Biceps brachii: concentric and eccentric contraction.
Map of the root mean square value (RMS) of the longitudinal single differential signal on the surface of the biceps brachii muscle during concentric (weight up) and eccentric (weight down) contraction.
The short and long head of the biceps can be distinguished. The braking action (weight down, eccentric contraction) is not primarily provided by the biceps but by other flexors. Grid of 8x8 electrodes: Ø=3mm, inter-electrode distance =10mm. Maps are computed on 0.5s epochs and interpolated.