Affiliations: [a] Department of Physical Education & Sports Science,
Aristotelian University, Thessaloniki, Greece
Note: [] Address for correspondence: Christos Kotzamanidis, Department of
Physical Education & Sports Science, Aristotelian University Thessaloniki,
54006, Greece. Tel.: 0030310-992221; E-mail: kotzaman@phed.auth.gr
Abstract: The aim of the present study was to examine the concentric and
eccentric isokinetic moment of knee extensors in 108 boys aged 6 to 12 years
and in 15 young adults. Participants performed isokinetic concentric and
eccentric knee extensions at different angular velocities, 45°, 90° and
180°·s^{-1}. The Ancova designs, using lean mass
as covariate, revealed a significant age effect. Post hoc Scheffe test revealed
higher moment scores for adults compared to children. Statistical differences
between children were observed every two years. Eccentric moments were higher
than concentric moments at corresponding velocities. Concentric moments
decreased with increasing velocity whereas eccentric moments did not change
significantly. Boys were found to achieve almost 40% concentric and eccentric
moment of young adults at the age of 12 years. The higher annual increase of
both concentric and eccentric moment was observed at 7 years of age. The present data indicate a gradual and concurrent increase of
isokinetic concentric and eccentric moment with age from 6 to 12 years of age
suggesting probably a concurrent maturation of contractile and elastic
components of the muscle during childhood.
