Velocity-specific knee strength between professional and under-17 female volleyball players

• Published in: The South African journal of physiotherapy Vol. 75; no. 1; pp. 1 - 7
• Main Authors: Dela Bela, Laís F., Brown, Lee E., Rodrigues, Lucas C.R., Batista Jr, João P., Moura, Felipe A., Carregaro, Rodrigo L., Guenka, Leandro C., Cardoso, Jefferson R., Pelegrinelli, Alexandre R.M., Dias, Josilainne M., Silva, Mariana F.
• Format: Journal Article
• Language: English
• Published: South Africa AOSIS 2019; African Online Scientific Information Systems (Pty) Ltd t/a AOSIS
• Subjects: Dynamometer; Health aspects; Knee; Muscle strength; Original Research; Risk factors; Sports; Sports injuries; Volleyball; Volleyball players; Weight training; muscle strength; knee; dynamometer; volleyball; sports
• ISSN: 0379-6175; 2410-8219
• DOI: 10.4102/sajp.v75i1.478

Background: Many studies have investigated isokinetic performance in volleyball players but not through surface maps.Objectives: The goals of this study were to assess velocity-specific isokinetic knee extensor–flexor muscle strength and to compare the isokinetic knee extensor–flexor muscles between professional (PRO) and under-17 (U17) female volleyball players.Method: This cross-sectional laboratory study was developed with two groups: PRO (n = 12), medianage = 21.3 years, and U17 (n = 9), medianage = 15 years. Peak torque, total work, mean power, angle of peak torque, hamstring–quadriceps torque ratio (H–Q ratio) and torque–angle–velocity surface maps were analysed from knee extension–flexion at 60, 120 and 300 degrees per second (°/s).Results: Significant differences were identified for extensor peak torque between PRO x = 202.3 Newton metre (N·m) (standard deviation [SD] = 24.4) and U17 x = 141.6 N·m (30.1) at 60 °/s (p Conclusion: Different groups of female volleyball players showed contrasting concentric knee muscle strength across isokinetic velocities.Clinical implications: These results demonstrate the importance of specific strength training for different age groups, even within the same sport, and provide insight into muscle strength.