Validity and reliability of a microcontroller-based instrument for measuring karate punch speed and power
DOI:
https://doi.org/10.47197/retos.v80.119326Keywords:
Validity, reliability, punch speed, punch power, karate, microcontrollerAbstract
Introduction: Objective, field-ready instruments are needed in karate because punch performance depends on both speed and power. In practice, punch evaluation relies on coach observation, which supports technical feedback but is limited in producing repeatable measurement data. Few studies have examined devices designed for karate punching.
Objective: This study examined the validity and reliability of a microcontroller-based instrument for measuring karate punch speed and power.
Results: The study used a research and development approach involving expert validation, a small-group trial with 10 karate athletes, and a large-group trial with 20 athletes from FORKI Palembang, Indonesia. Expert judgment showed feasibility, with scores of 93% from the karate coaching expert, 92% from the karate refereeing expert, and 90% from the mechatronics and sensor expert, producing an average score of 91%. Normality was examined using the Kolmogorov-Smirnov test, with significance values of .498 for speed and .800 for power. Pearson analysis showed a strong inverse association between speed and power outputs (r = -.972, p < .001), interpreted as preliminary empirical coherence rather than standalone validity evidence. Test-retest results indicated stable scores, with corrected item-total correlation values ranging from .994 to .999 and Cronbach’s alpha if item deleted values ranging from .997 to .999.
Discussion: These findings indicate that the instrument can provide stable measurements of karate punch performance in applied settings, although future criterion-related validation against biomechanical systems is needed.
Conclusions: The instrument appears feasible, reliable, and promising for training evaluation and athlete monitoring, provided future studies strengthen criterion-related validation and sensor refinement.
References
Almanasreh, Enas, Rebekah Moles, and Timothy F. Chen. 2019. “Evaluation of Methods Used for Estimating Content Validity.” Research in Social and Administrative Pharmacy 15(2):214–21. doi:10.1016/j.sapharm.2018.03.066.
Alonso-Hernán, Daniel, and Monica Gomez-Suarez. 2026. “Escala de Expresividad Identitaria En Aficio-nados de Fútbol: Validación y Aplicaciones Para La Gestión Deportiva.” Retos 80:193–205. doi:10.47197/retos.v80.118559.
Budijono, Agung Prijo, Pradini Puspitaningayu, Wahyu Dwi Kurniawan, Awang Firmansyah, Novadri Ayubi, Kritchapol Arsapakdee, and Andika Bayu Putro. 2024. “Considering the Validity and Relia-bility Testing of a Digital Punch Measuring Tool in Young Combat Athletes.” Physical Education Theory and Methodology 24(5):683–88. doi:10.17309/tmfv.2024.5.01.
Gosselin, Romain-Daniel. 2024. “Testing for Normality: A User’s (Cautionary) Guide.” Laboratory Ani-mals 58(5):433–37. doi:10.1177/00236772241276808.
Irianto, Subagyo, Tomoliyus Tomoliyus, Awan Hariono, Yulvia Miftachurochmah, and Hary Widodo. 2025. “Development of Junior Football Skills Test Based on Validity and Reliability through Ex-pert Judgment.” Retos 70:493–504. doi:10.47197/retos.v70.111188.
López-Pina, Jose-Antonio, and Alejandro Veas. 2024. “Validation of Psychometric Instrumentswith Classical Test Theory in Social and Health Sciences: A Practical Guide.” Anales de Psicología 40(1):163–70. doi:10.6018/analesps.583991.
Mamani-Ramos, Angel Anibal, Edgar Froilan Damian-Nuñez, Edgar Eloy Carpio-Vargas, Jorge Alber Quisocala-Ramos, Carlos Wyly Dextre-Mendoza, Xavier Fuentes-Avila, Kandy Faviola Tuero-Chirinos, Naysha Sharon Villanueva-Alvaro, Carlos Vidal Cutimbo-Quispe, and Jhony Ruben Ro-driguez-Mamani. 2025. “Cuestionario Sobre Apoyo Familiar En La Actividad Física Para Adoles-centes (CAFAFA): Validez y Fiabilidad de Una Nueva Propuesta.” Retos 70:317–30. doi:10.47197/retos.v70.115153.
