D13 Observational Technique

Topic

This assessment of the athlete's technique evaluates the overall quality of their movement pattern by comparing it to a reference model of optimal biomechanical technique—specifically, the same reference model used elsewhere in this suite to characterize the athlete's dynamic mode.

This technical assessment also incorporates the athlete's joint angles at key moments of the movement (matching the angles defined in another model in the suite), as well as their angular velocity, muscle activation timing (matching the timing defined in a different model in the suite), coordination between adjacent body segments, a final quality index for the dynamic mode, and bilateral asymmetry (matching the asymmetry defined in a model addressing biomechanical imbalance).

In swimming, a specific coordination index compares the swimmer's velocity to their stroke rate, thereby quantifying the technical efficiency of the stroke. In sprinting, a specific horizontal force index measures the orientation of the ground reaction force—specifically its forward-propulsive component—relative to the runner.

The similarity between the athlete's trajectory and the reference trajectory used to initiate this model is quantified either via a Pearson correlation coefficient or the same root-mean-square error used elsewhere in the suite to measure deviation in a dynamic mode. As the athlete's trajectory diverges further from the reference trajectory, the resulting root-mean-square error between the two trajectories increases. Consequently, this model—which begins with a reference model representing optimal technique—enables a continuous relative phase analysis to describe the athlete's actual final dynamic coordination between any pair of adjacent body segments over time. Drawing upon the comprehensive 3D kinematics established by another model in this suite, as well as the ground reaction force and muscle electrical signal defined by two other distinct models in the set, this diagnostic assessment determines the athlete's key joint angles, mode quality index, bilateral asymmetry, swimming coordination index, horizontal sprint force index, continuous relative phase, and the technical root-mean-square error that concludes this comprehensive model.

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