The relative velocity (for a repeated measure) during administration of the Tardieu Scale assessment to measure muscle reaction through evaluation of spasticity and resistance to passive limb movement in a participant/subject.

V1 – As slow as possible, slower than the natural drop of the limb segment under gravity;V2 – Speed of limb segment falling under gravity;V3 – As fast as possible, faster than the rate of the natural drop of the limb segment under gravity;

Measurements take place at 3 velocities (V1, V2, and V3). Responses are recorded at each velocity as X/Y, with X indicating the 0 to 5 rating, and Y indicating the degree of angle at which the muscle reaction occurs.

1;2;3;

Key Reference:
Tardieu G, Shentoub S, Delarue R. (1954) Research on a technic for measurement of spasticity. Rev Neurol (Paris), 91(2): 143–144.
Other References:
Ansari, N. N., Naghdi, S., Hasson, S., Azarsa, M. H., & Azarnia, S. (2008). The Modified Tardieu Scale for the measurement of elbow flexor spasticity in adult patients with hemiplegia. Brain Inj, 22(13-14), 1007–1012.
Boyd, R., & Graham, H. K. (1999). Objective measurement of clinical findings in the use of botulinum toxin type A for the management of children with CP. Eur J Neurol, 6(Suppol 4), S23–S35.
Gracies, J. M., Burke, K., Clegg, N. J., Browne, R., Rushing, C., Fehlings, D., . . . Delgado, M. R. (2010). Reliability of the Tardieu Scale for assessing spasticity in children with cerebral palsy. Arch Phys Med Rehabil, 91(3), 421–428.
Haugh AB, Pandyan AD, Johnson GR. (2006). A systematic review of the Tardieu Scale for the measurement of spasticity. Disabil Rehabil, 28(15): 899–907.
Morris, S. (2002). Ashworth And Tardieu Scales: Their Clinical Relevance For Measuring Spasticity In Adult And Paediatric Neurological Populations. Phys Ther Rev, 7(1), 53–62.