This PPT is contains the valuable information related to the tone of the muscle.This PPT is made up from the book physical rehabilitation by o sullivan.

1. DISORDERS OF THE
TONE
-Hitesh Rohit (3rd year
B.P.T.)

2. INTRODUCTION:-
• Tone:-
• Tone is defined as the resistance of muscle to passive
elongation or stretch.
• It represents a state of slight residual contraction in normally
innervated, resting muscle, or steady-state contraction.
• Tone is influenced by a number of factors, including
• (1) physical inertia,
• (2) intrinsic mechanical-elastic stiffness of muscle and
connective tissues,and
• (3) spinal reflex muscle contraction (tonic stretch reflexes).

3. • Tonal abnormalities are categorized as hypertonia (increased
above normal resting levels),
• hypotonia (decreased below normal resting levels),
• Or dystonia(impaired or disordered tonicity).

4. HYPERTONIA :-
• 1) spasticity :-
• Spasticity is a motor disorder characterized by a velocity
dependent increase in muscle tone with increased
resistance to stretch;
• The larger and quicker the stretch, the stronger the
resistance of the spastic muscle.
• During rapid movement, initial high resistance (spastic
catch May be followed by a sudden inhibition or letting go
of the limb (relaxation) in response to a stretch
stimulus,termed “clasp-knife response”.

7. • Chronic spasticity is associated with contracture, abnormal
posturing and deformity, functional limitations, and
disability.
• Spasticity arises from injury to descending motor pathways
from the cortex (pyramidal tracts) or brainstem (medial
and lateral vestibulospinal tracts, dorsal reticulospinal
tract) producing disinhibition of spinal reflexes with
hyperactive tonic stretch reflexes or a failure of reciprocal
inhibition.(hyperreflexia)

8. • The result is hyperexcitability of the alpha motor neuron
pool. It occurs as part of upper motor neuron (UMN)
syndrome.
• Increased tonic contraction of muscles is seen at rest,
evidenced by abnormal typical resting postures.When
movementsts are attempted, the result is action-induced
normal movement patterns (stereotyped movement
synergies or spastic dystonia).

11. • Additional signs include associated reactions, defined as
involuntary movements resulting from activity occurring in
other parts of the body (e.g., sneezing, yawning, squeezing
the hand).
• Clonus is characterized by cyclical, spasmodic alternation of
muscular contraction and relaxation in response to
sustained stretch of a spastic muscle.
• Clonus is common in the plantarflexors, but may also occur
in other areas of the body such as the jaw or wrist.

13. • 2) Rigidity:-
• Rigidity is a hypertonic state characterized by constant
resistance throughout ROM that is independent of the
velocity of movement (lead-pipe rigidity).
• It is associated with lesions of the basal ganglia system
(extrapyramidal syndromes) and is seen in Parkinson’s
disease.
• Rigidity is the result of excessive supraspinal drive (upper
motor neuron facilitation) acting on alpha motor neurons;

14. • spinal reflex mechanisms are typically normal.
• Patients demonstrate stiffness, inflexibility, and significant
functional limitation.
• Cogwheel rigidity refers to a hypertonic state with superimposed
ratchet-like jerkiness and is commonly seen in upper extremity
movements (e.g., wrist or elbow flexion and extension) in
patients with Parkinson’s disease.
• It may represent the presence of tremor superimposed on
rigidity.
• Tremor, bradykinesia, and loss of postural stability are also
associated motor deficits in patients with Parkinson’s disease.

16. • 3) Decorticate and Decerebrate Rigidity :-
• Severe brain injury can result in coma with decorticate or
decerebrate rigidity.
• Decorticate rigidity refers to sustained contraction and
posturing of the upper limbs in flexion and the lower limbs
in extension.
• The elbows,wrists, and fingers are held in flexion with
shoulders adducted tightly to the sides while the legs are
held in extension, internal rotation, and plantarflexion.

