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Proprioceptive Neuromuscular Facilitation, Lecture notes of Medicine

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Proprioceptive
Neuromuscular
Facilitation
Techniques
in
Sports
Medicine:
A
Reassessment
Paul
R.
Surburg,
PhD,
RPT;
John
W.
Schrader,
HSD,
ATC
Objective:
The
purpose
of
this
survey
was
for
comparison
with
a
similar
1981
survey
to
determine
if
proprioceptive
neuromuscular
facilitation
(PNF)
techniques
are
being
imple-
mented
in
the
same
manner
today.
Design
and
Setting:
The
survey
was
made
available
at
the
1993
NATA
Clinical
Symposium.
Subjects:
The
subjects
were
131
athletic
trainers
represent-
ing
all
major
national
athletic
conferences
who
attended
the
1993
NATA
Clinical
Symposium
and
who
stated
that
they
used
PNF
exercise
in
their
practice.
Measurements:
The
survey
consisted
of
15
questions
deal-
ing
with
academic
preparation,
years
of
practice,
scope
and
method
of
preparation
in
PNF,
application
of
nine
PNF
tech-
niques
to
various
joints
and
regions
of
the
body,
and
the
most
successful
use
of
PNF
techniques.
Resufts:
PNF
techniques
are
most
frequently
applied
during
rehabilitation
of
the
knee,
shoulder,
and
hip,
similar
to
1981
H
ow
do
athletic
trainers
use
proprioceptive
neuromuscu-
lar
facilitation
(PNF)?
More
specifically,
what
PNF
techniques
have
athletic
trainers
found
to
be
effective
in
treating
injuries
in
specific
areas
of
the
body?
The
response
to
this
question
will
vary
in
context
and
scope.
Several
reasons
for
response
variability
will
be
briefly
examined
in
this
introductory
section.
In
accredited
athletic
training
programs,
undergraduate
athletic
training
students
are
exposed
to
PNF.
Students
are
expected
to
understand
the
underlying
principles
of
this
system
and
glean
concepts
related
to
application.
The
scope
of
coverage
is
predicated
upon
the
preparation
and
practical
experience
of
the
instructor
in
PNF.
Thus,
the
reply
to
the
question
regarding
application
of
PNF
techniques
may
be
brief
and
vague
for
some
athletic
trainers.
The
information
in
this
study
should
expand
knowledge
of
PNF
applications
and
possibly
provide
new
insights
for
effec-
tive
use
and
variations.
A
brief
review
of
the
literature
on
PNF
techniques
and
their
applications
is
provided
in
the
following
paragraph.
While
these
studies
provide
some
guidance
for
PNF
application,
one
must
be
aware
that
the
majority
of
these
studies
involve
subjects
with
no
type
of
athletic
injury.
By
contrast,
the
responses
of
athletic
trainers
in
this
study
relate
to
treating
injured
athletes.
Numerous
investigations
establish
PNF
techniques
as
more
efficacious
treatments
than
traditional
static
stretching
exer-
except
that
the
use
of
these
techniques
during
ankle
rehabili-
tation
has
increased.
In
both
studies,
the
most
frequently
used
techniques
were
contract-relax
and
hold-relax.
Two
techniques
not
surveyed
in
1981,
contract-relax-contract
and
hold-relax-
contract,
are
becoming
techniques
of
choice
for
elbow,
wrist,
hip,
and
knee
rehabilitation.
The
use
of
PNF
techniques
in
the
muscle
re-education
phase
of
rehabilitation
is
an
application
identified
in
this
survey
not
cited
by
athletic
trainers
in
the
1981
survey.
Conclusions:
Proprioceptive
and
kinesthetic
deficits
are
known
to
occur
after
certain
types
of
injuries,
and
the
use
of
PNF
techniques
to
correct
these
problems
is
a
natural
applica-
tion.
A
contemporary
trend
in
exercise
rehabilitation
is
multi-
planar
exercises,
which
are
typified
by
PNF
techniques.
Key
words:
proprioception,
neuromuscular,
facilitation,
inju-
ries
cises
for
range
of
motion
or
flexibility
enhancement.'-3
Treat-
ment
modalities
used
with
PNF
techniques
have
been
exam-
ined
to
ascertain
the
relative
merits
of
combination
treatments.
Results
of
studies
applying
cryotherapy
with
PNF
are
mixed
in
nature.45
Using
the
Hoffman
reflex
to
assess
motor
unit
recruitment,
results
show
that
PNF
techniques
produce
a
strong
but
brief
neuromuscular
inhibition.6
While
investigating
the
role
of
PNF
techniques
for
flexibility
development,
a
physical
therapist
reported
a
significant
increase
in
hamstring
flexibility
of
the
contralateral,
nonexercised
leg
with
the
contract-relax
technique.
This
transfer
effect
provides
additional
evidence
of
neurological
mechanisms
operating
with
PNF
applications.2
A
study
by
Hardy'
provides
insights
into
certain
applications
and
modifications
of
PNF
techniques.
He
examined
duration
of
isometric
contractions
and
found
6
seconds
to
be
the
ideal
length
of
contraction
time
for
the
hold-relax
technique.
An-
other
finding
is
that
this
hold-relax
procedure
may
be
more
effective
when
an
isotonic
contraction
of
the
hip
flexors
follows
the
isometric
contraction
of
the
hip
extensors.
This
modification,
called
hold-relax-contract,
was
incorporated
into
our
study.
There
is
a
paucity
of
data
about
the
application
of
PNF
for
injured
athletes
at
the
high
school
and
college
levels.
While
athletic
trainers
should
be
cognizant
of
data-based,
quasi-
experimental
studies,7-9
it
is
important
for
them
to
gain
insights
into
PNF
practices
implemented
by
their
peers,
thereby
adding
to
a
valuable
body
of
knowledge
in
the
area
of
rehabilitation.
In
essence,
this
survey
represents
the
"best
practice"
in
over
131
case
studies.
34
Volume
32
*
Number
1
*
March
1997
Paul
R.
Surburg
is
a
professor
and
John
W.
Schrader
is
coordinator
of
the
athletic
training
program
in
the
Department
of
Kinesiology,
Indiana
University,
Bloomington,
IN
47405.
pf3
pf4
pf5

