Strength and Range-of-Motion Examination
Skills for the Clinical Orthotist
Edward L. Barber, CO
ABSTRACT
Orthotists must be able to perform accurate evaluations of a patient's joint
range of motion and muscle volition to
provide successful outcomes to patient
management. Discussed are basic concepts related to the successful achievement of these evaluations. Because
physical therapists perform these evaluations daily as an integral part of their
therapy, references are made to their
texts and methods.
Introduction
As orthotists we are expected to evaluate a patient's range of motion (ROM)
and muscle strength to develop recommendation for treatment. More and
more we do this as part of a healthcare
team consisting of physician, physical
therapist and orthotist. The American
Board for Certification in Orthotics & Prosthetics Inc. (ABC) Role Delineation Study has identified the need for
orthotists to perform range-of-motion
and muscle strength evaluations as part
of their clinical assessment. The testing
of these skills comprises a significant
portion of the orthotic exam. That being said, we could benefit from a review of evaluation techniques.
Range of Motion
Proper evaluation of joint ROM and
muscle strength (volition) are essential
to successful patient management. Success in these evaluations is based on use
of accepted measuring methods. As orthotists we would benefit from observing our colleagues in physical therapy
who have extensive training in these
evaluations. They assess patient improvement based on increases in range
of joint motion and muscle strength.
For joint motion, the accepted method is that of the American Academy of
Orthopaedic Surgeons (AAOS) whose
handbook Joint Motion - Method and
Recording is excellent (1). AAOS's
method is based on six basic principles:
- Neutral Zero Method as described
by Caves and Roberts in 1936 (2).
- All motions of a joint are measured
from defined zero starting point positions. The degrees of motion of a joint
are added in the direction the joint
moves from the zero starting position.
- The extended "anatomical position" of an extremity is accepted as
zero degrees rather than as 180 degrees.
- Motions are described as active or
passive.
- Active motion is the patient's
movement of the joint through a specified arc of motion.
- Passive motion is the examiner's
movement of the joint through a special
fled arc of motion.
Both motions are compared to the accepted ROM for that joint, and any limitation in range due to muscle contracture; capsule restriction; or ligamentous.
bony or spastic antagonist is noted.
- A distinction is made between the
terms extension and hyperextension.
Extension is the natural motion opposite to flexion at the zero starting position. This is present in wrist and shoulder joints. If, however, the motion opposite to flexion at the zero starting
position is an unnatural one, such as
that of the elbows or knees, it is referred to as hyperextension.
- Limitation of joint motion is described simply. An example of a limitation of joint motion is an elbow that
can only be flexed from 30 degrees
(above 0 deb./neutral) to 90 degrees
(above 0 deb./neutral). Normal ROM
is 0 degrees to 150 degrees.
- The elbow flexes from 30 degrees to 90 degrees.
- The elbow has a flexion deformity of 30 degrees with further flexion to
90 degrees.
Limitations of joint motion can be
soft tissue or bony. In either case, these
limitations must be noted so that during testing the patient or examiner does
not try to move the joint past the limitation. Also, muscles are graded on the
ability to move the joint through the
entire ROM available, not the average
range.
To obtain the most accurate ROM,
two people should work together. One
person should range the joint while the
other places and reads the goniometer.
A goniometer that is easy to read and
holds its position while being read will
increase accuracy.
Experience has shown the most accurate ROMs are obtained if the joints
are ranged slowly and smoothly. Avoid
grasping the extremities too tightly.
Move elbow or knee joints into hyperextension slowly and with support.
Functional ROM Measurement
As orthotists, we must appreciate the
need to measure joint ROM in the
functional positions for which we will
be providing our orthoses.
In addition, problems can occur
when we try to perform ROM and muscle testing on joints affected by multi-joint muscles. For example, the ankle
and knee joints are crossed by the gastrocnemius. We must remove its affect
on the ankle by flexing the knee when
trying to range that joint, but we must
include its affect on the ankle by extending the knee when we develop our
orthotic management plan.
Muscle Strength
Many methods can be used to increase
muscle strength. The two most accepted methods in physical therapy training
programs are the Lovett Method and
the Aids to Investigation of Peripheral
Nerve Injuries (AIPNI) Method. An
excellent text on this subject is Muscles
Testing and Function by Kendell, Kendell and Wadsworth (3).
As orthotists we should focus on
functional muscle groups when we perform our evaluations-i.e., hamstrings
and quadriceps. We provide orthotic
management, i.e., knee flexion and
knee extension, because of the effects
of these groups.
Muscle Testing Considerations- Patient Positioning is crucial to accurate muscle testing. Muscle testing
considers the patient's ability to move
the tested joint through its range of
motion against gravity. For a patient
who cannot do this, the joint is placed
in a position where gravity does not
affect muscle test. The intelligent handling of affected joints and muscles is
more important than demanding the
patient be tested in a gravity-free position.
- Test Position, Test Movement. Test
position is the position in which the
part (and joint) is placed by the examiner. The patient is asked to hold that
position, if possible. By placing the patient's joint in the test position, the examiner is better able to detect any substitution for weak muscles because of a
shift in the position of either the proximal and/or distal part. Test movement
is a movement of the joint through a
specified arc of motion. This movement is called active range of motion.
