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Effects of perturbation training on quadriceps and hamstring electromyographic ratios
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| Amir Letafatkar *, Reza Rajabi, Esmaeil Ebrahimi Tekamejani, Hooman Minoonejad |
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Abstract: (7399 Views) |
| Introduction: It seems knee joint stability through co-contraction (CC) of hamstrings
and quadriceps may be necessary for athletes with quadriceps dominance (QD)
neuromuscular deficit. The lower CC and muscle activity ratio in medial
compartment of knee can predispose this joint to excessive valgus position that
exaggerates anterior cruciate ligament (ACL) injury. The purpose of this study
was to determine the effects of perturbation training on quadriceps and
hamstring ratios in QD deficit athletes. Materials and Methods: EMG data of quadriceps and hamstrings (during single limb drop landing) of
53 (26 control and 27 experimental) athletes with quadriceps dominance deficit
(identified with tuck jump test) acquired in pre-test and post-test. After completing
6 weeks of perturbation training in experimental group, the repeated-measures
analyses of variance, independent sample t-test and paired sample t tests used
for statistical analysis. Results: After perturbation training, the lateral knee compartment
CC decreased and medial knee compartment CC increased (both in feed-forward and
feedback phases). The medial to lateral knee compartment ration increased after
six weeks of perturbation training. Also in the post test, the higher effect
size observed in studied variables. Conclusion: Improvement in CC in knee
medial compartment can limit the knee valgus and also anterior shear force that
led to ACL optimal control. Considering the extremely large effect size of the
perturbation group, we recommend that this program be used in the correction of
QD deficit women in future |
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| Keywords: Anterior cruciate ligament injury, Quadriceps muscle, Exercise therapy methods, Muscle contraction, Knee joint, Electromyography |
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Full-Text [PDF 247 kb]
(1732 Downloads)
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Type of Study: Research |
Subject:
General
Received: 2013/09/6 | Accepted: 2014/06/11 | Published: 2014/06/11
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