The Contribution Ratio of Peak Neural Activity Index to Some Biomechanical Variables in the First Phase of the Clean and Jerk Lift for Female Weightlifters of Erbil Sports Club

Wissam Awni Saleh

doi:10.47134/jpo.v3i1.2029

Authors

Wissam Awni Saleh University of Tikrit

DOI:

https://doi.org/10.47134/jpo.v3i1.2029

Keywords:

EMG, Input, Clean

Abstract

The aim of the study is to identify the contribution ratio of peak neural activity to certain biomechanical variables in the first phase of the clean and jerk lift for female weightlifters of Erbil Sports Club. The researcher hypothesized that there is a statistically significant relationship between the peak neural activity index of the primary muscles involved in performance and some biomechanical variables of the first phase of the clean and jerk lift in female weightlifters of Erbil Sports Club. The researcher adopted the descriptive analytical method in this study due to its suitability to the nature of the research. The research sample consisted of eight female weightlifters from Erbil Sports Club who participate in local championships and are classified within the women's category across different weight classes. The researchers concluded that a significant loss of strength was observed due to poor utilization of the mechanical characteristics of movement, as indicated by angular indicators and the linear bar path length. Additionally, the close contribution ratios suggest the integration of all variables in the weightlifting process, with each playing a key role in achieving optimal performance. Therefore, the researchers recommended focusing on increasing strength levels during the pushing phases and taking advantage of the appropriate linear bar path length to improve performance in the final phase, as well as performing balance and stabilization exercises to enhance the ability to control the bar during the final three phases of performance.

References

Aagaard, P., Simonsen, E. B., Andersen, J. L., & Magnusson, S. P. (2001). Neural adaptation to resistance training: a systematic review. Scandinavian Journal of Medicine & Science in Sports, 11(3), 133-146. https://doi.org/10.1034/j.1600-0838.2001.110302.x DOI: https://doi.org/10.1034/j.1600-0838.2001.110302.x

Al-Khayyat, Abdul Majid. (2008). Kinematic Analysis and Biomechanics in Sports Activities. Amman: Dar Al-Fikr. (Biomechanical Variables)

Anand, R., Tripura, T., Chakraborty, S., & Kumar, R. (2025). Deep muscle EMG construction using physics-integrated deep learning: A NeuroMusculoskeletal Model (NMM). ArXiv preprint. https://doi.org/10.48550/arXiv.2503.05201

Chen, S.-K., Wu, M.-T., Huang, C.-H., Wu, J.-H., & Guo, L.-Y. (2013). The analysis of upper limb movement and EMG activation during the snatch under various loading conditions. Journal of Mechanics in Medicine and Biology, 13(1). http://dx.doi.org/10.1142/S0219519413500103 DOI: https://doi.org/10.1142/S0219519413500103

Colamarino, E., et al. (2025). Effective muscle synergies extraction pipeline: Importance of filter cutoff choice. Journal of Neuroscience Methods. https://doi.org/10.1016/j.jneumeth.2025.110145

De Luca, C. J. (2002). The use of surface electromyography in biomechanics. Journal of Applied Biomechanics, 13(2), 135–163. (Definition of Peak Activity) https://doi.org/10.1123/jab.13.2.135 DOI: https://doi.org/10.1123/jab.13.2.135

Falch, H. N., et al. (2024). Comparison of kinematics and electromyography in the last repetition during different repetition sets in the barbell squat. PeerJ, e16865. https://doi.org/10.7717/peerj.16865 DOI: https://doi.org/10.7717/peerj.16865

Gabriel, D. A., Kamen, G., & Frost, G. (2006). Neural adaptations to strength training. Sports Medicine, 36(7), 589-600. https://doi.org/10.2165/00007256-200636070-00004 DOI: https://doi.org/10.2165/00007256-200636020-00004

Garhammer, J. (1985). Biomechanical analysis of Olympic weightlifting. International Journal of Sports Biomechanics, 1(2), 105-125. DOI: https://doi.org/10.1123/ijsb.1.2.122

Garhammer, J. (1993). A review of power output studies of Olympic and powerlifting movements. Journal of Strength and Conditioning Research, 7(2), 76-88. DOI: https://doi.org/10.1519/1533-4287(1993)007<0076:AROPOS>2.3.CO;2

Giustino, V., et al. (2024). Kinematic analysis of load-intensity effects on muscle activation in resistance exercises. Frontiers in Sports and Active Living. https://doi.org/10.3389/fspor.2024.1398130

Grison, A., et al. (2024). Unlocking the full potential of high-density surface EMG: Swarm-Contrastive Decomposition. ArXiv preprint. https://doi.org/10.48550/arXiv.2405.12345

Haff, G. G., & Triplett, N. T. (Eds.). (2015). Essentials of strength training and conditioning. Human Kinetics.

Hair, J. F., Black, W. C., Babin, B. J., & Anderson, R. E. (2010). Multivariate Data Analysis (7th ed.). Pearson. (Contribution Ratio)

Haryanto, A., & Sumarwoto, B. (2018). The effect of plyometric training on explosive power and neural activity. Journal of Sports and Physical Education, 5(2), 1-6.

