# Validity of the Enode Sensor and My Jump 3 App for Assessing Countermovement Jump Performance
## 3 Results
The linear regression analysis between the Enode Sensor (EN) and the Force Plate (FP) demonstrates a strong predictive relationship, suggesting that the Enode Sensor closely approximates measurements from the Force Plate. The model fit results reveal a high degree of correlation, with an R value = 0.972 and an R\({}^{2}\) = 0.945, indicating that approximately 94.5% of the variance in Enode Sensor measurements can be explained by Force Plate values. The overall model is statistically significant, as indicated by the F-statistic (F(1, 27) = 466, \(p\) < 0.001), affirming the strength and reliability of the predictive model (Table 7). \begin{table}
\begin{tabular}{l c c} \hline \hline
**Correlation Analysis** & **EN vs. FP** & **MJ vs. FP** \\ \hline Pearson’s r & 0.972 & 0.986 \\ Spearman’s rho & 0.977 & 0.988 \\ \hline \hline \end{tabular} Notes: EN—Enode Sensor; MJ—My Jump 3; FP—Force Plate.  
\end{table} 
Table 6: Correlation analysis: Enode Sensor, My Jump 3, and Force Plate. Figure 3: Correlation and density distribution of vertical jump measurements: Enode Sensor vs. Force Plate. Notes: Corr—Pearson correlation coefficient; EN—Enode Sensor; FP—Force Plate; *** denotes significant correlation at the level of \(p\) < 0.001. An examination of the model coefficients further supports this strong relationship. The intercept is 1.85 (SE = 2.161, \(p\) = 0.398), indicating that the baseline difference between the two methods is minor. The slope for the Force Plate predictor is 1.01 (SE = 0.047, \(p\) < 0.001), which is close to 1, suggesting a nearly one-to-one relationship between Force Plate and Enode Sensor measurements. The 95% confidence interval for the slope (from 0.913 to 1.11) further reinforces this strong agreement, highlighting the Enode Sensor's reliability in measuring vertical jump heights in comparison to the gold-standard Force Plate. These findings underscore the Enode Sensor's potential as an accurate and cost-effective alternative for vertical jump assessment, providing robust data closely aligned with traditional laboratory-based Force Plate measurements. The linear regression analysis between the My Jump 3 App and the Force Plate also demonstrates a remarkably strong predictive relationship, indicating that My Jump 3 provides measurements closely aligned with those from the Force Plate. The model fit statistics show an exceptionally high degree of correlation, with an R value of 0.986 and an R\({}^{2}\) value of 0.973, meaning that 97.3% of the variance in My Jump 3 measurements can be explained by Force Plate values. The overall model is statistically significant, with an F-statistic of 966 (F(1, 27) = 966, \(p\) < 0.001), confirming the robustness and reliability of this predictive model. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline \multirow{2}{*}{**Device**} & \multirow{2}{*}{**R**} & \multirow{2}{*}{**R\({}^{2}\)**} & \multirow{2}{*}{**F** **Statistic**} & \multirow{2}{*}{**Sig.**} & \multicolumn{2}{c}{**Intercept**} & \multicolumn{1}{c}{**Slope for Predictor**} & \multicolumn{1}{c}{**95\% Confidence**} \\  & & & & & **(Estimate \(\pm\) SE)** & **(Estimate \(\pm\) SE)** & **Interval for Slope** \\ \hline Enode vs. Force Plate & 0.972 & 0.945 & 466 & 0.001 * & 1.85 \(\pm\) 2.161 & 1.01 \(\pm\) 0.047 & from0.913 to 1.11 \\ My Jump 3 vs. Force Plate & 0.986 & 0.973 & 966 & 0.001 * & 1.64 \(\pm\) 1.476 & 0.992 \(\pm\) 0.031 & from 0.927 to 1.06 \\ \hline \end{tabular}  
* Notes: R—Pearson correlation coefficient; R\({}^{2}\)—Coefficient of determination; F—F-statistic for model significance; Sig—Significance level; “denotes significant correlation at the level of \(p\) < 0.001; Intercept (Estimate \(\pm\) SE)—Baseline measurement with standard error; Slope for Predictor (Estimate \(\pm\) SE)—Rate of change in device measurement per unit of change in Force Plate; 95% Confidence Interval for Slope—Precision range for slope estimates.  
\end{table} 
Table 7: Regression analysis of Enode Sensor and My Jump 3 App against Force Plate measurements.