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Proprioceptive Neuromuscular Facilitation

Techniques in Sports Medicine: A

Reassessment

Paul R. Surburg, PhD, RPT; John W. Schrader, HSD, ATC

Objective: The purpose of this survey was for comparison with a similar 1981 survey to determine if proprioceptive neuromuscular facilitation (PNF) techniques are being imple- mented in the same manner today. Design and^ Setting: The^ survey was^ made^ available^ at^ the 1993 NATA^ Clinical Symposium. Subjects: The subjects were 131 athletic trainers represent- ing all^ major national athletic^ conferences^ who^ attended the 1993 NATA^ Clinical Symposium^ and^ who stated that^ they used PNF exercise in their practice. Measurements: The (^) survey consisted of 15 questions deal- ing with^ academic^ preparation,^ years^ of^ practice,^ scope^ and method of preparation in PNF, application of nine PNF tech- niques to various joints and regions of the body, and the most successful use of PNF techniques. Resufts: PNF techniques are most frequently applied during rehabilitation of the knee, shoulder, and hip, similar to 1981

H ow do athletic trainers use proprioceptive neuromuscu- lar facilitation (PNF)? More specifically, what^ PNF techniques have athletic trainers found^ to^ be^ effective in treating injuries in specific areas of the^ body? The^ response to this question will vary in^ context and^ scope. Several reasons for response variability will be^ briefly examined in this introductory section. In accredited^ athletic training programs, undergraduate athletic^ training students^ are exposed to^ PNF.^ Students^ are^ expected to^ understand the underlying principles of this^ system and^ glean concepts related to (^) application. The scope of coverage is predicated upon the preparation and practical experience of the instructor in PNF. Thus, the reply to the question regarding application of PNF techniques may be brief and vague for some athletic trainers. The information in this study should expand knowledge of PNF applications and possibly provide new insights for effec- tive use and variations. A brief review of the literature on PNF techniques and their applications is^ provided in the^ following paragraph. While these studies (^) provide some (^) guidance for PNF application, one must be aware that the majority of these studies involve subjects with no type of athletic injury. By contrast, the responses of athletic trainers in this study relate to treating injured athletes. Numerous investigations establish PNF techniques as more efficacious treatments than traditional static stretching exer-

