Gender differences among sagittal plane knee kinematic and ground reaction force characteristics during a rapid sprint and cut maneuver

Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz). Differences (p < . 05) were observed between groups for knee flexion at contact and GRF at maximum knee flexion. Women averaged 5.8 degrees less flexion at contact and 1.0 N. (kg x m x s(-1))(-1) greater GRF at maximum flexion. Knee range of motion and peak GRF variables were not significantly different, but women had greater values. Women exhibited technique characteristics believed to increase ACL injury risk, but men exhibiting similar characteristics were also observed and could also be at risk.     

Maximal-intensity isometric and dynamic exercise performance after eccentric muscle actions

A well-documented observation after eccentric exercise is a reduction in maximal voluntary force. However, little is known about the ability to maintain maximal isometric force or generate and maintain dynamic peak power. These aspects of muscle function were studied in seven participants (5 males, 2 females). Knee extensor isometric strength and rate of fatigue were assessed by a sustained 60 s maximal voluntary contraction at 80 degrees and 40 degrees knee flexion, corresponding to an optimal and a shortened muscle length, respectively. Dynamic peak power and rate of fatigue were assessed during a 30 s Wingate cycle test. Plasma creatine kinase was measured from a fingertip blood sample. These variables were measured before, 1 h after and 1, 2, 3 and 7 days after 100 repetitions of the eccentric phase of the barbell squat exercise (10 sets x 10 reps at 80% concentric one-repetition maximum). Eccentric exercise resulted in elevations in creatine kinase activity above baseline (274+/-109 U x l(-1); mean +/- s(x)) after 1 h (506+/-116 U x l(-1), P < 0.05) and 1 day (808+/-117 U x l(-1), P < 0.05). Isometric strength was reduced (P < 0.05) for 7 days (35% at 1 h, 5% at day 7) and the rate of fatigue was lower (P < 0.05) for 3 days at 80 degrees and for 1 day at 40 degrees. Wingate peak power was reduced to a lesser extent (P < 0.05) than isometric strength at 1 h (13%) and, although the time course of recovery was equal, the two variables differed in their pattern of recovery. Eccentrically exercised muscle was characterized by an inability to generate high force and power, but an improved ability to maintain force and power. Such functional outcomes are consistent with the proposition that type II fibres are selectively recruited or damaged during eccentric exercise.     

A review of batting in men's cricket

In this review, we critically evaluate the scientific research into the morphology and physiology of cricket batsmen. We consider all aspects of the motor control of this skill, in the context of research into dynamic interceptive actions, the biomechanics (kinematics and kinetics) of the various phases of batting strokes and injuries to batsmen. Some attention is also devoted to batting equipment and to psychological factors in batting. Because of the lack of published scientific research into women's cricket, this review focuses on the men's game and covers research on batsmen of various playing standards. For the future, we see as a high priority research into injury mechanisms, rather than simple injury statistics, and the role of cricket equipment design in injury prevention. A second priority is for multi- or inter-disciplinary research, linking the biomechanics of batting to the underlying motor control of the movements and the effect of environmental information. Biomechanical studies of the variability of the batsman's movements are needed, and these should be related to the compensatory variability proposal of ecological psychology. Clearly, there is also a need for scientific research into batting in women's cricket, which has been inadequately researched to date.