The main purposes of the current study were to examine bilateral asymmetry in postural control during single-leg standing between the dominant and non-dominant legs using a novel analysis approach based on principal component analysis (PCA). It was hypothesized that the asymmetry might manifest as differences in the coordinative structure (control strategies), or as differences in the frequency or regularity of corrective interventions of the motor control system. The static and dynamic leg dominance of 26 active young adults (14 males and 12 females) was determined from their preferred leg for dynamic and for static tasks. Then postural movements during one-leg standing were recorded with a standard marker-based motion capture system and analyzed by a PCA. The coordinative structure of postural movements was quantified using the relative variance of the principal movement components (PMs). Then the PMs were differentiated to obtain postural accelerations, from which two variables characterizing the activity (frequency and regularity) of the postural control system were derived. There were no differences in the coordinative structure, neither for dynamic nor for static leg preference. However, both variables characterizing asymmetries in the postural accelerations showed significant differences in specific PMs. Dynamic leg dominance yielded more and larger effects than static leg dominance. In the opinion of the authors, the PM-specificity of limb dominance agrees with principles of movement control derived from optimal feedback control theory. In summary, the current study suggests that leg dominance should be considered in clinical testing; different effects in different movement components should be expected; and one-leg standing should be seen as a dynamic, rather than as a static task.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.humov.2018.02.003 | DOI Listing |
Sports Biomech
January 2025
School of Athletic Performance, Shanghai University of Sport, Shanghai, China.
The aim of this study was to investigate the relationships between knee and ankle strength and horizontal deceleration performance following different sprint distances. Fifty-seven ( = 41male, = 16 female) youth team-sports athletes completed: a) 5-m and 10-m horizontal deceleration ability (HDA) tests; b) concentric (60°/s, 180°/s) and eccentric (30°/s) relative peak torque (PT) measurements of the knee extensor (KE) and flexor (KF) muscles and the ankle plantarflexion (APF) and dorsiflexion (ADF) muscles in an isokinetic dynamometer. Pearson's correlation coefficients revealed that concentric at 60°/s and eccentric at 30°/s KE were mostly related to deceleration performance both in HDA ( = -0.
View Article and Find Full Text PDFEur J Sport Sci
February 2025
Department of Sport and Health Sciences and Social Work, Oxford Brookes University, Oxford, UK.
Some technical limitations to using the eccentric mode to measure peak eccentric strength of the hamstrings (PTH) were raised. PTH also has limited validity to predict performance or injury risk factor. Therefore, our aim was to compare PTH and other isokinetic variables tested in the eccentric and passive modes.
View Article and Find Full Text PDFUltrasound Med Biol
January 2025
School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan ROC; Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan ROC. Electronic address:
Objective: This study aimed to validate the ultrasound speckle tracking (UST) algorithm, determine the optimal probe location by comparing normalized cross-correlation (NCC) values of muscle displacement at two locations (proximal vs. middle) of the biceps femoris long head (BFlh) using the UST, and investigate the effects of Nordic hamstring curl exercise (NHE) training on BFlh displacement.
Methods: UST efficacy was verified with ex vivo uniaxial testing of porcine leg muscles.
Sensors (Basel)
January 2025
College of P.E. and Sports, Beijing Normal University, Beijing 100875, China.
Objective: This study aimed to investigate the effects of a 12-week self-designed exercise game intervention on the kinematic and kinetic data of the supporting leg in preschool children during the single-leg jump.
Methods: Thirty 5- to 6-year-old preschool children were randomly divided into an experimental group (EG) and a control group (CG). The BTS SMART DX motion capture analysis system was used to collect single-leg jump data before the intervention.
Bioengineering (Basel)
January 2025
School of Engineering, Grand Valley State University, Grand Rapids, MI 49504, USA.
In quiet standing, the central nervous system implements a pre-programmed ankle strategy of postural control to maintain upright balance and stability. This strategy comprises a synchronized common neural drive delivered to synergistically grouped muscles. This study evaluated connectivity between EMG signals of the unilateral and bilateral homologous muscle pairs of the lower legs during various standing balance conditions using magnitude-squared coherence (MSC).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!