Model for assessment of the velocity and force at the start of sprint race.

A mathematical model was developed for the assessment of the starting velocity and initial velocity and force of a 100-m sprint, based on a non-homogeneous differential equation with the air resistance proportional to the velocity, and the initial conditions for [Formula: see text], [Formula: see text]The use of this model requires the measurement of reaction time and segmental velocities over the course of the race. The model was validated by comparison with the data obtained from 100-m sprints of men: Carl Lewis (1988), Maurice Green (2001) and Usain Bolt (2009), and women: Florence Griffith-Joyner, Evelyn Ashford and Drechsler Heike (1988) showing a high level of agreement. Combined with the previous work of the authors, the present model allows for the assessment of important physical abilities, such as the exertion of a high starting force, development of high starting velocity and, later on, maximisation of the peak running velocity.

Model for the determination of instantaneous values of the velocity, instantaneous, and average acceleration for 100-m sprinters.

Temporal patterns of running velocity is of profound interest for coaches and researchers involved in sprint racing. In this study, we applied a nonhomogeneous differential equation for the motion with resistance force proportional to the velocity for the determination of the instantaneous velocity and instantaneous and average acceleration in the sprinter discipline at 100 m. Results obtained for the instantaneous velocity in this study using the presented model indicate good agreement with values measured directly, which is a good verification of the proposed procedure.

Isometric force development of some muscle groups in athletes.

In a large sample of both male and female athletes, subdivided by age and sex, a development curve of isometric muscule force (F) was analyzed for hand flexors, upper-body flexors and extensors, and knee extensors (PDS). A sample of 1,857 male and 1,009 female athletes, aged 8-30 years, subdivided by their age and sex, was used to measure the mean values of isometric muscle force of certain muscle groups by way of 5 topologically defined tests. Based on the results, isometric muscle force (F) development curves are shown and analyzed for the right-hand and left-hand (PLS) flexors, upper-body flexors (PTR), upper-body extensors (OTR), and knee extensors (ONO).