Barring limitations in range, failure to
complete a full ROM can be interpreted as muscle weakness.
- Contracture, Shortness. A contracture causes an almost complete loss of
ROM of a joint. Shortness is the partial
loss of ROM.
- Joint Instability can have a marked
affect on muscle testing. A patient can
have a full contraction of a functional
muscle group at the hip, but due to a
dislocated hip, little or no movement is
achieved. Orthotically, we must protect the hip and manage it as if the
muscle group were as weak as demonstrated.
- Pressure is the force applied by the
examiner's hand to determine the
strength of the muscle holding the joint
in the test position. This force is directly opposite the line of pull of the muscle or tendon. In general, this pressure
is applied near the distal end of the
lever in which the muscle is inserted.
For patients who demonstrate muscle strength above grade 3 (fair), the
amount of pressure applied is the determining factor. At this grade the patient moves the part against gravity
into the test position. Consideration
must be made for the size of the patient
and the cross-sectional area of the
functional muscle group tested. The
pressure exerted against a child whose
wrist extensors are tested will be much
less than that against an adult whose
knee extensors are tested. However,
both could be graded 5 (normal).
Pressure must be applied gradually
in testing patients whose degree of
strength is above grade 3 (fair). The
patient must be able to "hold-on"
against the examiner's gradually applied pressure. Even slight pressure applied suddenly can break the pull of a
muscle with strength ranging from
grade 3+ (fair+) to 5 (normal).
- Substitution is when a muscle or
muscle group attempts to compensate
for a weak or paralyzed muscle. These
substitutions appear similar to normal
movements. The examiner must learn
to identify these substitutions by placing the part in the test position and by
using proper patient positioning as
much as possible. The former action
allows even inexperienced examiners
to detect the sudden shift of the body
part, which accompanies the substitution for muscle weakness. Placing the
patient in the proper position tends to
block known substitution patterns by
resisting body shifting and turning the
body part to use gravity.
- Anti-Gravity, Gravity-Lessened.
Gravity is a form of resistance affecting
the testing of trunk, neck and extremity muscles. Anti-gravity movements
are movements upward in the vertical
plane, while gravity-assisted movements are horizontal movements downward in the vertical plane. Movements
in the horizontal plane are gravity-lessened. All of grades 0 (zero) through
2+ (poor +) and part of grade 3- (fair-)
are performed in gravity-lessened positions. To reduce fatiguing the patient,
it is acceptable to perform an assistive
movement in the anti-gravity position,
when applicable, for grades 2 (poor)
and 2+ (poor+).
- Testing Children. A child's muscle
strength can be tested up to grade
(fair) without much difficulty. In higher grades, success depends on the
child's cooperation and understanding
Young children seldom cooperate in
strong test movements.
Clinical Relevance to the
Orthotist
We must perform our evaluations with
consideration of the orthotic management we intend to provide. For example, if we are to provide HKAFOs for a
child with Myelodysplasia, we must simultaneously evaluate the child's hips
for internal rotation, extension, adduction and range. Evaluating these characteristics individually might cause us
to miss an abduction contracture of one
of the hip joints. This mistake could
unwittingly lead to a created "pelvic
obliquity" if the hips were equally abducted as is usual with HKAFOs. The
side of the pelvis with the adducted hip
would have to rise into an oblique position to allow the thigh to be placed into
the thigh cuff. Not only would a pelvic
obliquity be created, but also an apparent limb-length inequality. Additionally, a scoliosis might be created or an
existing one increased.
- Plan Test Format: Standing, Sitting, Supine, Prone and Side-laying.
Use or develop an evaluation form that
matches the flow of your testing. It
should guide the examiner through the
planned examination and should be
clear enough to point out missing data.
- Orthotic Prescription Development. Plan fatigue into the orthotic recommendation. An increasing number
of patients with post-polio syndrome
can no longer function without orthoses and require increased orthotic
management. This population is quite
prone to fatigue. When evaluating
patients for orthoses, consider their
pre-evaluation level of fatigue as well
as their test-fatigue. Consider the
strength of patients' upper extremities
with respect to donning/doffing and
choice of closures for orthoses and/or
shoes where appropriate.
Although it is acceptable for a physical therapist to define a patient's ROM
as "within normal limits," it does little
for orthotists to use this terminology.
We are concerned with the actual
ranges of motion of a joint and whether
we are to lock, limit, resist or assist at
that joint. Therefore, we need to cite
degrees for our evaluations.
Edward L. Barber, CO, is facility manager at Atlanta Orthotics Inc. in Atlanta, GA
References:
- Joint motion-method and recording.
1965; American Academy of Orthopaedic
Surgeons, 430 N. Michigan Ave., Chicago.
Ill.
- Cave EF, Roberts SM. A method of
measuring and recording joint function. JB
JS; 1936; 18:2:455-466.
- Kendall HO, Kendall FP, Wadsworth
GE. Muscles testing and function. Williams
and Wilkins Co., 1971.
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