Influence of hip-flexion angle on hamstrings isokinetic activity in sprinters.

Détails

ID Serval
serval:BIB_52346890C700
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Influence of hip-flexion angle on hamstrings isokinetic activity in sprinters.
Périodique
Journal of Athletic Training
Auteur(s)
Guex K., Gojanovic B., Millet G.P.
ISSN
1938-162X (Electronic)
ISSN-L
1062-6050
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
47
Numéro
4
Pages
390-395
Langue
anglais
Notes
Publication types: Journal ArticlePublication Status: ppublish
Résumé
CONTEXT: Hamstrings strains are common and debilitating injuries in many sports. Most hamstrings exercises are performed at an inadequately low hip-flexion angle because this angle surpasses 70° at the end of the sprinting leg's swing phase, when most injuries occur.
OBJECTIVE: To evaluate the influence of various hip-flexion angles on peak torques of knee flexors in isometric, concentric, and eccentric contractions and on the hamstrings-to-quadriceps ratio.
DESIGN: Descriptive laboratory study.
SETTING: Research laboratory. Patients and Other Participants: Ten national-level sprinters (5 men, 5 women; age = 21.2 ± 3.6 years, height = 175 ± 6 cm, mass = 63.8 ± 9.9 kg). Intervention(s): For each hip position (0°, 30°, 60°, and 90° of flexion), participants used the right leg to perform (1) 5 seconds of maximal isometric hamstrings contraction at 45° of knee flexion, (2) 5 maximal concentric knee flexion-extensions at 60° per second, (3) 5 maximal eccentric knee flexion-extensions at 60° per second, and (4) 5 maximal eccentric knee flexionextensions at 150° per second. Main Outcome Measure(s): Hamstrings and quadriceps peak torque, hamstrings-to-quadriceps ratio, lateral and medial hamstrings root mean square.
RESULTS: We found no difference in quadriceps peak torque for any condition across all hip-flexion angles, whereas hamstrings peak torque was lower at 0° of hip flexion than at any other angle (P < .001) and greater at 90° of hip flexion than at 30° and 60° (P < .05), especially in eccentric conditions. As hip flexion increased, the hamstrings-to-quadriceps ratio increased. No difference in lateral or medial hamstrings root mean square was found for any condition across all hip-flexion angles (P > .05).
CONCLUSIONS: Hip-flexion angle influenced hamstrings peak torque in all muscular contraction types; as hip flexion increased, hamstrings peak torque increased. Researchers should investigate further whether an eccentric resistance training program at sprint-specific hip-flexion angles (70° to 80°) could help prevent hamstrings injuries in sprinters. Moreover, hamstrings-to-quadriceps ratio assessment should be standardized at 80° of hip flexion.
Pubmed
Web of science
Création de la notice
17/08/2012 14:05
Dernière modification de la notice
03/03/2018 17:12
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