Classification of muscle spindle afferents in the peroneus brevis muscle of the cat.

Muscle-spindle afferents are commonly classified according to their conduction velocity. Under certain conditions such classifications may not be feasible and another form of identification is required. In this study 5 tests, comprising either quantitative or qualitative criteria, have been evaluated as a means of classifying spindle afferents. The choice of these tests was made on the basis of predicted physiological differences arising from the structural variations in the endings. Prior conditioning of the spindles was found to enhance the distinction between the two types of afferent. All the tests generated similar identifications with a maximum of 10% of afferents being classified differently by any two tests.