Explosive lower-limb strength predicts serve performance in competitive junior tennis players

Abstract

Serve velocity is a key performance determinant in tennis and relies on effective kinetic-kinematic energy transfer initiated by the lower limbs. While previous research has predominantly emphasized upper-extremity contributions, the neuromuscular characteristics of the lower limbs, particularly during the loading phase of the serve, remain insufficiently examined. Seventeen elite junior male tennis players participated in this study. Serve velocity was measured using a radar gun, while lower-limb neuromuscular performance was assessed via isokinetic knee and hip flexion–extension torque testing at angular velocities of 60°, 180°, and 240°·s⁻¹. Countermovement jump (CMJ) height was evaluated as a functional indicator of rapid force production capacity. Pearson correlation and multiple linear regression analyses were conducted to identify predictors of serve performance. Serve velocity was significantly associated with isokinetic torque outputs of the knee and hip joints across multiple angular velocities, as well as with CMJ height (p < 0.05). Greater knee flexion-extension and hip flexion-extension torque capacities were consistently related to higher serve velocities, and CMJ performance demonstrated a strong positive association with serve velocity. In the regression model, knee flexion peak torque of the dominant limb at 240°·s⁻¹ emerged as the only significant predictor of serve velocity, explaining a substantial proportion of its variance (R² = 0.797, p < 0.001). These findings indicate that serve velocity is closely associated with lower-extremity force production characteristics and highlight the importance of high-velocity knee flexor torque in explaining performance differences in elite junior tennis players.

Keywords

• Countermovement jump
• isokinetic strength
• lower-limb strength
• serve vellocity
• tennis

Supporting Institution

None

Project Number

2024/51

Ethical Statement

The study was approved by the Ordu University of Non-Interventional Scientific Research Ethics Committee (2024/51) and it was carried out in accordance with the Code of Ethics of the World Medical Association also known as a declaration of Helsinki.

Thanks

The authors would like to express their gratitude to the participants for their time and commitment.

References

1. Benjamini, Y., & Hochberg, Y. (1995). Controlling the false discovery rate: a practical and powerful approach to multiple testing. J R Stat Soc Series B Stat Methodol, 57(1), 289–300. doi: 10.1111/j.2517-6161.1995.tb02031.x
2. Bilić, Z., Martić, P., Barbaros, P., Sinković, F., & Novak, D. (2024). Neuromuscular fitness is associated with serve speed in young female tennis players. Sports (Basel), 12(4), 97. doi: 10.3390/SPORTS12040097
3. Bilić, Z., Očić, M., Dukarić, V., Petrinović, L., & Barbaros, P. (2025). Effects of physiological load on kinematic variables related to tennis serve performance. Sports (Basel), 13(7), 197. doi: 10.3390/SPORTS13070197
4. Borg, G. (1982). Psychophysical bases of perceived exertion. Med Sci Sports Exerc, 14(5), 377–381. doi: 10.5271/sjweh.1815
5. Brito, A. V., Fonseca, P., Costa, M. J., Cardoso, R., Santos, C. C., Fernandez-Fernandez, J., & Fernandes, R. J. (2024). The influence of kinematics on tennis serve speed: An in-depth analysis using Xsens MVN Biomech link technology. Bioengineering (Basel), 11(10), 971. doi: 10.3390/bioengineering11100971
6. Brocherie, F., & Dinu, D. (2022). Biomechanical estimation of tennis serve using inertial sensors: A case study. Front Sports Act Living, 4, 962941. doi: 10.3389/FSPOR.2022.962941/BIBTEX
7. Chapelle, L., Bishop, C., D’Hondt, J., Rommers, N., D’Hondt, E., & Clarys, P. (2023). Development of upper and lower extremity functional asymmetries in male and female elite youth tennis players: A longitudinal study. J Sports Med Phys Fitness, 63(12), 1269–1284. doi: 10.23736/S0022-4707.23.15043-2
8. Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.; J. Cohen, Ed.). New York: Lawrence Erlbaum Associates. Retrieved from https://utstat.utoronto.ca/brunner/oldclass/378f16/readings/CohenPower.pdf

