Optimality in the encoding/decoding relations of motoneurones and muscle units

Experimental data indicate the existence of a matching between many motoneurone characteristics and those of the corresponding innervated muscle fibres. This association between the properties of motoneurones and muscle fibres is quite important for the adequate and efficient functioning of the motor system. We present a view of motoneurones and muscle fibres as encoders and decoders of signals. An analysis of some of the encoding/decoding relations performed by motoneurones and muscle fibres in functionally relevant situations indicates that they are optimal and we indicate in the paper what performance measures are optimised. Besides its relevance in the study of motor control, the encoding/decoding framework should also be useful in the task of model validation.