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Although soccer is a popular sport worldwide, little work has been done to satisfy the increasing demand for quantitative research on female players. As a result, training programmes for female players are often taken directly from their male counterparts, without appropriate adaptations. In this study, I examine the influence of gender and experience on the maximal instep soccer kick among male and female college students, with equal numbers of novice and skilled players. The data collection equipment consisted of a synchronized system with VICON TM 3D motion capture (nine high-speed cameras, 120 Hz) and NORAXON wireless electromyography. Results showed that trained male and female players have different techniques. After a powerful kick, males naturally follow through with a jump to dissipate residual leg momentum, whereas females avoid this airborne phase; instead, they counteract the momentum with upper-body flexions. Skilled male players displayed a more powerful quasi whip-like movement of the kicking leg and more explosive muscle work patterns (higher maximum and faster increase rate of muscle tension) than skilled females. During training, practitioners should pay special attention to repetitive injuries in small muscles like the adductor magnus. The differences observed may be important for the development of training programmes.

No existing studies of badminton technique have used full-body biomechanical modeling based on three-dimensional (3D) motion capture to quantify the kinematics of the sport. The purposes of the current study were to: 1) quantitatively describe kinematic characteristics of the forehand smash using a 15-segment, full-body biomechanical model, 2) examine and compare kinematic differences between novice and skilled players with a focus on trunk rotation (the X-factor), and 3) through this comparison, identify principal parameters that contributed to the quality of the skill. Together, these findings have the potential to assist coaches and players in the teaching and learning of the forehand smash. Twenty-four participants were divided into two groups (novice, n = 10 and skilled, n = 14). A 10-camera VICON MX40 motion capture system (200 frames/s) was used to quantify full-body kinematics, racket movement and the flight of the shuttlecock. Results confirmed that skilled players utilized more trunk rotation than novices. In two ways, trunk rotation (the X-factor) was shown to be vital for maximizing the release speed of the shuttlecock – an important measure of the quality of the forehand smash. First, more trunk rotation invoked greater lengthening in the pectoralis major (PM) during the preparation phase of the stroke which helped generate an explosive muscle contraction. Second, larger range of motion (ROM) induced by trunk rotation facilitated a whip-like (proximal to distal) control sequence among the body segments responsible for increasing racket speed. These results suggest that training intended to increase the efficacy of this skill needs to focus on how the X-factor is incorporated into the kinematic chain of the arm and the racket.

Many studies try to understand fundamental soccer skills, most focusing on kicking. However, a full picture of an efficient kick remains incomplete owing to constraints of test designs and difficulties that arise in synchronizing and analyzing information generated by multiple assessment techniques. Previous scientific studies may be generally categorized as: two-dimensional kinematic analysis using high-speed cameras, muscle activity studies using electromyography, three-dimensional analysis of the kicking-leg using a partial-body model, and kinetic studies using force measurements and modelling. No existing inquiries have used full-body three-dimensional motion capture and modelling to examine kicking. The current study remedies this deficiency and defines a full-body model capable of revealing more detailed characteristics of kicking. Additionally, it reveals effects of long-term training by comparing novices with skilled athletes and explores new parameters that have potential to aid quantitative evaluations of skill. Results show effective upper-body movement to be a key factor in creating better initial conditions for a more explosive muscle contraction during kicking. It permits a more powerful quasi whip-like movement of the kicking leg. Finally, the timely change of distance between the kick-side hip and the non-kick-side shoulder provides a quantitative means of measuring kick quality.