Muscle Power and Tone Examination

1. Examination of the
Motor System
In association with
Dr David Smith
Consultant Neurologist
Walton Centre for Neurology
and Neurosurgery
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK1
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK

2. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Note
This study guide is designed with
right-handed examiners in mind.
please substitute appropriately if left-
handed
Arrows on photographs depict the
direction of movement of the limb

3. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK3
CONTENTS
Tone and Clonus
Limb Power
Reflexes

4. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
The motor system
Messages travel from the motor cortex via subcortical
nuclei and brainstem to spinal cord, thence to
nerve roots, peripheral nerves and finally to
muscles
Upper Motor Neurone (UMN)
From the motor cortex to anterior horn cell of
the spinal cord
Lower Motor Neurone (LMN)
from anterior horn cell to neuromuscular
junction

5. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK5
Testing muscle
tone and
clonus

6. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Tone
NORMAL
passive movement of the limbs should be neither floppy
nor stiff
INCREASED due to -
lesions of pyramidal tract (UMN) –SPASTICITY
or lesions of the extrapyramidal tract –RIGIDITY
REDUCED
caused by LMN lesions, is called FLACCIDITY
Abnormal tone will be accompanied by other signs
which help to localise the lesion
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK6

7. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK7
Testing for spasticity in the arms 1
Support the elbow with your left
hand
Hold patient’s hand as if shaking
hands
Rapidly supinate and pronate the
arm
Use the same technique on each
arm
Always use the same hand to
assess movement for the patients
right and left

8. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK8
Testing for spasticity in the arms 2
While still supporting
the elbow passively
flex and extend the
elbow
Use same technique
on both arms
If tone is normal there
will be no resistance to
these movements

9. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK9
Testing for spasticity in the legs 1
With the patient relaxed, place your hands on the
thigh and roll the whole leg
Observe the movement of the foot
If tone is normal the range of movement of the foot
is similar to the rotation of the leg
Alternatively
Flex and extend the knee
If tone is normal there should be no resistance to
this movement

10. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10
Lower Limb Tone 2

11. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK11
Testing for spasticity in the legs 2
(Clonus)
Position the patient with the
knee flexed and the hip
externally rotated
Sharply dorsiflex the foot
In most people with normal
tone the foot will not move
But 2-3 beats of clonus
(plantar flexion followed by
dorsiflexion of the foot)
can be within normal limits
Sustained clonus is a
sign of an upper motor
neurone problem

12. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Pyramidal tract (UMN) lesion;
SPASTICITY
There is initial resistance to movement which
gives way as the movement continues
Arm; SUPINATOR CATCH
Leg; CLASP KNIFE phenomenon
There is usually SUSTAINED CLONUS
(>3-4 beats)
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK12

13. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK13
Testing Power

14. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK14
The grading of muscle power (MRC)GradeMeaning
0Complete paralysis
1Flicker of contraction possible
2Movement possible if gravity eliminated
3Movement against gravity but not resistance
4Movement possible against some resistance
5Power normal (it is not normally possible to
overcome a normal adult’s power)
6

15. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Patterns of weakness 1
Help to localise the problem within the
nervous system
A limited examination allows you to
differentiate between UMN and LMN lesions
Different patterns of LMN weakness may
require more detailed examination
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK15

16. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Motor power
Ask the patient to make the required
movement
Attempt to overcome the movement
remembering that this is not a test of relative
strength
Avoid mechanical advantage to the examiner
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK16

17. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK17
Summary of motor supply to the upper limb
Extension
C7/8
Flexion
C5/6
Extension
C7/8
Flexion
C6/7
Extension
C7/8
Flexion
C7/8
Abduction
C5/6 Adduction
C6/7/8
Adduction
C8/T1

18. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK18
Shoulder abduction (C5/6) and adduction
(C6/7/8)
Position patient with shoulders
abducted to 90°
Ask patient to maintain position
whilst you attempt to overcome by
pressing down on upper arm
Position patient with arms at approx
30°of abduction, with elbows
flexed
Ask patient to bring elbows
towards side against resistance
“Stop me
pushing your
arms down”
“Stop me
pushing your
arms up”

19. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK19
Elbow flexion 2
(C5/6) and extension (C7/8)
Position patient with elbow
flexed
Ask them to resist your attempt
to straighten arm
Position patient with elbow
extended beyond 90 °
Ask them to resist your attempt
to flex the elbow (‘push me
away’)
“Pull me towards you”
“Push me away”

20. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK20
Finger extension (C7, C8)
Position patient with
fingers extended
While supporting wrist
ask them to resist your
attempt to flex fingers
“Stop me trying to
bend your fingers
down”

21. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Finger flexion
Ask patient to curl fingers
towards palm
And to keep fingers flexed
while you attempt to
straighten them
Alternatively
ask them to squeeze two of
your fingers placed in
either of the patient’s palms
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK21
“Stop me
pulling
your
fingers
straight”
“Squeeze
my fingers”

22. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK22
Summary of lower limb motor supply
Abduction
L4/5/S1
Adduction
L2/3/4
Inversion
L5/S1
Eversion
L5/S1
Extension
L3/4
Flexion
L2/3Extension
L5/S1/2
Dorsiflexion
L4
Plantar flexion
S1/S2
Flexion
L5/S1

23. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK23
Hip flexion (L2/3) and extension (L5/S1/2)
Position the patient with the leg
elevated to approx 30°
Attempt to overcome by
pressing down on thigh
Position patient with leg flat on
couch
Place your hand underneath
thigh and attempt to elevate
leg while patient presses
down
“Stop me
trying to raise
your leg up”
“Stop me
pushing your
leg down”

24. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Knee flexion (L5/S1)
Position patient seated with knee flexed
Place your left hand on patient’s thigh
Place your right hand behind heel/ankle/calf
Ask patient to bring heel towards buttocks against
resistance
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK24
“Stop me trying to straighten your leg”

25. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Knee extension (L3/4)
Position patient seated
with knee flexed
Place your left hand on
patient’s thigh
Place your right hand
over patient’s shin
Ask patient to
straighten leg against
resistance
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK25
“Stop me trying to bend your
knee”

26. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK26
Dorsiflexion (L4) and plantar flexion (S1/2) of the foot
Dorsiflexion: Ask patient
to bring foot upwards
Attempt to overcome by
pressing down on foot
Plantar flexion: Ask
patient to push foot down
Attempt to overcome by
pressing upwards on sole
“Stop me pushing your
foot down”
“Stop me pushing your
foot up”

27. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Patterns of weakness 2
UMN lesion
there is weakness of the;
extensorsin the arms
flexorsin the legs
The unopposed action of unaffected muscles produces the
characteristic posture seen in patients with stroke
LMN lesion
involvement of nerve endings (peripheral
neuropathy) produces a predominantly distal
pattern of weakness
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK27

28. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK28
Testing the
reflexes

29. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK29
Reflexes
Normal reflex arc requires :-
Stimulus to stretch receptors
Intact sensory afferent pathway
Link with a motor unit
Intact motor neurone
Contractile element
The order in which you test reflexes should be logical
and may vary from one examiner to another
The patient must be relaxed

30. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Documenting reflexes
Absent -
Present with reinforcement +/-
Normal +or ++
Brisk +++
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK30
Reflexes can be recorded as follows:

31. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK31
The reflexes
Biceps (C5/6)
Triceps (C7/8)
Supinator
(C5/6)
Finger (C8)
Ankle (S1/2)
Plantar (L5/S1/2)
Knee (L3/4)
Abdominal

32. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Testing for reflexes
Position the limb correctly
Hold the tendon hammer like a hammer
Place your finger over the tendon and strike it,
for some reflexes you will strike the tendon itself (see
slides below)
(except the ankle –see slide 38)
Observe the relevant muscle for contraction
(not the limb movement)
Be aware of the range of normality.
Abnormal reflexes rarely seen without other relevant
signs
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK32

33. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK33
Reinforcement
Where a reflex appears difficult
to elicit, reinforcement might
be tried.
Ask the patient to close their
eyes:
lower limb
ask the patient to grasp the
fingers of each hand and to
pull apart on instruction just as
the reflex is tested
upper limb
the teeth may be clenched
Reinforcement for a lower limb
reflex –with patient’s eyes
closed

34. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK34
The upper limb
Reflex Testing

35. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK35
Supinator (brachioradialis) reflex (C5/6)
Position patient sitting
relaxed, with elbows
flexed and hands
resting on thigh/groin
Place your left
index/middle finger(s)
over supinator tendon
Strike finger(s) with
falling head of hammer
Observe slight elbow
flexion or contraction of
belly of brachioradialis
Observe for contraction of
brachioradialishere
You may notice momentary
elbow flexion

36. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK36
Biceps reflex (C5/6)
In same position clasp
patient’s elbow so that
biceps tendon can be felt
under your thumb or finger
Strike your thumb or finger
Observe elbow flexion
there may be little movement
but you should feel the
contraction

37. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK37
Triceps reflex (C7/8)
Position patient with their
arm across the
abdomen with elbow
flexed to 90°
Strike the triceps
tendon direct
Observe
for elbow extension
or contraction of the
muscle belly
You may feel muscle contract
with free hand

38. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK38
The finger jerk (C8)
Ask patient to rest their
fingers on index and middle
fingers of your left hand and
curl their fingers slightly
Strike your fingers
Patient’s fingers may flex
This can be normal

39. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK39
The lower limb
Reflex Testing

40. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK40
Knee reflex (L3/4)
Support one or both
knees, so they are
slightlybent
Strike the patellar
tendon direct
Observe
quadriceps contraction
with or without knee
extension
Infrapatellar ligament
Patella

41. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK41
Ankle reflex S1/2
Patient is seated
Place your left hand on
ball of patient's foot
Passively dorsiflex the
ankle
Strike your fingers
Observe/feel for
plantarflexion

42. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK42
Plantar reflex (L5/S1/2)
Patient seated with leg
flat on couch
Drag thumbnail or
blunt object along the
lateral border of the
foot and across the
sole towards other side
The normal response is
flexion of the big toe
may be absent if feet
are cold

43. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Patterns of reflex change
UMN lesion
Reflexes brisk below the level of the lesion
plantar response is usually extensor
A pathologically brisk finger flexion jerk is the
upper limb equivalent of an extensor plantar
response
LMN lesion (peripheral neuropathy)
reflexes are absent
distal reflexes are first to be lost
10/13/2011 43

44. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Summary
Parameter UMN lesion LMN lesion (peripheral
neuropathy)*
Posture Flexed UL, ExtendedLL Maybe wasting,
fasciculation
Tone Increased (spasticity)Reduced (flaccidity)
Power Weakness of UL
extensors and LL flexors
Distal weakness
Reflexes Brisk Absent
Plantar response Extensor Flexor or absent
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK44
There are other patterns of lower motor neurone
lesions (nerve root, individual peripheral nerve).*

45. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Reminder
What you have learned so far will allow you
to distinguish between UMN and LMN
lesions
In future you will learn additional skills
needed to localise lesions according to
particular presentations
E.g. examination of the intrinsic hand muscles
in someone with weakness or tingling in the
hand/fingers.
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK45

46. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Finger abduction
Support patient’s wrist with your
left hand
Ask patient to spread fingers
wide
Ask patient to maintain this
position while you try to push
little finger inwards
Ask patient to maintain this
position while you try to push
index finger inwards
10/13/2011 46
“Stop me pushing your
fingers”

47. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Thumb abduction (T1, median)
Support patient’s wrist
with your left hand
Ask patient to lift
thumb upwards
Ask them to maintain
that position against
resistance
10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK47
“Stop me pushing your thumb
down to your palm”
Thumb abduction is 90°to finger abduction

48. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Thumb opposition (T1,Median)
Support patient’s wrist
with left hand
Ask patient to place tip
of thumb onto tip of
index finger
And to hold this
position while you try to
separate the thumb
and index finger
48
“Stop me pulling your fingers
apart”

49. 10/13/2011 © Clinical Skills Resource Centre, University of Liverpool, UK
Thumb adduction (T1, Ulnar)
Support patient’s wrist
with your left hand
Ask patient to trap your
index and middle
fingers between the
base of their thumb
and their index finger
Ask them to maintain
that position while you
try to lift their thumb
10/13/2011 49
“Stop me trying to lift your
thumb up”