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LECTURE IV
MANUAL MUSCLE TESTING
DR. AMAL HM IBRAHIM PROFESSOR OF PHYSICAL THERAPY
MANUAL MUSCLE TESTING
The ward “strength” has multiple meanings
within the profession of physical therapy.
These multiple meaning have caused difficulty
in communication, and led to opposing
conclusions among clinicians concerning a
patient’s functional ability.
MANUAL MUSCLE TESTING
Manual muscle test is one method by which
muscle strength is defined and measured.
History of manual muscle testing (Robert W.
Lovett 1912).
MMT uses the principles of gravity and applied
external load to determine the ability of a
patient to develop muscle tension voluntarily.
MANUAL MUSCLE TESTING
MMT must reflect the function of the
neuromuscular system.
MMT has been and still is considered
a useful diagnostic and prognostic
tool that can be used to judge the
effectiveness of therapeutic
programs.
PRINCIPLES OF MMT
The Guide to Physical Therapist Practice lists both manual
muscle testing (MMT) and dynamometry as appropriate
measures of muscle strength.
Manual muscle testing is a procedure for the evaluation
of the function and strength of individual muscles and
muscle groups based on the effective performance of a
movement in relation to the forces of gravity and manual
resistance.[2]
Dynamometry is a method of strength testing using
sophisticated strength measuring devices (e.g., hand-grip,
hand-held, fixed, and isokinetic dynamometry).
PRINCIPLES OF MMT
Muscle strength is the ability of
muscle to develop tension
through its long axis.
Muscle tension can be resolved
into two forces, one acting along
the long axis of the bone upon
which the muscle functionally
insert, and the other
perpendicular to that axis.
1- Stabilizing force.
2- Rotating force.
PRINCIPLES OF MMT
The muscle torque
must overcome the
torque created by the
weight of the
extremity and any
applied force in order
to move or maintain
the position of body
segment.
PRINCIPLES OF MMT
For grading strength there are three factors:
1- The extent of the arc of movement.
2- The gravity.
3- The amount of force applied by examiner
in a direction opposite to the torque exerted
by the muscle group being tested.
Some times the effect of gravity on the
segment cannot obtained.
PRINCIPLES OF MMT Medical
Research
Council
Daniels and
Worthingham
Kendall and
McCreary
Explanation
5 Normal(N) 100% Holds test position against maximal resistance
4+ Good + (G+) Holds test position against moderate to strong
pressure
4 Good(G) 80% Holds test position against moderate resistance
4- Good – (G-) Holds test position against slight to moderate
pressure
3+ Fair + (F+) Holds test position against slight resistance
3 Fair (F) 50% Holds test position against gravity
3- Fair- (F-) Gradual release from test position
2+ Poor + (P+) Moves through partial ROM against gravity OR
Moves through complete ROM gravity eliminated
and holds against pressure
2 Poor(P) 20% Able to move through full ROM gravity eliminated
2- Poor – (P-) Moves through partial ROM gravity eliminated
PRINCIPLES OF MMT
In the Medical Research Council scale, the
grades of 0, 1, and 2 are tested in the gravity-
minimized position (contraction is
perpendicular to the gravitational force). All
other grades are tested in the anti-gravity
position. The Daniels and Worthingham grading
system is considered the more functional of the
three grading systems outlined in Table 1
because it tests a motion that utilizes all of the
agonists and synergists involved in the motion
PRINCIPLES OF MMT
The Kendall and McCreary approach is designed to
test a specific muscle rather than the motion, and
requires both selective recruitment of a muscle by
the patient and a sound knowledge of anatomy and
kinesiology on the part of the clinician to determine
the correct alignment of the muscle fibers.[3]
Choosing a particular grading system is based on skill
level of the clinician while ensuring consistency for
each patient, so that coworkers who may be re-
examining the patient are using the same testing
methods.
PRINCIPLES OF MMT
It must be remembered that the grades obtained
with MMT are largely subjective and depend on a
number of factors including the effect of gravity,
the manual force used by the clinician, the
patient's age, the extent of the injury, and
cognitive and emotional factors of both patient
and clinician
PRINCIPLES OF MMT
Daniels and Worthingham describe P+ as the
grade indicating movement of the segment
through full range of motion in the gravity-
diminished or in the partial range against
gravity.