18. • Decerebrate rigidity (abnormal extensor response) refers to
sustained contraction and posturing of the trunk and limbs in a
position of full extension.
• The elbows are extended with shoulders adducted, forearms
pronated,and wrist and fingers flexed. The legs are held in stiff
extension with plantarflexion.
• Decorticate rigidity is indicative of a corticospinal tract lesion
at the level of diencephalon (above the superior colliculus),
whereas decerebrate rigidity indicates a corticospinal lesion in
the brainstem between the superior colliculus and vestibular
nucleus.

19. • Opisthotonus is characterized by strong and sustained
contraction of the extensor muscles of the neck and trunk,
resulting in a rigid, hyperextended posture.
• Extensor muscles of the proximal limbs may also be
involved. These postures are considered exaggerated and
severe forms of spasticity.

21. • 4)Dystonia :-
• Dystonia is a prolonged involuntary movement disorder
characterized by twisting or writhing repetitive movements
and increased muscular tone.
• Dystonic posturing refers to sustained abnormal postures
caused by cocontraction of muscles that may last for several
minutes, for hours, or permanently.
• Dystonia results from a CNS lesion commonly in the basal
ganglia and can be inherited (primary idiopathic dystonia),
associated with neurodegenerative disorders (Wilson’s
disease, Parkinson’s disease on excessive l-dopa therapy),
or metabolic disorders (amino acid or lipid disorders).

22. • Dystonia can affect only one part of the body (focal
dystonia) as seen in spasmodic torticollis (wry neck) or
isolated writer’s cramp.
• Segmental dystonia affects two or more adjacent areas(e.g.,
torticollis and dystonic posturing of the arm)

24. HYPOTONIA:-
• Hypotonia and flaccidity are the terms used to define
decreased or absent muscular tone.
• Resistance to passive movement is diminished, stretch
reflexes are dampened or absent, and limbs are easily
moved (floppy).
• Hyperextensibility of joints is common.
• Lower motor neuron(LMN) syndrome results from lesions
that affect the anterior horn cell and peripheral nerve (e.g.,
peripheral neuropathy, cauda equina lesion, radiculopathy).

25. • It produces symptoms of decreased or absent tone,
decreased or absent reflexes, paresis, muscle fasciculations
and fibrillations with denervation, and neurogenic atrophy.
• Mild decreases in tone along with asthenia (weakness)can
also be seen in cerebellar lesions.
• Acute UMN lesions(e.g., hemiplegia, tetraplegia, paraplegia)
can produce temporary hypotonia, termed spinal shock or
cerebral shock depending on the location of the lesion.

26. • The duration of CNS depression and hypotonia that occurs
with shock is highly variable, lasting days or weeks.
• It is typically followed by the development of spasticity an
classic UMN signs.

27. Examination of tone :-
• An examination of tone consists of :-
• (1) initial observation of resting posture and palpation,
• (2) passive motion testing, and
• (3) active motion testing.
• Variability of tone is common. For example, patients with
spasticity can vary in their presentation from morning to
afternoon, day to day, or even hour to hour depending on a
number of factors, including
• (1) volitional effort and movement,
• (2) anxiety and pain,

28. • (3) Position and interaction of tonic reflexes,
• (4) medications,
• (5) general health,
• (6) ambient temperature, and
• (7) state of CNS arousal or alertness
• In addition, urinary bladder status(full or empty), fever and
infection, and metabolic and/or electrolyte imbalance can
also influence tone.

29. • 1)Initial observation:-
• Initial observation of the patient can reveal abnormal
posturing of the limbs or body. Careful inspection should be
made regarding the position of the limbs,trunk, and head.
• With spasticity, posturing in fixed,antigravity positions is
common;
• for example, a spastic upper extremity is typically held
fixed against the body with the shoulder adducted, elbow
flexed, forearm supinated with wrist/fingers flexed.

30. • In the supine position, the lower extremities are typically held
in extension, adduction with plantarflexion, and inversion.
• Limbs that appear floppy and lifeless(e.g., a lower extremity
[LE] rolled out to the side in external rotation) may indicate
hypotonicity.
• Palpation of the muscle belly may yield additional information
about the resting state of muscle.
• Hypotonic muscles will feel soft and flabby, whereas
hypertonic muscles will feel taut and harder than normal.

