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Effect of orthoses on changes in neuromuscular control and aerobic cost of a 1-h run

Kelly, L.A., Girard, O. and Racinais, S. (2011) Effect of orthoses on changes in neuromuscular control and aerobic cost of a 1-h run. Medicine & Science in Sports & Exercise, 43 (12). pp. 2335-2343.

Link to Published Version: https://doi.org/10.1249/MSS.0b013e31822037ca
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Abstract

Purpose: The study’s purpose was to determine the effect of foot orthoses on neuromuscular control and the aerobic cost of running.

Methods: Twelve recreational athletes ran for 1 h on a treadmill at a constant velocity (i.e., 10% higher than their first ventilatory threshold) with and without custom-molded foot orthoses, in a counterbalanced order. Surface EMG activity of five lower limb muscles, together with oxygen consumption and HR, was recorded at 8-min intervals, starting after 2 min, during the run. A series of neuromuscular tests including voluntary and electrically evoked contractions of the ankle plantar flexors was performed before and after running.

Results: Peroneus longus root mean square amplitude decreased with time, independently of the condition (−18.9%, P < 0.01). Lower root mean square signal amplitude for vastus medialis (−13.3%, P < 0.02) and gastrocnemius medialis (−10.7%, P < 0.05), combined with increased peroneus longus burst duration (+14.7%, P < 0.05), occurred when running with orthoses. There was no main effect of the condition for oxygen consumption (P > 0.05), whereas HR was significantly lowered while wearing foot orthoses (−3%, P < 0.02). Maximal strength capacity (−9%, P < 0.01), normalized EMG activity (−17%, P < 0.001), and peak twitch torque (−14%, P < 0.01) declined from before to after exercise, independently of the condition. Smaller fatigue-induced decrements in the rate of torque development within the first 200 ms (−6% vs −33%, P < 0.01) were reported after running with foot orthoses.

Conclusions: Wearing foot orthoses alters neuromuscular control during a submaximal 1-h treadmill run and partly protects from the resulting fatigue-induced reductions in rapid force development characteristics of the plantar flexors. However, these changes may be too small to alter the aerobic cost of running.

Item Type: Journal Article
Publisher: Lippincott Williams & Wilkins
Copyright: © 2011 The American College of Sports Medicine
URI: http://researchrepository.murdoch.edu.au/id/eprint/45934
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