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.     

Optimizing segmental movement in the jumping header in soccer

This study looks at segmental movements in the jumping header from an optimization viewpoint. Investigations on the header so far have focused on head restriction in the movement but have not clarified how and to what extent body segments influence the performance of the skill. In the present study a biomechanical model was used to analyze the jumping header in simulated competition to give a clear picture of an optimized header. Skilled soccer players headed balls at speeds of 13 m x s(-1) the results indicated that the head moves as a free non-restricted segment in the jumping header and should be allowed to do so, even though much soccer literature says otherwise to prevent injuries. The arm movement showed individual characteristics and gave no general advantages in optimizing ball speed after impact in the header The movement of the legs was, on the other hand, the single most important factor in the skill. Therefore, coaches and players shouldfocus on developing muscle strength in the stomach, back and pelvis and should put no restrictions on head and arm movement to optimize the jumping header.     

The Penultimate Teaching Machine

This paper discusses the possibility of building an electronic transducer to take the place of the existing teaching machines. The tasks that can be performed by such a machine as well as the advantages and risks involved are discussed.     

The decline in CUNY applications: Who and how come

In the fall of 1976 applications for admission to the City University of New York (CUNY) had dropped sharply. In total number they were down by almost 13,000 from 1974, a drop of approximately 18%. Several hypotheses have been posited for the sharp decline in student applicants to the City University. Analysis of data drawn from the computer printouts of the City University's allocations indicates that the end of open admissions, for example, does not, in and of itself, explain the application drop. Similarly, the change in allocation formulas at CUNY seems not to explain the enrollment decline adequately. Finally, the imposition of tuition, or the perception about tuition, appears by no means the single most important factor in the enrollment drop. This paper attempts to determine the characteristics of the students not applying and to examine the reasons contributing to the sharp enrollment decline.