31. • 2)Passive motion testing :-
• Passive motion testing reveals information about the
responsiveness of muscles to stretch.
• Because these responses should be examined in the absence of
voluntary control, the patient is instructed to relax, letting the
therapist support and move the limb.
• During a passive motion test, the therapist should maintain firm
and constant manual contact, moving the limb in all motions.
• When tone is normal, the limb moves easily and the therapist is
able to alter direction and speed without feeling abnormal
resistance.

32. • The limb is responsive and feels light. Hypertonic limbs
generally feel stiff and resistant to movement, whereas flaccid
limbs feel heavy and unresponsive.
• Some older adults may find it difficult to relax; their stiffness
should not be mistaken for hypertonicity.
• Varying the speed of movement is an important determinant of
spasticity. In a spastic limb, resistance may be near normal
when the limb is moved at a slow velocity. Faster movements
intensify the resistance to passive motion.

33. • It is also important to remember that muscle stiffness with
spasticity will offer the greatest resistance during the first
stretch and that with each successive stretch resistance can
be reduced by as much as 20% to 60%.
• In the patient with rigidity, resistance is constant and not
responsive to increasing the velocity of passive motion.
• Clonus, a phasic stretch response, is examined using a quick
stretch stimulus that is then maintained. For example, ankle
clonus is tested by sudden dorsiflexion of the foot and
maintaining the foot in dorsiflexion.
• The presencee of a clasp-knife response should also be
noted.

34. • All limbs and body segments are examined, with particular
attention given to those identified as problematic in the
initial observation.
• Comparisons should be made between upper and lower
limbs and right and left extremities.
• Asymmetrical tonal abnormalities are always indicative of
neurological dysfunction.
• A subjective determination of the degree of tone can be
made.

35. • Therapists need to be familiar with the wide range of normal
and abnormal tonal responses to develop an appropriate frame
of reference to grade tone.
• For documentation in the medical record, tone is typically
graded on a 0 to 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)

36. Modified Ashworth Scale :-
The Modified Ashworth Scale (MAS) is a clinical scale
used to assess muscle spasticity that is in commonly used
in many rehabilitation facilities and spasticity clinics.

37. Grade Description
0 No increase in muscle tone.
1 Slight increase in muscle tone, manifested by a
catch and release or by minimal resistance at the
end of the ROM when the affected part(s) is moved
in flexion or extension.
1+ Slight increase in muscle tone, manifested by a
catch, followed by minimal resistance throughout
the remainder (less than half) of the ROM.
2 More marked increase in muscle tone through
most of the ROM, but affected part(s) easily moved.
3 Considerable increase in muscle tone, passive
movement difficult.
4 Affected part(s) rigid in flexion or extension.

38. Special tests :-
In the lower limbs, spasticity can be examined using the
pendulum test.
The patient is positioned in supine with Knees flexed over the
end of a table.
The examiner passively extends the knee fully against gravity
and then allows the leg to drop and swing like a pendulum.
A normal and hypotonic limb will swing freely for several
oscillations.

39. • In patients with quadriceps or hamstring spasticity, the leg
is resistant to full extension and when dropped swings for
only a few repetitions.
• It quickly returns to the initial dependent starting position.
• Tonic stretch reflexes can be accurately measured using
electromyography (EMG).
• Response to stretch can be documented for various
velocities of stretch and spastic co-contraction can be
quantified.

40. • A myotonometer is a handheld computerized electronic
device developed by Leonard and co-workers that can be
used to measure muscle tone.
• It provides quantitative measurements of force and
displacement of muscle tissue and is able to detect small
changes in both extremity and postural tone

41. • Documentation:-
• Documentation of tone abnormalities should include a
determination of the specific body segments
demonstrating:-
• abnormal tone, the type of abnormality present (e.g.,
spasticity, rigidity), whether the changes are symmetrical
or asymmetrical, resting postures and associated signs (e.g.,
UMN syndrome), and factors that modify (increase or
diminish) tone

42. • It is important to remember that measurement of tone in
one position does not mean that tone will be the same in
other positions or during functional activities.
• A change in position such as sitting up or standing up can
substantially alter the requirements for postural tone.