title: The acute effects of an intense stretch-shortening cycle fatigue protocol on the neuromechanical parameters of lower limbs in men and prepubescent boys.
abstract: The study examined the differences between boys and adults after an intense stretch-shortening cycle fatigue protocol on neuromechanical parameters of the lower limb. Thirteen boys (9-11 years old) and 13 adult men (22-28 years old) were tested for maximal isometric voluntary knee extension torque and drop jump (DJ) performance from 30 cm before and immediately after a fatigue protocol, consisted of 10 × 10 maximum effort vertical jumps. Three-dimensional kinematics, kinetics and electromyographic (EMG) parameters of the lower extremities muscles were recorded during DJs before and after the fatigue test. The results indicated that reduction in maximal isometric torque and jumping performance was significantly higher in adults compared to boys. Vertical ground reaction forces, contact time and maximum knee flexion increased in a greater extend in adults than in boys. In addition, preactivation, EMG agonist activity, knee joint stiffness and stretch reflex decreased more in adults than in boys at all the examined phases of jumping tasks. It is concluded that employed fatigue protocol induced acute reduction in performance and altered motor control during jumping in both age groups. However, the differences in the level of fatigue between the 2 groups could be attributed to neuromuscular, mechanical and kinematic parameters observed between groups.
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Savvas
authors.initials: S
authors.lastname: Lazaridis
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Dimitrios A
authors.identifier: http://orcid.org/0000-0001-8921-4176
authors.initials: DA
authors.lastname: Patikas
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Bassa
authors.affiliation: b Center for Research and Technology , Institute for Research and Technology Thessaly , Trikala , Greece.|c School of Physical Education and Sport Science , University of Thessaly , Trikala , Greece.
authors.forename: Themistoklis
authors.initials: T
authors.lastname: Tsatalas
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Konstantinos
authors.identifier: http://orcid.org/0000-0002-4699-3672
authors.initials: K
authors.lastname: Hatzikotoulas
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Ftikas
authors.affiliation: a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Kotzamanidis
mesh_terms: D000328:Adult; D000367:Age Factors; D001696:Biomechanical Phenomena; D002648:Child; D004576:Electromyography; D006801:Humans; D007700:Kinetics; D035002:Lower Extremity / Q000294:innervation / Q000502:physiology*; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D059385:Plyometric Exercise; D055815:Young Adult
keywords: Neuromuscular; childhood; exercise; jump; kinematics