9. Colomar, J., Corbi, F., Brich, Q., & Baiget, E. (2022). Determinant physical factors of tennis serve velocity: A brief review. Int J Sport Physiol, 17(8), 1159–1169. doi: 10.1123/IJSPP.2022-0091
10. Deng, N., Soh, K. G., Xu, F., & Yang, X. (2024). The effects of strength and conditioning interventions on serve speed in tennis players: A systematic review and meta-analysis. Front Physiol, 15. doi: 10.3389/FPHYS.2024.1469965
11. Dossena, F., Rossi, C., Latorre, A., & Bonato, M. (2018). The role of lower limbs during tennis serve. J Sports Med Phys Fitness, 58(3), 210–215. doi: 10.23736/S0022-4707.16.06685-8
12. Ganeva, M., Tsvetkova-Gaberska, M., Kanelov, I., & Pencheva, N. (2025). Time-based characteristics of knee extensors and flexors in young tennis players using Biodex system 4 isokinetic dynamometer. Int J Physiol Sports Phys Educ, 7(1), 35–38. doi: 10.33545/26647710.2025.V7.I1A.101
13. Girard, O., Mendez-Villanueva, A., & Bishop, D. (2011). Repeated-sprint ability - part I: Factors contributing to fatigue. Sports Med, 41(8), 673–694. doi: 10.2165/11590550-000000000-00000
14. Gorce, P., & Jacquier-Bret, J. (2024). Are there kinematic and kinetic parameters correlated with racket velocity during the tennis serve? A preliminary comparison between a slow and a fast serve for performance improvement. Front Sports Act Living, 6, 1451174. doi: 10.3389/FSPOR.2024.1451174
15. Hammami, N., Bouzouraa, E., Ölmez, C., Hattabi, S., Mhimdi, N., Khezami, M. A., … Jemni, M. (2024). Isokinetic knee strengthening impact on physical and functional performance, pain tolerance, and quality of life in overweight/obese women with patellofemoral pain syndrome. J Clin Med, 13(16), 4696. doi: 10.3390/jcm13164696
16. Hornestam, J. F., Souza, T. R., Magalhães, F. A., Begon, M., Santos, T. R. T., & Fonseca, S. T. (2021). The effects of knee flexion on tennis serve performance of intermediate level tennis players. Sensors (Basel), 21(16), 5254. doi: 10.3390/S21165254
17. İnal, S. (2013). Spor ve Egzersizde Vücut Biyomekaniği (2nd ed.). İstanbul: Papatya Publishing Education. (In Turkish)
18. Jacquier-Bret, J., & Gorce, P. (2024). Kinematics of the tennis serve using an optoelectronic motion capture system: Are there correlations between joint angles and racket velocity? Sensors (Basel), 24(11), 3292. doi: 10.3390/S24113292
19. Jr, J. F. H., Black, W. C., Babin, B. J., & Anderson, R. E. (2018). Multivariate Data Analysis. In https://eli.johogo.com/Class/CCU/SEM/_Multivariate%20Data%20Analysis_Hair.pdf?utm_source=chatgpt.com (8th ed.). Cengage.
20. Kaya, M., Soyal, M., & Karakuş, M. (2018). The effect of the leg and back strength of the serve and tennis players to the serve throwing speed and agility. Phys Educ Stud, 22(5), 237–242. doi: 10.15561/20755279.2018.0502
21. Koo, T. K., & Li, M. Y. (2016). A guideline of selecting and geporting intraclass correlation coefficients for reliability research. J Chiropr Med, 15(2), 155–163. doi: 10.1016/j.jcm.2016.02.012
22. Kovacs, M., & Ellenbecker, T. (2011). An 8-stage model for evaluating the tennis serve: Implications for performance enhancement and injury prevention. Sports Health, 3(6), 504–513. doi: 10.1177/1941738111414175
