Biokinematic analysis of human performance: sprint starts in speed skating

Three dimensional analysis of the human body during the performance of a physical activity is becoming more and more common. Three dimensional computer graphics displays of reconstructed data in the form of human body models support this quantitative analysis. Sprint starts in 500m and 1000m speed skating events are as important to winning as they are in short distance running events. Fractions of a second lost as a skate slides backwards during the application of an impulsive force could cost a skater a win. Recognition of the relative motion components of this task could lead to improved performance. This paper will discuss the acquisition and analysis of 3-D human motion data during the performance of sprint starts in speed skating. The components of this system include 2 high-speed cinematographic cameras, a rear projection digitizer, algorithms for DLT, smoothing, linear and angular quantitative analysis, a 13 segment human body model, and an IBM workstation capable of high resolution, three-dimensional graphics. There are three strengths to this system, they are: 1) its ease of use in a sports arena environment, 2) its relative accuracy, and 3) its three-dimensional computer graphics display of results.