begin{tabular}{c} **No Mat** \\ **Flat** \\ _Rils_ \\ _Projections_ \\ _Combinal_ \\ \end{tabular} & 11 & 9.7 (1.9) * & 3.5 (0.6) * & 12 (16) & 1.4 (0.4) & 0.09 (0.06) \\ \hline \begin{tabular}{c} **Jeff** \\ _Rils_ \\ _Projections_ \\ \end{tabular} & 18 & 9.2 (1.8) * & 3.2 (0.8) * & 15 (12) & 1.4 (1.2) & 0.11 (0.10) \\ \hline \
\begin{tabular}{c} **Jeff** \\ _Rils_ \\ _Projections_ \\ \end{tabular} & 29 & 9.4 (1.8) * & 3.3 (0.8) * & 13 (13) & 1.4 (0.7) & 0.10 (0.07) \\ \hline
\begin{tabular}{c} **Jeff** \\ _Projections_ \\ _Combinal_ \\ \end{tabular} & 17 & 9.7 (1.9) * & **5.1 (1.5) * & 18 (20) & **3.7 (1.5)** & **0.24 (0.13) * \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Mean kinematic data (standard deviation) from the snow tube interactions with the deceleration mats during testing. The effective coefficient of friction is based on the average deceleration across the deceleration mats. The kinematic data are presented for the resultant of the components along the snow surface. There were no statistically significant differences between _ribs_ and _projections_ conditions; the _combined_ rows include all of the _ribs_ and _projections_ conditions for a particular mat geometry. Bold values indicate a statistically significant difference between _flat_ and _folded_ conditions (\(p\) < 0.05). (*) indicates a statistically significant difference compared to the _no mat_ condition (\(p\) < 0.05). small (less than 7\({}^{\circ}\) across all tests) and not observable on the video. The average pitch forward for the COM was 6\({}^{\circ}\) (95% confidence interval: 4 to 7\({}^{\circ}\)) after the deceleration mats in the _folded_ condition. For comparison, the average pitch forward was 4\({}^{\circ}\) (95% confidence interval: 0 to 7\({}^{\circ}\)) for the _flat_ condition; there were no statistical differences between the two mat conditions.