## 4 Discussion
### Association between CMRJ and IMTP  
The present study discovered a statistically significant correlation between IMTP PF and JH-1 in the CMRJ (\(r\) = 0.54, \(p\) = 0.002), which substantiates the results of previous research [20]. This finding was expected since the IMTP test evaluates the maximal force an athlete can produce, which is also crucial for the power output during the propulsive phase of a jump [20]. Additionally, a noteworthy correlation was established between F@ 300 ms and JH-1 (\(r\) = 0.55, \(p\) < 0.001), predominantly aligning with previous studies that reported a significant relationship between F@ 250 ms during IMTP and CMJ height (\(\rho\) = 0.35) [32]. Specifically, the association between the IMTP F@ 300 ms time frame and JH-1 may be due to the similar duration of the propulsive phase in a CMJ (or CMRJ1), which is typically between 250 and 280 ms [33]. Since the propulsive impulse is a determination factor for JH, the ability to generate considerable force within these critical time frames appears to be a key attribute influencing jump performance [25]. This notion was further supported by the significant positive relationships between IMTP force variables and CM depth during the CMRJ test (\(r\) = 0.55 to 0.61, \(p\) \(\leq\) 0.001), indicating that a deeper CM depth permits athletes more time to generate larger forces prior to take-off [2]. The correlation between JH-2 and IMTP PF was moderate and non-significant in the present  
Figure 7: Differences in 505 COD time between the higher and lower groups in JH-2 and RSI during the second jump of the CMRJ test. * Significantly different between groups (\(p\) < 0.05).  
study, aligning more closely with prior research that has shown moderate associations between IMTP PF and DJ height at 0.3 m (\(r=0.429\), \(p\leq 0.01\)) and 0.4 m drop heights (\(r=0.364\), \(p\leq 0.05\)) [22]. This discrepancy may be attributed to the unique methodology of our CMRJ test, where athletes fell from individually determined heights after the initial jump, rather than from a standardised fixed drop height. This modification likely introduced additional challenges compared to the conventional DJ test, potentially affecting some athletes' ability to achieve optimal rebound heights (JH-2) [1]. Nevertheless, the median split analysis, splitting subjects via both JH values, revealed that the IMTP PF, F@ 200 ms and F@ 300 ms values were significantly larger in the higher group (\(g\geq 0.70\), \(p\leq 0.05\)). Put simply, athletes who jump higher in both CMRJ jumps have at least a moderate likelihood of generating greater forces in the IMTP test.  
Contrary to the expectation, RSImod/RSI values did not significantly correlate with any IMTP force measures, deviating from previous studies that have established a significant association [22; 32; 34]. The median split analysis indicated non-significant trivial to moderate differences (\(g\leq 0.72\), \(p\geq 0.08\)) in IMTP performance between higher and lower groups, when split by RSImod and RSI metrics (Figures 2 and 5). This lack of significant differences is likely explained by the fact that RSImod and RSI may not directly translate to the expressions of maximal force production in an IMTP, whereby the force is generated from a controlled, isometric context, despite both RSImod and RSI being relevant for dynamic performance or serving as a reflection of jump strategy [2]. Furthermore, the RSImod and RSI are susceptible to manipulation through alterations in jump strategies rather than pure absolute strength capacity [2]. Therefore, the changes in jump strategies among subjects may have resulted in differences in associations between IMTP and CMRJ measures, and to the extent of magnitude of these associations [20].