Mestre Moron, Beatriz Elena, Everardo Manuel Sanchez Puche, Gabriel Fernando Franco Maya, Edelber-to R. Redondo Reynoso, and José Mauricio Rivero Olmos. 2026. “Cinética y Perfil Del Lactato En Karatecas Universitarios: Comparación Entre Protocolos Incremental y Mínimo.” Retos 76:544–53. doi:10.47197/retos.v76.117680.
Nurfauzan, Prayogi, Guntur Guntur, Aris Fajar Pambudi, Ade Gusti Ningsih, Apriliana Nurulita Nur Fauzi, Andika Triansyah, Fatma Atik Mulyani, St. Nur Almaidah RS., Atina Atina, Maria Magdalena Sri Wahyuni, Arief Kuswidyanarko, Irene Maria Wato, Anna Mariyani, Hidayatul Hikmah, and Am-ran Amran. 2025. “Development and Validation of a Quantum Learning Model Based on Tradi-tional Games to Improve Physical Literacy in Primary School Students.” Retos 69:1401–18. doi:10.47197/retos.v69.116823.
Omcirk, Dan, Tomas Vetrovsky, Jan Padecky, Jan Malecek, and James J. Tufano. 2023. “Validity of Com-mercially Available Punch Trackers.” Journal of Strength & Conditioning Research 37(11):2273–81. doi:10.1519/JSC.0000000000004535.
Pezenka, Lukas, and Klaus Wirth. 2025. “Reliability of a Low-Cost Inertial Measurement Unit (IMU) to Measure Punch and Kick Velocity.” Sensors 25(2):307. doi:10.3390/s25020307.
Qi, Ji, Rangxi Jin, Tongling Wang, Zengyi Li, Mitchell James Finlay, and Chao Chen. 2026. “Reliability and Validity of the ‘XingXun’ System for Measuring Punch Acceleration and Velocity in Elite Boxers.” Frontiers in Physiology 17. doi:10.3389/fphys.2026.1726442.
Quinzi, Federico, Gioele Rosellini, and Paola Sbriccoli. 2022. “Lower Limb Maximal Power Predicts Punching Speed in Different Static and Dynamic Attacking Techniques in Karate.” Journal of Strength & Conditioning Research 36(5):1353–59. doi:10.1519/JSC.0000000000003653.
Ranganathan, Priya, Carlo Caduff, and Christopher M. A. Frampton. 2024. “Designing and Validating a Research Questionnaire - Part 2.” Perspectives in Clinical Research 15(1):42–45. doi:10.4103/picr.picr_318_23.
Rhayha, Radouane, and Abderrahman Alaoui Ismaili. 2024. “Development and Validation of an Instru-ment to Evaluate the Perspective of Using the Electronic Health Record in a Hospital Setting.” BMC Medical Informatics and Decision Making 24(1):291. doi:10.1186/s12911-024-02675-0.
Ríder-Vázquez, Antonio, Estanislao Gutiérrez-Sánchez, Clara Martinez-Perez, and María Sánchez-González. 2025. “Test–Retest Reliability of a Computerized Hand–Eye Coordination Task.” Jour-nal of Eye Movement Research 18(5):54. doi:10.3390/jemr18050054.
Robalino, Johan, João Paulo Vilas-Boas, Emerson Franchini, Antonio Roberto Bendillati, Mauro Gonçal-ves, and Márcio Fagundes Goethel. 2025. “Kinetic Chain Contribution to Speed and Energy in Ka-rate Techniques.” Applied Sciences 15(17):9726. doi:10.3390/app15179726.
Robertson, S., J. Zendler, K. De Mey, J. Haycraft, G. I. Ash, C. Brockett, D. Seshadri, C. Woods, L. Kober, R. Aughey, and J. Rogowski. 2023. “Development of a Sports Technology Quality Framework.” Journal of Sports Sciences 41(22):1983–93. doi:10.1080/02640414.2024.2308435.
Robinson, John. 2023. “Likert Scale.” Pp. 3917–18 in Encyclopedia of Quality of Life and Well-Being Research. Cham: Springer International Publishing.
Xue, Hongyu, Chaoran Han, and Dinghuang Zhu. 2025. “Limb Biomechanics in Combat Sports: Insights from Wearable Sensor Technology.” Frontiers in Bioengineering and Biotechnology 13. doi:10.3389/fbioe.2025.1663592.
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