Getting Range of Motions Correct

18 March 2013 / How To, Impairment Physical Exam, Uncategorized / Comments Off on Getting Range of Motions Correct

The AMA Guides use Range of Motion rating to calculate impairment in joints
which move. For example, shoulders, knees, wrists, elbows.

There are a few simple steps to ensure that a Range of Motion rating is
correct. Sadly, many doctors are not familiar with these 5 simple steps.

The steps are based on the fundamental principle in the Guides that
measurements should be reproducible because we are measuring permanent
impairment. This means that the measurements should be CONSISTENT between
examiners and also when done by one examiner on several occasions. Why?
Because the impairment is PERMANENT and should not change.

Let me give you an example. If half of your arm were cut off, would the
length cut off change from examination to examination? No, because the
finding is permanent. Each doctor who measured your amputated arm should
get the same result.

Joints (like the shoulders, elbows, knees) with permanent impairment are
the same way. They should produce the same measurements each time a doctor
examiners them, if the doctor does the examination correctly.

So, here are the 5 simple steps to ensure that a Range of Motion rating of
a joint is correct:

1. The doctor should use a goniometer to measure the angles of motion of
the joint. A goiniometer is like a giant protractor (which you had in
junior high school) which measures angles. The doctor should use this
device to get an exact measurement of the angle of motion (for example,
flexion or extension in the shoulder). In the shoulder, the reference that
a goniometer should be used is found at p. 475-478 of the Guides where the
instructions for rating are given. The instructions tell the physician to
record the actual goniometer readings. (I can always tell when a doctor
has not used a goniometer because all of the measurements end in 0, for
example, 40 degrees, 50 degrees, 60 degrees--this means, usually, that the
physician is simply eye balling it and not using a goniometer.)

2. The physician should measure active motion of the joint. That means
the patient moves the joint under his own power. (See pp. 475-478 for the

3. The physician should do the measurements a minimum of 2 times in the
upper extremities (p. 20 of the Guides) and a minimum of 3 times in the
lower extremities (p. 533, Section 17.2f Range of Motion in the Lower
Extremities). Yes, these numbers are inconsistent. That is because the
physicians writing the principles of the Guides and the physicians writing
the lower extremity chapter did not talk to each other. The physician is
to record the actual measurements (see p. 475-479). That means they have
to be written down in the medical report or in the physician's notes (which
he must keep).

But here is what is most important. Why do we have the patient do at least
two motions and measure them? To ensure that the measurements are
reliable, consistent, and reproducible. That means that they are
permanent, do not change, and show up from one evaluation to another. This
principle is stated at p. 20 of the Guides:

"As with any biological measurements, some variability and normal
fluctuations are inherent in permanent impairment
ratings. Two measurements made by the same examiner using the Guides
that involve an individual or an individual's
functions would be consistent if they fall within 10% of each other.
Measurements should also be consistent between two
trained observers or by one observer on two separate occasions,
assuming the individual's condition is stable. "

So, a minimum of two measurements must be done in the upper extremities,
and three measurements in the lower extremities. The measurements must
fall within 10% of each other to be reliable.

Why is this? Because people with PERMANENT impairment can only move the
joint to the same position each time. By ensuring that a minimum of 2
measurements are done which fall within 10% of each other, we weed out
results which are not permanent.

Example: A patient demonstrates flexion in the right shoulder of 180
degrees and 0 degrees. Is this consistent? No. What does it tell us?
That the measurements are not reliable.

When a patient's measurements are not reliable, they cannot be used as a
basis for impairment rating. The resulting rating for that motion is 0%
WPI. (P. 20.)

4. The motions done (all of them) must fall within 10% of each other to be
deemed reliable. (p. 20)

5. Finally, if the right shoulder is injured, then the left uninjured
shoulder should also be measured. If that shoulder demonstrates impairment
(and has never been injured before), then that impairment is subtracted out
from the impaired shoulder per p. 453 of the Guides. The Guides use fancy
medical terminology for this: "If a contralateral 'normal' joint has a
less than average mobility, the impairment value(s) corresponding to the
uninvolved joint can serve as a baseline and are subtracted from the
calculated impairment for the involved joint. The rationale for this
decision should be explained in the report."

Essentially, the Guides use the uninjured joint as a baseline against which
to measure the injured joint.

So, in summary, for a perfect Range of Motion rating in a joint:

a. Find the joint you are dealing with.

b. Go to the section of the Guides where range of motion of that joint is
discussed. The section will tell you what motions need to be measured
(for example, flexion in the shoulder).

c. Use a goniometer to do the measurements. (p. 475-479 for the shoulder)

d. Have the patient do active motion of the joint (that means he moves the
joint under his own power). Measure the motion 2 times in the upper
extremities and 3 times in the lower extremities. (pp. 475 and 20 for the

e. Make sure the measurements fall within 10% of each other. If they do,
then you can use them for calculating impairment. If they do not, then
they cannot be used for calculating impairment for that motion, and the
corresponding rating is 0% WPI for that motion. (p. 20)

f. Measure any impairment in the uninvolved joint and subtract it from the
impairment in the involved joint. (p. 453)

g. Convert your final impairment to whole person impairment using the
conversion charts at p. 439 for the upper extremity and p. 525 for the
lower extremities.

And with that, you will have a perfect Joint Range of Motion rating every

Phil Walker, Esq.
Legal Director Impairment Rating Specialist

Phil Walker
Phil Neal Walker Law Corporation
"Workers' Compensation for the World"
250 King Street, Suite 414
San Francisco, California 94107
phone me at either:
+1 415.295.4447
cell: +1 415.816.3527
fax: 888.563.9444

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