SESSION IX Title: STRETCHING AND EXERCISE: BENEFITS AND DOWNSIDES FOR SKELETAL MUSCLE. A MULTI-ELECTRODE ARRAY APPROACH TO MUSCLE FIBERS CONDUCTION VELOCITY ESTIMATION DURING DYNAMIC EXERCISES GizziI

The possibility of investigating motor control strategy from myoelectric signal has been variously addressed using needle or surface EMG (sEMG) with controversial results. Nevertheless, sEMG time-domain or frequency domain parameters provided some reliable informations about the phisical phenomena underlying sEMG signal generation. In general, it has been accepted that: • Amplitude content of sEMG reflects the level of muscle activation; • Spectral content of the myolectric signal provides indirect information related to the quality of active MU. However, sEMG spectral parameters are strongly influenced by a number of factors thus their reliability is largely questioned. On the other hand, muscle fibre conduction velocity (CV) is an important physiological parameter because it allows the non invasive assessment of motor units recruitment-derecruitment (1) and thus the modification of the peripheral properties of the neuromuscular system as a consequence of exercise. Estimation of CV from sEMG recording is a complex task and asks for a complex experimental set-up which uses multi-electrode array configurations. In this paper, we present CV estimation methods used in our laboratory and a set of the different results we obtained.