Kendall et al consider P+ (30%) as
movement of the extremity through a larger
arc of motion in the gravity-diminished
position than that designated by the criteria
for 20 percent grade.
PRINCIPLES OF MMT
In contrast, for the same muscle group, Kendall
et al, have the patient either sitting or supine,
moving the supinated forearm to a test position
of 90º flexion or less, or holding the test
position against the applied force. Stabilization
is minimal by the examiner who places one
hand under the patient’s elbow.
: (DANIEL & WORTHINGHAM GRADING SCALE
1995)
Rating muscle tests is a skill that takes a long time
to learn and perform with reliability. It is important
to learn how much resistance a “normal” muscle
can tolerate to know when a muscle is not
performing to its potential. All tests must be
performed bilaterally and the unaffected side
should be tested first. This is crucial because the
tester can then get an accurate idea of how much
resistance the unaffected side can tolerate and
what would be considered normal for the patient.
PRINCIPLES OF MMT
MMT requires attention to positioning,
stabilization and the methods of applying
external force to the body segment.
Standardization of these factors from one
patient to another is important because the
examiner must develop an experiential
model with which the results of each muscle
group tested will be compared.
PRINCIPLES OF MMT
There are differences between testing methods
in positioning , stabilization and the way in
which manual forces are applied.
Daniels and Worthingham 1980 recommended
elbow flexion test from sitting with arm
stabilized at the side, and if the biceps is the
main concern, the forearm supinated. The arm
should move through full arc of motion with the
examiner applying force at the end of motion
(break test).
PRINCIPLES OF MMT
In contrast for the same muscle group
Kendall et al 1971, have the patient either
sitting or supine, moving the supinated
forearm to a test position of 90ºof elbow
flexion or slightly less or holding the test
position against the applied force.
The examiner’s force is applied to the
forearm in the test position of 90º of elbow
flexion. Stabilization hand is under the
patient’s elbow.
PRINCIPLES OF MMT
Although the two methods are different
there is no evidence suggesting different
results.
Position (sitting and supine) can yield
different strength measures.
Muscle torque in example of Daniels and
Worthingham, the flexors are mechanically
and physiologically disadvantaged.
PRINCIPLES OF MMT
The effect of the external force in resisting
muscle group torque is a function of the
distance of its application from the joint axis.
If the examiner changes the distance at
different times with the same patient and
among patients, appropriate measurement can
not be obtained.
The skill of examiner to apply external force is
important (gradual, in correct direction and
differentiating).
PRINCIPLES OF MMT
The muscle ability to develop tension varies
according to the type of muscle contraction.
Eccentric contraction generates the greatest
amount of tension followed by isometric and
then concentric contraction.
PRINCIPLES OF MMT
The effect of the external force in resisting
muscle torque is a function of the distance of
its application from the joint axis.
If the examiner changes the distance at
different times with same patient or among
patients the muscle strength related to sex,
age, body type and life style cannot obtained.
RELIABILITY OF MMT
Intra-rater reliability examined by two
therapist performed MMT on poliomyelitis
patients at 6 week interval. Intra-examiner
agreement occurred on 65% and 54% of
the grades. Agreement occurred within a
plus or minus grade on 82% and 84% of
the muscle tested, Iddings and Smith
1961,
RELIABILITY OF MMT
Iddings and Smith 1961, had 10 physical
therapists complete a MMT on a poliomyelitis
patients within 2 week period. A training period
was not provided; each examiner performed the
test by his or her customary manner.
Nine of the examiner’s muscle grades were
compared with the tenth. The nine physical
therapist on the average agreed completely with
the tenth (45.3%) and 63.8% in plus or minus
grades.
RELIABILITY OF MMT
An inter-rater reliability study, physical
therapist, nurses and physicians were
instructed in standardized methods of
muscle testing. They reported that the
average difference between examiners was
7.1%. When two physical therapist were
compared, the difference in grading was
3%, in agreement in 60% of instances and
95% within plus or minus one grade.
VALIDITY OF MMT
MMT has face validity which is defined as the
extent to which the test appears to measure
what it was intended to measure.
Content validity reflects the adequacy of test
construction (known physiologic, anatomic, and
kinesiologic principles).