23. Kumar, S., Bairagi, K., Das, R., & Singh, M. (2024). Serve dynamics: Applying a bibliometric approach in the kinetics and kinematics analysis for flat and topspin serves in tennis. Phys Educ Theory Methodol, 24(5), 819–828. doi: 10.17309/TMFV.2024.5.18
24. Lambrich, J., & Muehlbauer, T. (2023). Biomechanical analyses of different serve and groundstroke techniques in tennis: A systematic scoping review. PLoS One, 18(8), e0290320. doi: 10.1371/JOURNAL.PONE.0290320
25. Lertwonghattakul, T., Sriramatr, S., & Rachnavy, P. (2023). Analysis of kinetic chain mechanism affecting energy flow in kick topspin tennis serve in elite and amateur tennis players. Ann Appl Sport Sci, 11(2), e1133. doi: 10.52547/AASSJOURNAL.1133
26. Liang, Z., Wu, J., Yu, J., Ying, S., Liu, Z., Zhang, Y., … Li, J. (2023). Comparison and analysis of the biomechanics of the lower limbs of female tennis players of different levels in foot-up serve. Front Physiol, 14, 1125240. doi: 10.3389/FPHYS.2023.1125240/BIBTEX
27. O’Brien, R. M. (2007). A caution regarding rules of thumb for variance inflation factors. Quality and Quantity, 41, 673–690. doi: 10.1007/s11135-006-9018-6
28. Ölmez, C., Hammami, N., Apaydın, N., Hattabi, S., Şar, H., Khezami, M. A., & İnce, A. (2025). Is isokinetic shoulder strength a determinant of serve ball velocity in tennis? Sports Biomech, 24(6), 1548–1561. doi: 10.1080/14763141.2023.2300315
29. Ölmez, C., Hammami, N., Yücelsoy, B., Hattabi, S., Forte, P., Sortwell, A., … İnce, A. (2023). Examining the link between isokinetic strength metrics and ball speed in women’s soccer. Appl Sci, 13(22). doi: 10.3390/APP132212217
30. Pan, J., Sun, D., Li, F., Zhou, Z., Wang, Y., Cen, X., … Fekete, G. (2025). The effects of skill level on lower-limb injury risk during the serve landing phase in male tennis players. Applied Sciences, 15(5), 2681. doi: 10.3390/app15052681
31. Perry, A. C., Wang, X., Feldman, B. B., Ruth, T., & Signorile, J. (2004). Can laboratory-based tennis profiles predict field tests of tennis performance? J Strength Cond Res, 18(1), 136–143. doi: 10.1519/00124278-200402000-00020
32. Rendos, N. K., Harriell, K., Qazi, S., Regis, R. C., Alipio, T. C., & Signorile, J. F. (2019). Variations in Verbal Encouragement Modify Isokinetic Performance. J Strength Cond Res, 33(3), 708–716. doi: 10.1519/JSC.0000000000002998
33. Robinson, C., & Schumacker, R. (2009). Interaction effects: Centering, variance inflation factor, and interpretation issues. Multiple Linear Regression Viewpoints, 35(1), 6-11.
34. Vacek, J., Vagner, M., Malecek, J., & Stastny, P. (2025). Tennis serve speed in relation to isokinetic shoulder strength, height, and segmental body mass in junior players. J Funct Morphol Kinesiol, 10(1), 57. doi: 10.3390/JFMK10010057
35. van Trigt, B., Faneker, E., Leenen, A. J. R., Hoekstra, A. E., & Hoozemans, M. J. M. (2024). Uncovering the hidden mechanics of upper body rotations in tennis serves using wearable sensors on Dutch professional players. Front Sports Act Living, 6, 1463299. doi: 10.3389/FSPOR.2024.1463299/BIBTEX
36. World Medical Association. (2013). World Medical Association Declaration of Helsinki: Ethical principles for medical research involving human subjects. JAMA, 310(20), 2191–2194. doi: 10.1001/JAMA.2013.281053