The impact of altered task mechanics on timing and duration of eccentric bi-articular muscle contractions during cycling

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

External organisations

  • School of Human Movement Studies, University of Queensland, Brisbane

Abstract

In order to understand muscle adaptations to altered task mechanics during cycling, this study investigated the impact of altered seat height and cadence on timing and duration of gastrocnemius (GAST), biceps femoris (BF) and vastus lateralis (VL) eccentric contractions and muscle activation patterns, and cycling economy. Ten male cyclists completed 9 × 5 min of cycling at 3 seat heights and 3 cadences. Three-dimensional leg kinematics and muscle activation patterns were recorded to estimate timing of eccentric muscle contractions. Onset, offset and duration of eccentric contractions and, onset, offset and duration of muscle activation were calculated, along with cycling economy. Duration of GAST and VL eccentric contractions decreased with increasing seat height due to earlier offset of eccentric muscle contractions. Duration of BF eccentric contractions significantly increased with seat height due to a later eccentric contraction offset. Offset of GAST and BF muscle activation occurred earlier with increasing cadence. Cycling economy was significantly affected by cadence but not seat height. The results suggest that as a consequence of altered seat height, proprioceptive feedback is used to fine-tune the timing of bi-articular eccentric muscle contractions. These results may have implications for seat height self-selection.

Details

Original languageEnglish
Pages (from-to)223-229
JournalJournal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
Volume23
Issue number1
Early online date23 Sep 2012
Publication statusPublished - Feb 2013

Keywords

  • Cycling, Cadence, EMG, Seat Height, Concentric, Coordination