Does minimizing co-contraction increase agility test performance?

Article type: Research Article

Authors: Arpinar-Avsar, Pinar^* | Celik, Huseyin

Affiliations: Department of Biomechanics and Motor Control, Hacettepe University, Faculty of Sport Sciences, Ankara, Turkey

Correspondence: [*] Corresponding author: Pinar Arpinar-Avsar, Department of Biomechanics and Motor Control, Hacettepe University, Faculty of Sport Sciences, Ankara, Turkey. Tel.: +90 535 293 00 95; Fax: +90 312 299 21 67; E-mail: [email protected].

Abstract: BACKGROUND: The majority of common agility tests include pre-planned change of direction (COD) maneuvers which require muscular coordination. However, muscular coordination in terms of organization of co-activated antagonistic muscle pairs in COD maneuvers have not been studied. OBJECTIVE: To evaluate muscle coordination by analyzing co-contraction at knee and ankle during three agility tests and to investigate the relationships between muscle coordination and test completion time. METHOD: Thirteen healthy young male subjects (22.1 ± 1.9 years) participated in the study. Surface EMG and acceleration signals were used to calculate co-contraction index (CCI) for selected antagonistic muscle pairs of ankle and knee joints during COD maneuvers in agility tests. RESULTS: The findings indicated that concurrent activation costs a delay to complete the test faster. CCI was higher at right ankle and left knee and showed an increasing trend with advancing the phase when the test requires multiple CODs. CONCLUSIONS: Minimizing co-contraction would result in faster movement, however, there might be a trade-off between joint stiffness and test performance depending on changes in neuromuscular factors such as altered motor control strategies due to strength imbalances or occurrence of fatigue.

Keywords: Agility, muscle coordination, co-contraction, acceleration

DOI: 10.3233/IES-192217

Journal: Isokinetics and Exercise Science, vol. 28, no. 2, pp. 111-118, 2020