**1.2 Spasticity**

Among these changes, which gradually develop, spasticity represents the principal sign detectable. A simple definition of spasticity is an *increase in velocitydependent stretch reflexes* [9, 10] which can be evoked at rest by muscle stretch or tendon taps.

Principal key points:


### **1.3 Spastic dystonia**

The term "spastic dystonia" was coined by Denny-Brown in 1966 to define tonic-chronic muscle activity that is present in a spasticity pattern, during rest [15]. Thus, spastic dystonia could be described as a spontaneous overactivity at rest, not induced by a primary triggering factor [14–16]. It is easy to recognise it in patients with spastic paresis, as spastic dystonia causes specific bad postures in joints and body. For example, in the upper limb, the shoulder can stay internally rotated and adducted with a flexed and pronated elbow and flexed wrist and fingers. Equinovarus deformity represents a specific spastic dystonia in the lower limb, and it is characterised by plantar flexors and/or toe flexors, which may be painful and disabling during walking.

### **1.4 Spastic co-contraction**

Spastic co-contraction is defined as an "unwanted, excessive, level of antagonistic muscle activity during voluntary command on an agonist muscle, which is aggravated by tonic stretch in the co-contracting muscle" [13]. Spastic co-contraction in spasticity pattern is a descending phenomenon, most probably due to misdirection of the supraspinal drive. It may be caused by loss of reciprocal inhibition during voluntary command [9, 10]. So, voluntary command of an agonist muscle is the first step, which induces spastic co-contraction. In patients with good or fairly good motor control, spastic co-contraction is certainly the most disabling form of muscle overactivity, because it obstacles muscle physiological muscle voluntary recruitment.

### **1.5 Clinical evaluation**

### *1.5.1 Passive range of motion*

For each movement evaluated, the corresponding muscles and joints are stretched at a very slow speed, in order to keep below the threshold for eliciting a stretch reflex. The angle at which soft tissue offers a maximum resistance is defined as the passive range of motion for that joint [17].

### *1.5.2 Angle of catch or clonus and spasticity grade*

For each movement evaluated, the clinician should stretch the corresponding muscles and joints as fast as possible for the examiner. The spasticity grade is determined by the joint angle at which catch or clonus appears, according to Tardieu scale [18].

### *1.5.3 Active range of motion*

For each passive movement evaluated at first, the clinician asks the patient to carry out an active movement at maximal range, until the active movement produced by the agonist muscles is contrasted by the passive resistance together with the spastic co-contraction of antagonist ones. This angle measure is the effective active range of motion [18].

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*Spasticity and Dystonia: A Brief Review DOI: http://dx.doi.org/10.5772/intechopen.91780*

1.Quality of muscle reaction.

2.Angle of muscle reaction.

sit and supine position. There are two types of measures:

The quality of muscle reaction is scored as follows (range 0–4):

0.No resistance throughout the course of the passive movement.

Tardieu score is a scale realised to measure spasticity that evaluates resistance to passive movement at both slow and fast speed. Individuals are evaluated both in in

1.Slight resistance throughout the course of the passive movement, followed by

2.Clear catch at precise angle, interrupting the passive movement, followed by

3.Fatigable clonus (<10 seconds when maintaining pressure) occurring at precise

4.Infatigable clonus (>10 seconds when maintaining pressure) occurring at

The angle of full ROM (R2) is defined at a very slow speed (V1). The angle of muscle reaction (R1) is detected when a catch or clonus appears during a quick

Ashworth scale, original version (1964), is a test which quantifies resistance to passive movement, with respect to a joint and with varying degrees of velocity.

1.Slight increase in tone giving a catch when the limb was moved in flexion or

In order to consider joint angle, speed movement has to be defined:

*1.5.4 Outcome measure*

release.

release.

angle.

precise angle.

• V1 is slow as possible.

• R2 as the full PROM.

stretch (V3) [19].

Scores range from 0 to 4:

extension.

0.No increase in tone.

• V2 speed of limb falling under gravity.

Regarding the joint angle, modified Tardieu describes:

2.More marked increase in tone but limb easily flexed.

• V3 moving as fast as possible.

• R1 as the angle of muscle reaction.
