Muscle strength testing

Different methods of muscle strength testing both manual and instrumental.

1. MUSCLE STRENGTH
TESTING


By APOORVA VISHWANATH

2. WHAT IS MUSCLE STRENGTH ?


According to the AMERICAN COUNCIL
OF EXERCISE, muscular strength is the
maximal force a muscle or a muscle group
can exert during a contraction.


Factors related to muscle strength are:

 The size of the muscle fibers
 The ability of the nerves to activate the
muscle fibers

3. TERMS RELATED TO
MUSCLE STRENGTH

1. Power: The combination of muscular
force and speed of movement.

2. ENDURANCE: The ability of the muscles to
exert force against resistance over a
sustained period of time or
repetitions is known as muscular
endurance.

4. MUSCLE STRENGTH
TESTING


In muscle strength testing,
we assess the muscular

5. strength of patient as part of
the objective assessment.





PURPOSE:


1. DIAGNOSTIC

2. EXAMINE THE IMPROVEMENT OR
DETERIORATION IN A PATIENT’S
STATUS OVER TIME


3. DETERMINE THE EXTENT OF
STRENGTH LOSS

6. 4. DETERMINE THE NEED FOR
COMPENSATORY MEASURES


5. HELPS IN THE FORMATION OF A
TREATMENT PLAN


METHODS


Muscle strength can be assessed by
a number of methods:

1. MECHANICALLY OR
INSTRUMENTALLY

7. 2. MANUALLY





MECHANICAL OR
INSTRUMENTAL MUSCLE
TESTING

In this the following devices are
used to measure the strength
 CABLE TENSIOMETER
 STRAIN GAUGE

8.  HAND HELD DYNAMOMETER
OR GRIP STRENGTH
DYNAMOMETER
 MODIFIED
SPHYGMOMAMOMETER
 PINCH METER


CABLE TENSIOMETER

In cable tensiometer, two cables will be
there in which one end of the cable is
attached to some fixed or stable object and
the other end is attached to a limb segment.
As the cable is pulled, it presses the
tensiometer’s bar which is connected to the
gauge that measures in relative units.

11. STRAIN GAUGE

Strain gauges are made of electro
conductive material. Strain gauge
devices are less often used for muscle
evaluation.

12. The basic system FDM-T consists of an integrated, calibrated
measuring sensor. The sensor strain gauge element itself
consists of numerous high-quality capacitive force sensors.
On a treading area of 150 x 50 cm the sensor unit can bear
more than 5000 pressure / force sensor .

13. HAND HELD DYNAMOMETER OR
GRIP STRENGTH DYNAMOMETER

Mainly used for measuring strength of the
hand and forearm muscles.
Maximum grip strength is the measure of
three trails.

14. MODIFIED SPHYGOMAMOMETER


 Inflate the cuff up to 20mmHg
 Then squeeze the cuff and note the
readings

16. PINCH METER
This is used to assess strength of fingers.
1. TIP PINCH- thumb and index finger
2. LATERAL/KEY PINCH-thumb pad and lateral aspect of the index finger
3. PALMAR PINCH- thumb, index and middle finger


Average of 3 trials for each pinch position is taken.

17. MANUAL MUSCLE TESTING

Manual muscle testing is the most
popular way to test strength. The
therapist will push the body parts in
specific directions while the patient will
resist the pressure.
The Oxford scale OR MRC Scale is
commonly used by physiotherapists to
manually assess muscle strength.
According to the Oxford scale, muscle
strength is graded 0 to 5. The grades are
summarized below:

18. 0/5
A 0/5 score means that the patient is unable to create any
visible or noticeable contraction in a specific muscle. This
occurs when a muscle is paralyzed, such as after a stroke,
spinal cord injury, or cervical or lumbar radiculopathy.
Sometimes pain can prevent a muscle from contracting at
all.
1/5
A grade of 1/5 occurs when muscle contraction is noted
but no movement occurs. A small flicker of muscle
contraction may be palpated, or felt, during testing.
2/5
This muscle-strength grade is assigned when the muscle
can contract but cannot move the body part fully against
gravity. When gravity is reduced or eliminated during a
change in body position, the muscle is able to move the
body part through its full range of motion.

19. 3/5
A 3/5 grade means that the patient is able to fully
contract the muscle and move the body part through
its full range of motion against the force of gravity.
But when resistance is applied, the muscle is unable
to maintain the contraction.




4/5
A 4/5 grade indicates that the muscle is able to
contract and provide some resistance, but when the
therapist presses on the body part with maximum
force, the muscle is unable to maintain the
contraction.

20. 5/5
This means the muscle is functioning normally and
is able to maintain its position even when maximum
resistance is applied.
Occasionally the therapist may grade the muscle strength
in half increments, using the + or - sign. The use of these
incremental grades is subjective, which makes them
unreliable.
0 0 No visible or palpable contraction
Trace I 1 Visible or palpable contraction (No ROM)

Poor
-
2
-
Partial ROM, gravity eliminated
Poor II 2 Full ROM, gravity eliminated
Poor
+
2
+
Gravity eliminated/slight resistance or < 1/2 range against gravity

Fair
-
3
-
> 1/2 but < Full ROM, against gravity
Fair III 3 Full ROM against gravity
Fair
+ 3
+ Full ROM against gravity, slight resistance

Good
-
4
-
Full ROM against gravity, mild resistance
Good IV 4 Full ROM against gravity, moderate resistance
Good
+
4
+
Full ROM against gravity, almost full resistance

Normal V Normal, maximal resistance

21. RESISTED
ISOMETRIC
CONTRACTION

Isometric muscle testing is
commonly performed by therapists to
test the strength and determine
whether an injury or illness has
affected it. It can be used test the
strength and determine whether the
workout routine is effectively helping
you to get stronger.

22. Steps to perform resisted isometric
movements:
1. The joint is placed in a neutral or resting
position.
2. Then the patient is asked to perform
strong isometric contraction, not to move
the part and the therapist will resist with
almost equal amount of force to prevent
any movement from occurring and also to
ensure the patient exerts maximum force.

After the movements are performed,
the therapist determines the
contractile tissue affected by judging
the degree of pain and strength in
contraction.

23. 4 classic patterns according to pain and
strength are:

1.STRONG AND PAINFREE
There is no lesion in the contractile
tissue (muscle as well as nerve
supplying)
2. STRONG AND PAINFUL
There is a local lesion of muscle or
tendon. Muscle strain may be possible.
3. WEAK AND PAINFUL
Seen in severe lesion of muscle or tendon.
Muscle strain may be possible.
4. WEAK AND PAINFREE
Indicates complete rupture of muscle or
tendon or involvement of peripheral nerve
root supplying that muscle.

24. Thank you!