except that the use of these techniques during ankle rehabili- tation has increased. In both studies, the most frequently used techniques were contract-relax and hold-relax. Two techniques not surveyed in 1981, contract-relax-contract and hold-relax- contract, are becoming techniques of choice for elbow, wrist, hip, and knee rehabilitation. The use of PNF techniques in the muscle re-education phase of rehabilitation is an application identified in this survey not cited by athletic trainers in the 1981 survey. Conclusions: Proprioceptive and kinesthetic deficits are known to occur after certain types of injuries, and the use of PNF techniques to correct these problems is a natural applica- tion. A contemporary trend in exercise rehabilitation is multi- planar exercises, which are typified by PNF techniques. Key words: proprioception, neuromuscular, facilitation, inju- ries

cises for range of motion or flexibility enhancement.'-3 Treat- ment modalities used with PNF^ techniques have^ been^ exam- ined to ascertain the relative merits of combination treatments. Results of studies applying cryotherapy with^ PNF^ are^ mixed^ in nature.45 Using the Hoffman reflex to assess motor unit recruitment, results show that^ PNF^ techniques produce a^ strong but brief neuromuscular inhibition.6 While investigating the role of PNF techniques for flexibility development, a physical therapist reported a significant increase in hamstring flexibility of the contralateral, nonexercised leg with the contract-relax technique. This transfer effect provides additional evidence of neurological mechanisms operating with PNF applications.2 A

study by Hardy' provides insights into certain^ applications and

modifications of PNF techniques. He examined duration of isometric contractions and found 6 seconds to be the ideal length of contraction time for the hold-relax technique. An- other finding is that this hold-relax procedure may be more effective when an isotonic contraction of the hip flexors follows the isometric contraction of the hip extensors. This modification, called hold-relax-contract, was incorporated into our study. There is a (^) paucity of (^) data about the application of PNF for injured athletes at the high school and college levels. While athletic trainers should be cognizant of data-based, quasi-

experimental studies,7-9^ it^ is^ important^ for^ them^ to^ gain

insights into PNF practices implemented by their peers, thereby adding to a valuable body of knowledge in the area of rehabilitation. In essence, this survey represents the "best practice" in^ over^131 case^ studies.

34 Volume 32 *^ Number 1 * March 1997

Paul R. (^) Surburg is a professor and John W. Schrader is coordinator of the athletic training program in the Department of Kinesiology, Indiana University, Bloomington, IN 47405.

Over a 13-year period, aspects of therapeutic exercise or protocols have changed in emphasis, role, and (^) importance. Isokinetic exercises were the exercise of choice 13 years ago for various aspects of the rehabilitation process and considered "cutting edge" protocols. While isokinetic exercises are still important in rehabilitation, closed kinetic chain exercises are considered vital in many contemporary therapeutic protocols. Along with changes in priority and usage among types of exercises, there may also be application changes within a therapeutic regimen. Are certain PNF techniques being used more frequently or differently in contemporary rehabilitation programs than in 1981? The purpose of this study was to

compare this survey with a 1981 studyl to determine if PNF

techniques are being implemented in the same manner as 13 years ago.

