Time-frequency analysis of surface myoelectric signals during athletic movement

Considers muscle activation and fatigue during propulsion of a racing wheelchair. The authors discuss a single case study on the modality of muscle activation during the propulsion of a racing wheelchair. To investigate muscle coordination, muscle fatigue, and the strategies that the subject exploits to counteract the effects of muscle fatigue and keep a high level of performance, the authors first studied the activation intervals of seven trunk and upper limb muscles and then studied the evolution in time of their spectral content by means of two different approaches, according to the statistical properties of their myoelectric signals. Angle, angular velocity, and angular acceleration of the elbow joint have also been considered. This combined approach allowed the authors to obtain different results important to gaining a deeper insight in the differences among the observed muscles in this specific exercise.