Downhill Slide

2 Pages 486 Words

The article explains that freestyle is the fastest form of locomotion for fluid movement.
The article also discusses statistical testing to understand front stoke in swimming and it mechanical link to the fluid forces required in non-propulsive directions. This examined underlying mechanics of the observed relationships among stoke frequency, stroke length, body roll, and speed.
Experimental data was collected from professional swimmers on strategies used to change stroke frequency to swim faster. Stroke frequency is determined by the swimmers desired efforts (Yanai). Three factors are suggested to determine stroke frequency: (a) inertia of the arm about the shoulder, (b) range of motion through which the arm moves, (c) torque applied to the arm though out the shoulder (Yanai). These factors alone do not increases stoke frequency (Yanai). Increase in trunk roll cycle and body roll also will increase stroke frequency (Yanai).
It is explained that the trunk roll uses external forces that act in non propulsive directions. This is a constraint to a swimmers propulsion and efficiency (Yanai 2001). These factors have an effect on the swimmers stroke frequency, stroke length, and speed (Yanai). With this in mind Yanai made two predictions (1) body roll and effect of non-propulsive forces on the body will predict stroke frequency. (2) Swimmers will reduce fluid forces in non-propulsive directions in the body roll cycle by increasing stroke frequency.
The hypothesis’s above were tested using Euler’s equation of motion, experimental videography technique with panning periscopes, DLT-based algorithm, 3X 3 matrix, and correlation analysis. These research methods studied the body roll, moment of inertia of the body about the axis, turning effect of fluid forces and global maximum.

These hypotheses were supported by the formulas outcomes. The formulas found true to the fact that stoke frequency was predicted well with the...