Examination of The Motor System

And The Sensory System

SEMINAR by : ABHILASH DASHEmail ID : physio.abhilash@gmail.com

1. Muscle bulk

2. Muscle tone

3. Muscle power

4. Examination of sensory system

5. Sensory dermatome

6. Myotome

7. Difference between cerebellar and sensory ataxia

8. Reference

THE MOTOR SYSTEM

The following aspects are examined under motor system

1. Muscle bulk

2. Muscle tone

3. Muscle power, strength

4. Involuntary movement

5. Reflexes

6. Coordination of movement

1. Muscle bulkBulk of muscle is assessed by

Inspection

Palpation

Measurement

INSPECTIONParts like face, neck, shoulder girdle, pelvic girdle, distal part of limbs are

exposed and look for wasting of muscle.

If there is wasting, find out whether it is localised to

• One muscle

• Group of muscles

• Segment

• Whole limb

Features of wasted muscle/ atrophic muscle

• Smaller in size

• Soft than normal when they are contract.

• When fibrosis occurs they feel hard and inelastic.

• Long term atrophy cause contracture.

Palpation• Normal muscle is semielastic to feel.

• Atrophy muscle are soft initially, later the fibrosis occurs and it feels firm.

• Rubbery or doughy consistency occurs in pseudohypertrophy. The

pseudohypertrophy are weak.

Measurement• Expose the limbs and kept them in identical position.

• Measure the circumflex of limbs by measuring tape.

2. Muscle tone Defined as the degree of tension present in a muscle at rest.

LOSS OF TONE:- Muscles are lax; they assume a pendulous shape when allowed to

hang freely, diminished resistance to passive movement and so widen range of

movement, difficulty in positioning the limb.

Tendon reflex are decreased or absent.

Cause- AHC disease, peripheral nerve injury, cord or root compression, myasthenia

gravis, myopathies, cerebellar lesion, chorea, neurological shock.

INCREASE OF TONE-i) Spastic type-

Tone and resistance are greater in one group of muscle than antagonist.

Also called clasp knife effect mostly seen at elbow and knee joint.

This is the sign of UMN lesion, pyramidal pathway lesion. Here the hypotonicity is

more severe in flexor and extensor of upper limb and adductors of lower limb.

ii) Plastic type-

Equal resistance in both agonist and antagonist at any point so same degree of

hypertonicity is felt throughout the movement.

So called spastic or lead pipe rigidity.

When it becomes very marked, a state of true rigidity seen which hold the limb

complete immobility.

It is seen in extreme spasticity from UMN lesion, is a characteristic feature of a

lesion of extrapyramidal system, parkinsonism.

iii) Cog wheel rigidity-

In this type agonist and antagonist contract alternately, rapidly, regularly during

the movement.

So called cog wheel rigidity.

This only present during fast moment of testing.

This is a sign of extrapyramidal disease.

iv) Paratonia-

In this type when a patient is asked to relax a joint to allow movement, the

involved muscle involuntarily contract instead, and patient appears to be actively

opposing any movement of the joint by the examiner.

It is generally seen in diffuse frontal lobe disease.

CLONUS Sudden stretching of hypertonic muscle produce reflex contraction.

If the stretch is maintained during subsequent relaxation, further reflex

contraction occur and this may continue almost indefinitely, unless the stress

stimulus released.

It is mainly seen in tense patient, reflex excitability , once who has an fright (

ankle clonus in drivers), or it maybe a symptom of same side pyramidal lesion on

that side.

MYOTONIA Muscle contraction continues beyond the period of time required for the

particular movement.

MODIFIED ASHWORTH SCALE (MAS)

o MAS is considered the primary clinical measure of muscle spasticity in patient with

neurological condition.

o Examiner passively flex or extend the limb and feel the spasticity.

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 range of motion 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.

3. Muscle power

Power is tested in a proximal to distal direction comparing sides with the patient

in the seated position for the upper limbs and the lying position for the lower

limbs.

This is done by the examiner stabilizing the limb proximal to the joint where the

movement is being tested and then passively resisting the movement.

