A comparison of methods to determine bilateral asymmetries in vertical leg stiffness. Issue 9 (2nd May 2016)

• Record Type: Journal Article
• Authors: Maloney, Sean J.; Fletcher, Iain M.; Richards, Joanna
• Is Part Of: Journal of sports sciences. Volume 34:Issue 9(2016)
• Page Start: 829
• Page End: 835
• Publication Date: 2016-05-02
• Subjects: Leg-spring behaviour -- centre of mass displacement -- spring-mass model; Sports -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Psychological aspects -- Periodicals; 612.044
• DOI: 10.1080/02640414.2015.1075055
• Languages: English
• ISSNs: 0264-0414

Abstract

ABSTRACT: Whilst the measurement and quantification of vertical leg stiffness ( K vert ) asymmetry is of important practical relevance to athletic performance, literature investigating bilateral asymmetry in K vert is limited. Moreover, how the type of task used to assess K vert may affect the expression of asymmetry has not been properly determined. Twelve healthy males performed three types of performance tasks on a dual force plate system to determine K vert asymmetries; the tasks were (a) bilateral hopping, (b) bilateral drop jumping and (c) unilateral drop jumping. Across all the three methods, K vert was significantly different between compliant and stiff limbs ( P < 0.001) with a significant interaction effect between limb and method ( P = 0.005). Differences in K vert between compliant and stiff limbs were −5.3% ( P < 0.001), −21.8% ( P = 0.007) and −15.1% ( P < 0.001) for the bilateral hopping, bilateral drop jumping and unilateral drop jumping methods, respectively. All the three methods were able to detect significant differences between compliant and stiff limbs, and could be used as a diagnostic tool to assess K vert asymmetry. Drop jumping tasks detected larger K vert asymmetries than hopping, suggesting that asymmetries may be expressed to a greater extent in acyclic, maximal performance tasks.