, , ,
Volume 0, Issue 0 (11-2019)
Abstract
Introduction and Objective: One of the strategies that athletes can use to temporarily increase strength and muscle power is post-activation potentiation (PAP) during warm-up. However, the effect of this phenomenon on kinematics of special movement has not been determined. Therefore, the aim of this study is to investigate the acute effect of PAP during warm-up on lower extremity kinematic characteristics during heading in soccer players.
Methodology: The study sample consisted of 24 semi-professional youth soccer players with an average age of 18.67±1.11 years, height 182.32±7.12 cm, mass 74.17±7.46 kg. who performed four different warm-up methods, including PAP-take-off, PAP-landing, combined-PAP, and general warm-up, derived from the stages of soccer heading. Knee and hip angular velocities during the take-off phase, maximum knee flexion angle, and duration of knee joint pause during the landing phase were recorded using a three-dimensional motion analysis device (vicon peak ltd, oxford, vicon UK) with four T20 cameras with a frequency of 1000 Hz. Finally, analysis of variance with repeated measurements and post hoc Bonferroni test were used at a significance level of P<0.05.
Results: There was a significant increase in knee and hip angular velocities following combined-PAP and then PAP-take-off compared to other warm-up programs. Moreover, there was a significant increase in knee flexion angle after PAP-landing compared to other warm-up programs. Additionally, there was a significant increase in the duration of knee joint pause after general warm-up compared to other warm-up programs.
Discussion and Conclusion: PAP-take-off improves jumping performance, while PAP-landing improves landing performance. The combination of these two methods, i.e., combined-PAP, will yield better results overall.
Zahra Ghahremani, Hassan Daneshmandi, Mehrdad Anbarian,
Volume 21, Issue 26 (12-2023)
Abstract
The purpose of this study was to assess the acute effect of warm-up protocols (general and post-activation potentiation) on vertical jump performance and jump-landing technique in female handball players with trunk dysfunction. Twelve trained female handball players with trunk dysfunction participated voluntarily in this study. Subjects randomly performed three different warm-up protocols on separate days: 1- general warm-up protocol, 2- general warm-up with 2 repetitions of dynamic half-squat at %90 of one repetition maximum, 3- general warm-up with 2 repetitions of static half-squat at %90 of one repetition maximum. In the fifth minutes of recovery period after 3 protocols, subjects performed vertical jump and the Landing Error Scoring System tests, and Landing Error Scoring System scores, valgus and flexion angles, and vertical jump height was assessed. ANOVA with repeated measures was used for statistical data analysis. The jump height increased significantly after performing the second and third protocols related to general warm-up (p=0.039, p=0.047 respectively), but there weren’t a significant difference in Landing Error Scoring System score, valgus and flexion angles for three protocols. It seems that the special warm-up method by post-activation potentiation can improve vertical jump performance without influencing Anterior cruciate ligament injury risk.
