Tone + coordination

Definition + contributing factors to tone

Definition	Contributing factors
resistance of normal relaxed limb to passive stretch *There is a normal level of tone for a certain task ( tonicity dependent on the task )	Physical inertia of limb  Passive mechanical elastic properties of tissues

Hypertonus definition + causes

Definition	Causes
Increased resistance to passive stretch in relaxed muscle	Contracture:  Increased stiffness due to changes in the mechanical properties of the soft tissue  Spasticity:  Abnormal reflex muscle contraction → velocity dependent increase in tonic stretch reflex

Why does hypertonus happen in upper motor neuron pathology

→ hypertonus 

→ heightened stretch reflex → X relaxation before triggering 

→ reduction of control of inhibitory pathways for reflexes 

→ reinstate descending control 

→ series of Mx for hypertonicity

Spasticity definition + impact

Definition	Impact
Velocity dependent increase in tonic stretch reflex  → exaggerated tendon jerks  → causes: hyper-excitability of neurons involved in stretch reflex bc upper motor neuron syndrome  Intensity dependent on:  Speed of movement  Length of muscle at which it is stretched  Overall length of muscle	X impact activity  X impact recovery  May lead to contractures

Definition + impact of contractures

Definition	Impact
Increase in resistance to passive stretch  → cause: changes in passive mechanical properties of muscle  Muscle changes from immobilisation:  Atrophy Loss of sarcomeres  Accumulation of connective tissue  Increased fat content  Degenerative changes at musculotendinous junction  Weakness of muscle leads to development of contractures	Contractures not main contributors to activity limitations in subacute phase

Why manage spasticity + contracture

1. Significant impact on function + activity if not prevented 

2. Pain 

3. Hygiene 

4. Cosmesis 

5. More significant impact on patients of other pathologies

Tardieu measurement of tone

Lower limb : Supine lying down 

Upper limb: sitting 

Test conditions: 

Velocity 1( V1): less than pull of gravity 

Velocity 2: pull of gravity 

Velocity 3: faster than pull of gravity

Outcome measures: 

X: quality of muscle reaction [ score from 0-5]

0: X resistance throughout passive movement 

1: slight resistance throughout 

2: Clear catch at precise angle then release 

3: fatiguable clonus at precise angle 

4: unfatigueable clonus at precise angle 

5: immobile joint

Y: angle in degrees where the muscle reaction occurs 

Cerebellar disorders + areas affected + symptoms

	Area affected	Symptoms
Midline ( vermis )	Imbalance- truncal	Lower tone  Nystagmus Ocular dysmetria Poor pursuit
Hemispheric cerebellar syndromes	Incoordination of limb  → dysmetria → disdiadokokinesia	Dysarthric  Intention tremor

Locations of lesions + function of area + impacts on coordination ( cerebellar hemisphere )

Location of lesions	Function	Impacts
Intermediate zones	Regulation of  Timing  Amplitude  Trajectory of elevation + descent	Ataxia in ipsilateral limbs

Locations of lesions + function of area + impacts on coordination ( vermis )

Location of lesions	Function	Damage alignments
Medial cerebellar region	Alternative locomotor pattern from sensory feedback from limbs  → lesion causes loss of spinal + vestibular input → affects balance	Gait  Sitting balance  Eye movements + speech usually spared

Locations of lesions + function of area + impacts on coordination ( flocculonodular lobe )

Function	Damage alignments
Control of balance + locomotion  Control extensor tone  Modulation control over rhythmic flexor/ extensor activation tone  Vestibular integration  Ocular integration	Integration of vestibular + ocular affected  → spatial/ timing/ position sense

Function of inferior cerebellar peduncles

Receive sensory info from body + transmits to cerebellum 

→ proprioception to motor 

→ afferent: medulla 

→ efferent: vestibular nuclei

Functions of middle cerebellar peduncles

Receive desired movement for position of limbs 

Afferent: basilar pons

Functions of superior cerebellar peduncles

Takes integrated info from cerebellum → midbrain  Efferent: cerebellar nuclei → pons/ medulla/ spinal cord/ cerebrum

Explanation for dysmetria + observation in Ax + test

Explanation	Observation in Ax	Test
Inaccurate amplitude of movement + misplaced force  → overshooting/ undershooting  → veer from path of movement Serial dysmetria → multiple joint movement + degradation of multi-joint coordination  Characteristics of movement:  Wobbly/ erratic  Sluggish force development/ cessation  Impairment of scaling of force amplitude  Veering from path of movement	Accuracy  → small targets → greater precision	Finger nose finger test Heel-shin/ knee test

Explanation for dyssynergia + observation in Ax

Explanation	Observation in Ax
Decomposition of movement  → cause: lack of coordination bwt agonist + antagonist + synergic muscles  Characteristics of movement:  → variable + suboptimal muscle activation of muscles  → accelerations of different joints X scaled in proper proportion to each other  → veering from the path of movement	Amplitude  → larger movements → more time for submovement errors

Explanation for dysdiadochokinesia + observation in Ax

Explanation	Observation in Ax
Difficulty w/ rapid alternating movements  → rhythm/ timing issues	Speed → fast distal movements → greater proximal control for optimal distal movements

Tests for dysdiadochokinesia

• Alternating movements 

• Movement requiring rhythm 

• Rebound testing

Other clinical functional signs indicating issues w/ coordination

1. Restriction of amplitude of movement 

2. Restriction of degrees of freedom 

3. Excessive pre-shaping + use of support surface during upper limb tasks 

4. Excessive BOS, stepping, use of arms during standing + walking 

5. Increased speed + difficulty slowing down in walking 

6. Increased variability of performance

Tests for coordination

Tests of aggravating movements/ timed tests

Ax of functional coordination

Tests of aggravating movements/ timed tests components

Ax components

→ Multi-joint movements  → Agonist, antagonist, synergist muscle activity  Foot taping  Heel-knee-shin  Finger-to-nose  Rapid pronation-supination  Hand tapping  Finger strumming/ tapping  Rapid opposition  → Increasing speed to provoke symptoms

Observations in tests of aggravating movements

1. Speed 

→ speed up/ slow down purposefully 

2. Timing: synchronous + timed segments 

3. Smoothness

4. Ability to follow sequence of actions 

5. Accuracy ( timing/ speed/ force )

Ax components for functional coordination

Ax components

Heel-toe walking forwards + backwards  Progression:  Speed Direction changes  Stopping + starting movement Braiding: walk forwards/ sideways  crossing one leg over other Running/ skipping/ hopping  Star jumps : legs only → add hands  Skipping w/ rope  Cross over jumps  Ball skills  Progression:  Hands ( one/ alternate  Size of balls  Added/ w/o bounce