For example, test grade fair for tibialis anterior
the muscle should be able to move the foot
through full arc of motion against gravity.
VALIDITY OF MMT
The tibialis anterior should be able to resist
some degree of applied external force.
MMT has some content validity because it
measure directly the torque of muscle testes
but not all types of contractions or the rate of
tension develop during test.
Agreement of knowledgeable persons that test
construction is sound is an indication of a high
degree of content validity of a test.
VALIDITY OF MMT
Construct validity as related to MMT, represents
the degree to which one can generalize the
results of the test to relevant behaviors.
As in tibialis anterior example which indicates
the muscle inverts and dorsiflexes the foot
through full range of motion while subject is
sitting over edge of table (non-weight bearing)
while it is main muscle in gait (push off and
heel strike).
VALIDITY OF MMT
Because MMT do not examine muscles
during meaningful functional activity, the
use may be limited for the neurological
patients.
MMT is hypothesized as valuable
measurement tool for the clinical
assessment of patients with
neuromuscular problems.
MMT OF THE PEDIATRIC PATIENT
Muscle testing the pediatric patient is different
from the technique used in adult practice.
It is essential to have an understanding of
normal growth and development.
In very young child, the use of reflexes will
assist in the evaluation process.
In the older child, the use of developmental
tasks will help to assess muscle activity.
MMT OF THE PAEDIATRIC PATIENT
It is better to divide the exam into three age
and developmental categories:
1- infants: birth through 12 months.
2- toddler: 12 months through 24 months.
3- preschooler: 24 months through 48 months.
Children over 4 years of age can be more
formally tested.
MMT OF THE PEDIATRIC PATIENT
Early Reflexes
Disappearance Emergence Reflex
5 to 6 months birth Moro
3 months birth Palmar grasp
12 months birth Plantar grasp
12 months birth Placing
Persists 6 to 9 months Protective: lateral
Persists 9 months Protective: parachute
MMT OF THE PEDIATRIC PATIENT
Developmental Milestones
Activity Age
Flexion of limbs
Ventral suspension, head in line with body birth
Head control midline
Reaches for objects
Head upright in prone
3 months
Sits with balance from hands
Can bear weight on leg
Transfers objects hand to hand
6 months
Sits independently
Pulls to stand
Crawling and cruising
Pincer grasp
9 months
Walking alone 12 months
MMT OF THE PEDIATRIC PATIENT
Developmental Milestones
Activity Age
Creep up stairs
Throws a ball 18 months
Runs
Walks up and down steps
Kicks a ball
24 months
Jumps 30 months
Stands on one foot momentarily 36 months
Hops on one foot
Throws a ball overhand 48 months
skips 60 months
THE MUSCULOSKELETAL EXAM
The infant exam:
1- by observation.
2- evaluation:
From supine.
From prone.
Vertical.
Horizontal.
Sitting.
Floor play
THE MUSCULOSKELETAL EXAM
The toddler exam:
1- by observation.
2- by evaluation:
Sitting on the table or parent’s lap: evaluate
upper limb by using toy, transfer objects to the
opposite hand. Check lateral protective reflex.
Floor exam: watch child from supine to sit, stand
up and watch trunk and lower limbs, ask child to
walk, have child kick a ball.
THE MUSCULOSKELETAL EXAM
The preschool exam
1- observation.
2- evaluation:
Sitting on the exam table.
Lying on the exam table.
Floor exam.
6 MINUTE WALK TEST
This test measures your
response to exercise, at your
own pace. Some people have
no problems at all. Others may
have shortness of breath, chest
pains, leg pains, etc. You may
stop the test at any time if you
are not feeling up to it or if a
problem occurs during the
walk.
TANDEM WALK TEST
Description
The TW quantifies characteristics of gait as the
patient walks heel to toe from one end of the
forceplate to the other. Measured parameters
are step width, speed, and endpoint sway
velocity.
REACTION TIME
Reaction Time (RT) is the time in seconds
between the command to move and the
patient's first movement.
STANDING BALANCE TEST
the person stands on one leg for as long as
possible. Give the subject a minute to practice
their balancing before starting the test. The
timing stops when the elevated foot touches
the ground or the person hops or otherwise
loses their balance position. The best of three
attempts is recorded. Repeat the test on the
other leg.
