Banca de DEFESA: MATHEUS PEIXOTO DANTAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MATHEUS PEIXOTO DANTAS
DATE: 07/05/2021
TIME: 09:00
LOCAL: DEF
TITLE:

THE EFFECT OF REPEATED SPRINTS WITH A CHANGE OF DIRECTION IN THE ASYMMETRY AMONG AMERICAN FOOTBALL ATHLETES

KEY WORDS:

eywords: Asymmetry, Power, Injury risk, Fatigue.

PAGES: 50
BIG AREA: Ciências da Saúde
AREA: Educação Física
SUMMARY:

Introduction: Inter-limb asymmetry is commonly presenting on sports modalities and can be used for training load control and used for injury risk prediction. However, physical demand can influence on inter-limb asymmetry. Purpose: Thus, the aim of study is to verify the effect of the repeated-sprints protocol with change of direction on inter-limb asymmetry in American football athletes. Methods: Ten American football athletes were recruited for participation on quasi-experimental study. In first day, the participants realized a warm-up and the were for physical evaluation. The sprint with change of direction and countermovement jump were performed. The single-leg countermovement jump (SLCMJ) was realized according to preference limb. SLCMJ was performed alternately between limbs, three jumps with each limb. The limb with the best performance was used as a dominant limb. The extensors (PTE) and flexors (PTF) peak torque was evaluated from isokinetic concentric contraction with 60º/s of velocity. SLCMJ, PTE and PTF asymmetry was calculated by percentual difference between measures. Results: Dominant limb (DL) has higher performance extensors peak torque than non-dominant limb (NDL) during no-fatigue (NFAT) (∆= 18.26, 95%CI= 2.76 to 33.76, p= 0.026), but no during fatigue (FAT) (∆= 8.78, 95%CI= -4.78 to 22.35, p= 0.177). PTF has no fatigue (F_(1,9)= 1.72, p= 0.222, η²= 0.161), limbs (F_(1,9)= 0.27, p= 0.613, η²= 0.030) and interaction effect (F_(1,9)= 1.57, p= 0.242, η²= 0.149). PTE asymmetry no has statistical difference post-fatigue (t₍₉₎= 1.46; p= 0.178; ∆= 4.97, 95%CI= -2.73 to 12.67; r= 0.424; p= 0.222), as PTF (t₍₉₎= -1.18; p= 0.266; ∆= -8.12, 95%CI= -23.61 to 7.37; r= 0.585; p= 0.076). DL has higher SLCMJ performance than NDL during NFAT (∆= 1.34, 95%CI= 0.60 to 2.08, p= 0.003), but not during FAT (∆= 1.29, 95%CI= -0.32 to 2.90, p= 0.104). SLCMJ asymmetry no has statistical difference on NFAT and FAT means, besides not correlation (t₍₉₎= -0.88; p= 0.402; ∆= -2.92, 95%CI= -10.43 to 4.58; r= 0.109; p= 0.765). Only SLCMJ asymmetry data show variance homogeneity (F= 0.87, p= 0.581). SLCMJ asymmetry (ICC= -0.15, 95%CI= -0,63 to 0,71), PTE asymmetry (ICC= 0.59; 95%CI= -0.63 to 0.90) and PTF asymmetry (ICC= 0.69; 95%CI= -0.25 to 0.92) do not have reproducibility in NFAT and FAT. Conclusion: The repeated-sprint with change of direction protocol can be promote a heterogeneous response on lower-limbs strength asymmetry in American football athletes. It has been demonstrated that asymmetries assessed under baseline conditions do not agree with assessment under fatigue condition.

BANKING MEMBERS:
Presidente - 2627140 - BRENO GUILHERME DE ARAUJO TINOCO CABRAL
Interno - 1793257 - ARNALDO LUIS MORTATTI
Interno - 2626634 - PAULO MOREIRA SILVA DANTAS
Externo à Instituição - FABIO YUZO NAKAMURA - UFPB
Externo à Instituição - FELIPE JOSÉ AIDAR MARTINS - UFS