## 5 Conclusions  
In conclusion, the results of this study provide valuable insights into the biomechanical aspects of badminton forehand smashes and the progression of skills among novice and skilled players. It is evident that with progressive years of training, significant improvements in smash quality are achieved. Skilled players exhibit a remarkable 60.2% increase in maximum shuttlecock speed (V\({}_{\text{max}}\)), which is accompanied by substantial reductions in shuttlecock clearance height (H\({}_{\text{p-n}}\)) and the flight angle at release (A\({}_{\text{shuttle}}\)). These enhancements are closely linked to full-body control mechanisms, including the use of jumping techniques, the formation of a full-body tension arc, increased trunk rotation, and a distinctive whip-like control pattern.  
Moreover, the study identifies specific determinants, such as consistent positioning, racket angle at impact, and range of motions (ROMs) in various joints, that significantly contribute to smash quality. Skilled players demonstrate superior performance in these determinants compared to novices, highlighting their importance in the skill development process.  
The concept of a full-body tension-arc and the whip-like control pattern emerge as crucial factors for generating explosive power in the smash. Specific to badminton smash, due to the inertia effect, rapid trunk, and shoulder rotations in the early smash phase cause passive elbow flexion and wrist over-extension, reinforcing the SSC effect for a more potent whip-like smash. Focusing on trunk and shoulder control in initial stages simplifies the learning of the four-segment whip-like control, potentially enhancing training effectiveness. This biomechanical understanding extend beyond badminton and can be applied to other sports skills related to throwing or smashing.  
Finally, the study emphasizes the importance of mastering positioning, enhancing joint control, and optimizing the whip-like control pattern for novice players. Future research involving professional players and gender-based differences would further enrich our understanding of badminton smash mechanics. Overall, this study bridges the gap between scientific research and coaching practice, providing valuable insights for coaches and players seeking to improve their badminton forehand smashes.  
**Author Contributions:** Conceptualization, F.L., S.L. and G.S.; methodology, F.L., S.L., X.Z. and G.S.; software, X.Z. and G.S.; validation, S.L., X.Z. and G.S.; formal analysis, F.L., S.L. and G.S.; investigation, F.L., S.L. and G.S.; resources, X.Z. and G.S.; data curation, F.L. and S.L.; writing--original draft preparation, F.L. and G.S.; writing--review and editing, F.L., S.L., X.Z. and G.S.; visualization, F.L. and G.S.; supervision, G.S.; project administration, S.L. and G.S.; funding acquisition, X.Z. and G.S. All authors have read and agreed to the published version of the manuscript.  
This research project was supported by Xinzhou Teachers' University (China) and the Discovery Grant of National Sciences and Engineering Research Council of Canada (NSERC) (Grant #: RGPIN-2014-03648).  
The study was carried in accordance with the policy of the University of Lethbridge and the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans (protocol number: #2014-029; approval period: 5 March 2014 to 31 March 2019).  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
The data presented in this study are available upon request and after appropriate IRB approvals. The data are not publicly available due to privacy.  
We would like to thank all the subjects of the study who donated their time and expertise.  
The authors declare no conflict of interest.