# Collection and Advice on Basketball Field Tests--A Literature Review
## 4 Discussion
### Practical Advice on Test Implementation and Interpretation
#### 4.2.1 Jump Tests  
Jumping ability is a common physiological and biomechanical factor among basketball players; therefore, jump tests are common methods of testing reactive power of the lower limbs [48; 49; 50]. They are some of the most popular tests among basketball experts because they do not require expensive tools and are easy to perform on a court. According to [PERSON] et al. [49], improvement of the jump ability can be achieved by strengthening the overall musculoskeletal state. In the case of jump tests, our most important observation is that CMJ is a practical test to monitor players' current conditions. Using CMJ, experts can monitor fatigue, loss of explosive force, ANSr, and interlimb asymmetries. Based on quantitative biomechanical analyses, we think that trainers have to pay more attention to teaching the correct technique of jumping to save energy. During testing, experts must clarify the aim of the jumping (e.g., height or explosiveness) and should precisely determine the jumping protocol (e.g., CMJ AS or CMJ NAS, recovery time) because different protocols will lead to inconsistent results. Results from previous studies are inconsistent as to whether anthropometric parameters might influence vertical jump (VJ) performance. Counter Movement Jump (CMJ) is a very well-researched, although simple test. Although normalizing the numerical results of CMJ might not be necessary [51], anthropometry [52] and maturity status [53; 54] appear to have a significant impact on jump performance. Furthermore, whereas body-mass normalized CMJ force is not a determining factor to detect sex differences between strength-matched subjects, eccentric phase impulse and concentric phase peak power appear to be influenced by sex differences independent of matching strength levels [54]. VJ performance is more related to motor skills and abilities than to training history [55]. For instance, VJ performance markers not only positively correlate (\(r\) = 0.812, \(p\) < 0.001) with explosive leg power [14; 45], but the increase in fatigue is directly proportional to the decrease in eccentric CMJ variables [14], indicating that eccentric jump variables have the potential not only to measure the loss of explosive force but also to detect overtraining or overreaching [56]. It is well known that reactive muscle strength is dependent on the eccentric phase. Although a deeper squat helps reach the maximum height, different strategies are needed to increase the jumping speed [57]. Increases in eccentric and concentric joint work and total joint work correlated with an increase in CMJ height [58; 59; 60]. However, concentric vs. eccentric joint work is a better indicator of CMJ performance, and it might not be surprising that the knee is the most important joint-level determinant of CMJ height [58]. Jump tests are also used to evaluate Automatic Nervous System responses (ANSr) that serve as a reliable picture of the player's current condition [61; 62]. For example, [PERSON] et al. [63] found that the 5 Vertical jump test is sensitive for ANSr, i.e., a 5-min recovery was not enough for the onset of vagal tone (parasympathetic modulation), suggesting that the resting time between jumps is crucial. Overall, if experts want to measure reactive strength or even just the height and force values of jumps, they should give enough recovery time to avoid the high response of sympathetic modulation. Although quantitative measures of the CMJ test with and without arm swing (CMJ AS, CMJ NAS, respectively) correlated to a large or very large degree [64], CMJ AS might be a better indicator of longer-term changes in performance, e.g., alterations in performance across training phases [65]. RSIMod, adopted from the Reactive Strength Index (RSI), is one of the most common, easily calculated variables of CMJ that reliably assesses an athlete's explosiveness by providing independent information from the CMJ NAS and CMJ AS [64].