GRADING OF POWER0 = No movement.

1 = flicker contraction but no movement.

2 = available full range of motion when the gravity is eliminated.

3 = available full range of motion against gravity but not against resistance.

4 = available full range of motion against moderate resistance with against gravity.

5 = normal power.

Serratus Anterior Biceps brachaii

Brachioredialis

Triceps

Deltoid

Extensor Digitorium Gluteus Maximus

Hamstrings

Quadriceps femoris

Peronei

illipsoas

Adductor muscle

Tibialis posterior

Tibialis anterior

Flexor digitorium

Extensor digitorium

MYASTHENIA

o This is the type of muscle weakness seen in myasthenia gravis, where the

degree of weakness varies from hour to hour, increase as the muscle is

repeatedly used, even to the extent of total paralysis and yet recover to its

previous condition after a very short period of rest.

o This phenomenon commonly seen in the eyelids, the external occular muscles,

the facial muscles of tongue, throat and larynx, the muscles of back, shoulder

girdle and hand.

THE SENSORY SYSTEM

Modalities of sensation to be tested-

Exteroceptive sensation like- Pain, Light touch, Temperature.

Propreoceptive sensation like – Sense of position, Passive movement,

Vibration and Deep pain .

Cortical sensation like- Stereognesis, Graphaesthesia, Two point

discrimination.

PAIN• Patient’s eye is closed.

• Use a Safety pin for demonstrating sharp pain.

• Avoid skin penetration and injury .

• Stimulus of same intensity is used each time.

• Start distally and move proximally.

• Aim is to test each dermatome and nerve.

• Ask him to say whether it is sharp and painful quality or touch.

LIGHT TOUCH• Show the patient what you are going to do – touching an area with cotton and he

should say yes every time he touch and whether the perceive sensation is normal

or alter.

• Patients eye are closed.

• Compare each side of symmetry start from the area of alter sensation.

• Remember the dermatome while doing test.

• Ask whether you are touching right, left, or both simultaneously.

TEMPERATURE• Use test tube filled with water maintained at 50ºC for hot and 5ºC for cold

sensation to be tested.

• Ask the patient to close his eyes and place the test tube in random order at

random location over the skin and ask him to identify whether it is hot or cold

sensation.

Proprioception• Eye closed.

• Big toe/ thumb is tested initially.

• Fix the distal interphalengial joint of patient’s thumb or big toe by holding it

on medial and lateral aspect. With the finger and thumb of your other hand

hold the medial and lateral aspect of thumb or toe and move it slightly up and

down randomly, and then hold it in one position.(up or down). Ask the patient

which position the joint is in.

• Start with larger movements gradually reduce the amplitude in order to detect

range of movement that can be appreciated.

• Ask him whether he is appreciating the direction of movement and he should

say whether it is up or down each time a movement is made.

• Movements of less than 10 degree can be appreciated at all normal joint.

• Sensation can also be treated by keeping one limb in one particular position

and asking the patient to keep the opposite limb in the same position with

closed eyes.

Proprioception signs

Romberg’s sign Asses the position sense.

The patient stand his both feet together. Ask to close eyes and note whether he

sways i.e., unable to maintain stand.

Barre’s sign (pronator drift) Ask the patient to hold both arms out stretched, symmetrically in front with palms

facing upwards and eyes closed.

Then palm goes to pronation state called pronator drift.

This indicate contralateral cerebral lesion.

Pseudoarthetosis

Patient has his arms outstretched and eye closed.

If position sense is disturbed on upper limb the finger move up and down

or to the side(piano playing movement).

This involuntary movement is pseudoarthetosis, which does not occur if

the eyes are open.

Romberg test

Pronator draft

VIBRATION• Patient eyes are closed.

• Place a vibrating tuning fork over the bony point and ask the patient whether he

can feel the vibration ( not the cold feel or the weight of fork).

• Start peripherally and distal phalanx of big toe and distal phalanx in upper limb

and move over the bony prominence like clavicle, tibial tubercity, internal

malleolus, lower end of radious, ASIS and ribs.