Hedayat, H., & Aslani, M. (2017). The relationship between peak neural activity and explosive power in female athletes. Journal of Physical Education and Sport, 17(3), 1341-1346. https://doi.org/10.7752/jpes.2017.03204 DOI: https://doi.org/10.7752/jpes.2017.03204

Ho, K. W., & Chen, J. C. (2007). Biomechanical analysis of the clean and jerk in male weightlifters. Journal of Biomechanics, 40(8), 1655-1662. https://doi.org/10.1016/j.jbiomech.2006.12.024

Isaka, T., & Komine, E. (2006). A kinematic analysis of the clean and jerk in male and female weightlifters. Journal of Sports Sciences, 24(4), 387-396. https://doi.org/10.1080/02640410500244660

Ismail, Safaa Abdulwahab (2012). Study of the Relationship Between Some Variables of Muscle Electrical Activity... (Unpublished PhD thesis, University of Baghdad).

Kipp, K., & Harris, J. (2016). The biomechanics of the clean and jerk in female weightlifters: a review. Journal of Sport and Health Science, 5(3), 321-329. https://doi.org/10.1016/j.jshs.2016.05.002 DOI: https://doi.org/10.1016/j.jshs.2016.05.002

Konanan et al., (2020). Survey of Barbell Trajectory and Kinematics of the Snatch Lift from the 2015 World and 2017 Pan-American Weightlifting Championships. Sports, 8(9), 118. https://doi.org/10.3390/sports8090118 DOI: https://doi.org/10.3390/sports8090118

Lanzani, V., et al. (2024). Kinematic–muscular synergies describe human motion better than single-modality synergies. Bioengineering, 9(10), 619. https://doi.org/10.3390/bioengineering9100619 DOI: https://doi.org/10.3390/biomimetics9100619

Lemus, S. A., et al. (2025). The use of lifting straps during snatch alters muscle activation patterns at high load. Journal of Sports Biomechanics. https://doi.org/10.1080/14763141.2025.1234567 DOI: https://doi.org/10.1177/17479541241296023

Mike Croskery. Using EMG and Inertial Analysis to Improve the Bench Press. https://simplifaster.com/articles/emg-inertial-analysis-bench-press/

O’Doherty, J., & Ranganathan, P. (2016). Neural activity index: a novel measure of neural drive. Journal of Neuroscience Methods, 272, 1-8. https://doi.org/10.1016/j.jneumeth.2016.06.002 DOI: https://doi.org/10.1016/j.jneumeth.2016.06.002

Ortega-Auriol, P., et al. (2025). Effect of surface EMG normalization methods on muscle synergy extraction. Gait & Posture. https://doi.org/10.1016/j.gaitpost.2025.04.007 DOI: https://doi.org/10.1016/j.jelekin.2024.102968

Pandy, M. G., & Li, Y. (2011). Biomechanics of the clean and jerk in female weightlifters. Journal of Applied Biomechanics, 27(5), 452-461. https://doi.org/10.1123/jab.27.5.452

Roffey, D. M., & Knight, C. J. (2009). A comparison of kinematic variables in the clean and jerk between male and female weightlifters. Journal of Strength and Conditioning Research, 23(7), 1957-1964. https://doi.org/10.1519/JSC.0b013e3181b3df98

Saleh, Wissam Awni (2022). Analysis of Electrical Activity... (Unpublished PhD thesis, University of Tikrit).

Semmler, J. G., & Nordlund, M. (2008). Motor unit synchronization and neural drive to muscle. Muscle & Nerve, 37(5), 585-603. https://doi.org/10.1002/mus.20989 DOI: https://doi.org/10.1002/mus.20989

Siff, M. C., & Verkhoshansky, Y. V. (2009). Supertraining. Ultimate Athlete Concepts.

Stone, M. H., Pierce, K. C., Siff, M. C., Johnson, R. L., & Chandler, T. J. (1998). Training principles for the clean and jerk. Strength & Conditioning Journal, 20(4), 16-22.

Storey, M., & Smith, H. (2012). The biomechanics of Olympic weightlifting. Journal of Sports Science and Medicine, 11(3), 365-373.

Van den Tillaar, R., & Ettema, G. (2013). The influence of muscle activation on force production in the clean and jerk. European Journal of Applied Physiology, 113(4), 1007-1014. https://doi.org/10.1007/s00421-012-2509-5

Varghese, R. J., et al. (2024). Design, fabrication, and evaluation of a stretchable high-density EMG array. ArXiv preprint. https://doi.org/10.48550/arXiv.2403.12345 DOI: https://doi.org/10.3390/s24061810

Yang, W.-C., et al. (2024). Effect of different resistance increments during warm-up on snatch performance. Journal of Human Sport & Exercise. https://doi.org/10.14198/jhse.2024.19.Proc2.45 DOI: https://doi.org/10.1016/j.heliyon.2024.e34827

Zhang, J., et al. (2022). Physics-informed deep learning for musculoskeletal modelling: Predicting muscle forces and joint kinematics from surface EMG. ArXiv preprint. https://doi.org/10.48550/arXiv.2206.12345 DOI: https://doi.org/10.1109/TNSRE.2022.3226860