Spasticity, rigidity, hypotonia, dystonia, decerebrate rigidity, and decorticate rigidity are abnormal tones that can occur. Examination of tone includes initial observation, passive and active motion testing using scales like the Modified Ashworth Scale. Typical patterns of spasticity in upper and lower limbs are described for upper motor neuron lesions.

1. S U VA R N A G A N V I R
P R O F E S S O R
D V V P F ’ S C O L L G E O F P H Y S I O T H E R A P Y, A H M E D N A G A R
TONE

2. OBJECTIVES
• Introduction
• Abnormal Tone- Spasticity
Rigidity
Hypotonia
Dystonia
Decerebrate Rigidity
Decorticate Rigidity
• Examination of tone
• Modified Ashworth Scale
• Typical patterns in UMN lesion

3. INTRODUCTION
• Definition: Resistance of muscle to passive elongation or stretch when an
individual attempts to maintain muscle relaxation.
• Factors 1. Physical Inertia
2. Intrinsic mechanical elastic stiffness
3. Reflex muscle contraction ( tonic stretch reflex)
• TONAL ABNORMALITIES -
Hypotonia
 Hypertonia-Spasticity and Rigidity
 Dystonia
 Decerebrate and Decorticate Rigidity

4. ABNORMAL TONE
SPASTICITY
• Hypertonic motor disorder
• Velocity dependent
• Clasp- knife response
• Chronic spasticity- abnormal posture, deformity, disability
• Injury to pyramidal tract- UMN lesion
• Loss of inhibitory control over lower motor neurons
• Results in disordered spinal segmental reflexes
• Increased alpha motorneurone excitability

5. • Sign and symptoms-
 hyperactive stretch reflexes
 Involuntary flexor and extensor spasms
 Babinski’s sign positive –Abnormal plantar reflex
 Exaggerated deep tendon reflexes
 Loss of precise autonomic control
 Clonus- cyclic, spasmodic alteration of muscle
contraction relaxation in response to muscle stretch of
a spastic muscle. Common in plantar flexors…

7. RIGIDITY
• Hypertonic state
• Increased uniform resistance that persists throughout the whole ROM
(leadpipe)
• Cause- lesion of the basal ganglia system ( Parkinson’s disease)
• Stiffness, inflexibility, Significant functional limitation.
• Due to excessive supraspinal drive (UMN facilitation)
• Spinal reflex mechanisms are normal.
• Cogwheel- Hypertonic state with superimposed rachetlike jerkiness,
commonly in UE movement e.g Elbow flexion/ extension)

8. HYPOTONIA
• Flaccidity- Absent muscular tone
• Resistance to passive movement is diminished
• Stretch reflexes are dampened or absent, limbs are floppy
• Occurs in Lower Motor Neuron Lesion- affection of ant horn cell and
peripheral nerves
• Symptoms- Decreased or absent reflexes, paresis or paralysis, muscle
fasciculation and fibrillation, muscle atrophy.
• Temporary states of flaccidity or hypotonia- Spinal Shock/ cerebral
Shock depending upon location of lesion.

9. DYSTONIA
• Hyperkinetic movement disorder characterized by disordered tone and
involuntary movements involving large portion of the body.
• Movements are similar to athetoid movements with typical
twisting/writhing motions.
• Dystonic Posturing- sustained abnormal postures due to co-contraction of
muscles.
• Result from a CNS lesion (Basal Ganglia).
• Focal Dystonia- Affects only one part of the body e.g spasmodic torticollis.
• Segmental Dystonia- Affects two or more adjacent areas e.g dystonic
posturing of arms.

10. DECEREBRATE RIGIDITY
• Abnormal Extensor Response - refers to sustained
contraction and posturing of the trunk and lower limbs in a
position of full extension.
• Indicative of corticospinal brainstem lesion between superior
colliculus and vestibular nucleus.
• Elbows- extended, Shoulders- adducted, Forearm- pronated,
wrist and fingers- flexed, lower limb- stiff extension and
plantarflexion.

11. DECORTICATE RIGIDITY
• Abnormal Flexor Response -refers to sustained
contraction and posturing of upper limbs in flexion and
lower limbs in extension.
• Is indicative of corticospinal tract lesion at the level of
diencephalon
• Elbows, wrist and fingers- flexion, Shoulder- adducted,
lower limb- Extension, I.R and plantarflexed.