• Ask him to say when the vibration stops. At this point if the examiner is able to

perceive the vibration. That means patient vibration sense is impaired.

GRAPHAESTHESIA• Ability to recognise letters or numbers written on skin with a blunt point.

• With patient eye closed, the examiner write single numbers or letters on the

palm, anterior aspect of forearm, thigh or leg.

• Clear figure like 8, 4, 5 are used at first.

• Figure should be more than 4 cm

• Patient is asked to identify what is being written .

• The test is the similarly repeated on other palm.

• Need not test on feet.

• **When the peripheral sensation is normal and there is agraphesthesia, it indicates

contralateral parietal lesion.

STEREOGNOSIS• Ability to recognise and identify object purely from the feel of its shape and size.

• The patient close his eyes.

• Explain the patient that an object will be place in hand and by feeling it, he has

to be identify the object.

• Familiar, easy identifiable objects like a key, pain, coin of variable size etc. placed

in his hand.

• If he fail the objet is placed in other hand and comparison made both for accuracy

and speed of response.

TWO POINT DISCRIMINATION• Ability to recognise two point applied simultaneously on skin by two object.

• Use a compass .

• Demonstrate to the patient the difference between one point and two point

stimulation.

• With eye closed apply two point simultaneously in the areas like lips(2-3 mm),

dorsum of hand

• (2-3 cm), finger tip(3-5mm) and dorsum of foot(3-4 cm).

SENSORY INATTENTION• It is inability to perceive simultaneously applied stimulus as two.

• If the patient with eye closed, can feel the touch on each side independently, then

touch him on both sides simultaneously.

• If he is recognising the touch only on the side it is sensory inattention.

SENSORY DERMATOME Area of skin supplied by a single spinal segment is called Dermatome.

Patient consider to be standing with the palms of the hand facing forward.

C1 gives no supply to skin,

C2 supply to occiput

C5 supply the outer aspect of shoulder tip

C7 supply the middle finger

T2 lies in apex of axilla

T6 intersection of midclavicular line and horizontal level of the xiphoid process.

T10 supplies intersection of midclavicular line at the horizontal level of the

umbilicus.

T12 lies au inguinal ligament.

L3 lies at the medial epicondyle of femur

L4- over medial malleolus

L5 runs diagonally from outer aspect of tibia to inner aspect of foot

S1 supplies on the lateral aspect of calcaneus

S2- midpoint of popliteal fossa

S3 S4 S5 are in concentric rings around the ramus

MYOTOME Spinal segments supplying skeletal muscle called Myotome.

A myotome is the group of muscles that a single spinal nerve root innervates.

C1/C2-Neck Flexion/ Extension

C4- Shoulder Elevation

C5- Shoulder Abduction

C6- Elbow Flexion/ Wrist Extension

C7- Elbow Extension/ Wrist Flexion/ Finger Extension

C8- Finger Flexion

T1- Finger Abduction

L2- Hip Flexion

L3- Knee Extension

L4- Ankle Dorsi-flexion

L5- Great Toe Extension

S1- Ankle Plantar Flexion/ Ankle Eversion/ Hip Extension

S2- Knee Flexion

Clinical importance:-

o Testing myotome in the form of isometric resisted muscle testing, provide the

clinician with information about the level in the spine where a lesion maybe

present.

o During myotome testing the clinician is looking for muscle weakness of a particular

group of muscle. Results may indicate lesion to the spinal cord nerve root, or

intervertebral disc herniation pressing on the spinal nerve roots.

References

1. BICKERSTAFF ’s Neurological Examination by KAMESHWAR PRASAD

2. Neurological Assessment by RUBEN D. RESTREPO

3. Neurological Examination by WILLIAM HOWLETT

4. Neurological intervention for Physical Therapy by MARTIN KESSLER

5. A Concise Guide to Neurology by REMA PAI

6. Neurology Illustrated by KENNETH W LINDSAY, IAN BONE

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