Neural control of leg stiffness during hopping in boys and men
Smith, Paul M.
MetadataShow full item record
The purpose of the study was to investigate whether boys and men utilise different control strategies whilst hopping. Eleven boys (11–12 yr old) and ten men completed hopping at 1.5 Hz, 3.0 Hz and at their preferred frequency. A footswitch measured contact and flight times, from which leg stiffness was calculated. Simultaneously, surface electromyograms (EMGs) of selected lower limb muscles were recorded and quantified for each 30 ms period during the first 120 ms post-ground contact. At 1.5 Hz there were no differences between the groups in relative stiffness or muscle activity. At 3.0 Hz men had significantly shorter contact times (P = 0.013), longer flight times (P = 0.002), greater relative stiffness (P = 0.01) and significantly greater soleus (P = 0.012) and vastus lateralis (P < 0.001) activity during the initial 30 ms post-ground contact. At the preferred frequency men hopped significantly faster than the boys (P = 0.007), with greater leg stiffness (P < 0.01) and with more extensor activity in most time periods. Boys and men demonstrated similar control strategies when hopping at a slow frequency, but when hopping frequency increased men were able to better increase feedforward and reflex muscle activity to hop with greater relative stiffness. © Elsevier Ltd. All rights reserved.
Journal of Electromyography and Kinesiology
Oliver, J.L. and Smith, P.M. (2010) 'Neural control of leg stiffness during hopping in boys and men', Journal of Electromyography and Kinesiology, 20(5), pp.973-979.
This article was published in Journal of Electromyography and Kinesiology in October 2010, available at http://dx.doi.org/10.1016/j.jelekin.2010.03.011
- Sport Research Groups 
Showing items related by title, author, subject and abstract.
Lloyd, Rhodri S. (University of Wales, 2011)The stretch-shortening cycle (SSC) is an intricate muscle action, which is fundamental to successful plyometric performance. However, there currently exists minimal research examining the effects of age, maturation and ...
Investigation into the Relationship between Cardiorespiratory Fitness, Physical Activity, and Arterial Stiffness Hibbard, Andrew (University of Wales Institute Cardiff, 2012)Introduction Arterial compliance plays an important role in cardiovascular disease morbidity (CVD) and mortality. Two important risk factors identified as determinants of arterial stiffness involve low physical activity ...
Oliver, Jon; De Ste Croix, M. B. A.; Lloyd, Rhodri S.; Williams, Craig A. (Springer, 2014)Abstract Purpose To examine changes to neuromuscular control of leg stiffness following 42 min of soccer-specific exercise. Methods Ten youth soccer players, aged 15.8 ± 0.4 years, stature 1.73 ± 0.06 m and ...