12. EXAMINATION OF TONE
• Consists of
 Initial Observation of resting posture and palpation
 Passive motion testing
 Active motion testing

13. • Tone is variable in nature. Hence depends on
following factors
 Volitional effort and movement
 Stress and anxiety
 Position and interaction of tonic reflexes
 Medications
 General health
 Environmental temperature
 State of CNS arousal and alertness
 Urinary bladder status
 Fever and infection
 Metabolic and or electrolyte imbalance

14. • Initial Observation and palpation
 Abnormal posturing of limbs or body.
 With spasticity- fixed posturing in synergy pattern
 Flaccidity – limbs appear floppy and lifeless
 With palpation –
 gives more information about resting state of a muscle
 Consistency , firmness and tergor should be examined
 Hypertonic muscle – feels taut and harder
 Hypotonic muscle – feels soft and flabby

15. TYPICAL PATTERNS OF SPASTICITY IN UMN LESION
Upper limb Actions Muscles affected
Scapula Retraction, Downward rotation Rhomboids
Shoulder Adduction , internal rotation ,
depression
Pectoralis major, LD, Teres major,
Subscapularis
Elbow Flexion Biceps, Brachialis, Brachioradialis
Forearm Pronation Pronator teres, Pronator
Quadratus,
Wrist Flexion adduction Flexor Carpi radialis
Hand Finger flexion, clenched fist
thumb. Adducted in palm
FDP, FDS, Add Pollicis Brevis,
FPB

16. TYPICAL PATTERNS OF SPASTICITY IN UMN LESION
Lower limb Action Muscles affected
Pelvis Retraction Quadratus lumborum
Hip Adduction , Internal rotation,
extension
Add Longus/brevis, Add Magnus
Knee Extension Quadriceps
Foot and ankle PF, Inversion, Toes claw, Toes
curl
Gastroc soleus , Tibialis Posterior
,
Long toe flexors
Trunk Lateral flexion, rotation Rotators , internal /external
obliques

17. • Passive motion testing :
• Responsivness of muscle to stretch
• Patient is instructed to relax , maintain firm and constant
manual contact
• Normal tone- limb moves easily and therapist is able to alter
direction and speed without feeling abnormal resistance.
• Hypertonic muscle- stiff feeling, resistant to movement,
• Hypotonic mucscle- heavy feeling and unresponsive
• Increasing the speed of movement – increases the resistance
in case of hypertonic muscle.
• Clonus- maintained quick stretch stimulus
• Begin tone assessment with normal side
• Comparison between upper and lower limbs and also
between right and left side.

18. GRADING OF TONE
• 0-4+ scale
• 0- No Response (flaccidity)
• 1+ Decreased response (hypotonia)
• 2+ normal response
• 3+ Exaggerated response (Mild to moderate hypertonia)
• 4+ sustained response (Severe hypertonia)

19. MODIFIED ASHWORTH SCALE
• In case of Spasticity
• Subjective , 5 point ordinal scale,
• 0 No increase in muscle toone
• 1 Slight increase in muscle tone , manifested by catch and release or by
minimal resistance at the end of the ROM when the affected part is
moved inn flexion or extension
• 1+ Slight increase in muscle tone , menifested by catch , followed by
minimum resistance throughout the remainder (less than half) of the
ROM
• 2 more marked increase in muscle tone through most of the ROM , but
altered part is easily moved
• 3 Considerable increase in muscle tone, passive movement difficult
• 4 Affected part rigid in flexion and extension

20. • Pendulum test – with the patient seated in high sitting ,
patient’s knee is extended fully and allowed to drop
• A Normal and hypotonic limb – swings freely for several
oscillations
• Hypertonic Limb- resistant to the swinging motion and quickly
return to initial starting dependent position
• A myotonometer –
• handheld computerised electronic device
• Quantitative measurements of force and displacement of
muscle tissue

21. SUMMARY
• Introduction
• Abnormal Tone- Spasticity
Rigidity
Hypotonia
Dystonia
Decerebrate Rigidity
Decorticate Rigidity
• Examination of tone
• Modified Ashworth Scale

22. REFERENCE
• Physical Rehabilitation by Susan B O’Sullivan – 5th Edition