METHODS One hundred and thirty-one athletic trainers participated in this study and represented all major athletic conferences in the United States. The survey instrument was made available at the 1993 National Athletic Trainers' Clinical Symposium. Survey instruments were (^) available on (^) a table in the registration area. Potentially all registered athletic trainers, approximately 8,000, could have (^) participated. Participants were (^) asked to complete this survey only if they used some type of PNF exercise. As with the 1981 study, athletic trainers were selected because they either inaugurate and supervise the use of PNF techniques or administer these exercises based upon a physician's recom- mendation. The foundation of this therapeutic system is predicated upon the involvement of four neurophysiological mechanisms: re- flexes, resistance, irradiation, and successive induction. Irradi- ation is the "spread of excitation in the central nervous system which causes contraction of synergistic muscles in a specific pattern."1' Successive induction refers to contraction of an agonist muscle group followed by activation of the antagonist muscle group. A key component in PNF is the execution of movement in diagonal, spiral patterns. 12-14^ Some of the PNF techniques discussed in succeeding paragraphs are executed in the cardinal planes rather than diagonal, spiral patterns. These modifica- tions of PNF techniques will be designated as Facilitation Patterns. Diagonal patterns accompanied by resistance are intended to elicit irradiation and muscle recruitment. Detailed explanations of PNF may be found in various publica- tions. 13- Nine different PNF techniques were surveyed in this study. Seven were included in the 1981 study and were based upon the work of Kabat' 1 and Knott and Voss12: (^) repeated- contraction, (^) rhythmic-initiation, slow-reversal, slow-reversal- hold, rhythmic-stabilization, contract-relax, and hold-relax. Two additional techniques included in this study, contract- relax-contract and hold-relax-contract, were based upon the work of Hardy' and represent modifications of hold-relax and contract-relax (^) techniques. Respondents identified use of these techniques for^ the^ following joints: neck, shoulder, elbow/ wrist, fingers, back, hip, knee, and ankle.

As with the 1981 study, an open-ended question was included in the survey. Athletic trainers were asked to describe their most successful use of PNF techniques. Ninety-two (70%) individuals provided additional insights into PNF or Facilitation Patterns use through this question. The frequency and nature of the responses in this portion of the survey were similar to and seem to validate the responses of the multiple choice portion of this instrument. While frequency of use for the nine techniques is not synonymous with technique efficacy, it would seem evident that the pragmatic athletic trainer would discontinue application unless satisfactory results are obtained. The instrument consisted of 15 questions. Questions 1 through 4 dealt with academic preparation, years of practice, and scope and method of preparation in PNF. The next 7 questions dealt with the application of the nine PNF techniques to various joints and regions of the body. Following the open-ended question, all nine PNF techniques were succinctly described. The first few sentences in each succeeding para- graph are a paraphrase of the technique description.

Repeated-Contraction

This technique involves executing diagonal, spiral-patterned movements against resistance several times through a full range of motion. The athletic trainer selects the diagonal pattern that will enhance the strength or movement of a targeted muscle or muscle group. A vital element in PNF is the diagonal spiral pattern, which serves as a basis of movement for the various techniques. These diagonal patterns with a rotary component involve movements in three dimensions with sequential, and at times, simultaneous movement at several joints. Motions are initiated distally and proceed proximally. Patterns are named according to their finished position. For each direction there are two basic patterns (Fig 1). For the shoulder the motions are flexion-adduction-external rotation, also referred to as Dl, and flexion-abduction-external rotation, also referred to as D2. Reciprocal or antagonist patterns are implemented with certain PNF techniques. Extension- abduction-internal rotation and extension-adduction-internal rotation are the reciprocal shoulder patterns. One could substi- tute hip for shoulder and repeat the pattern sequences for DI and for (^) D2; the rotation motion would change from external to internal (^) rotation or vice versa for the D2 sequences.

EXTENSION r d' EXTENSION Fig 1.^ The^ PNF^ techniqu of^ repeated contraction involves execut- ing diagonal, spiral-pattemed movements against resistance sev- eral times through a full range of motion. Shown here are the two basic patterns for the shoulder and hip.

Joumal of Athletic Training 35

40

P E R C E N T 0 T 0 T A L S A M L E

30

120 .g

NECKSHOULDER ELBOW/FINGERS WRIST BACK HIP KNEE ANKLE

Fig 2. PNF^ techniques were used most frequently for injuries to the knee, shoulder, hip, ankle, elbow/wrist, and neck.

Neck and Upper Extremity Usage

Figure 3 shows the usage of the nine techniques for neck and upper extremity treatments. (^) Contract-relax, the (^) technique used most frequently with the neck, involves passive motion in one direction followed by resisted motion in the (^) antagonistic pattern. Slow-reversal^ was^ opted as^ the^ second most frequently used (^) technique. An area of (^) commonality among these proce- dures is neck motion in one (^) direction followed by movement in the opposite direction. Slow-reversal, however, initially in- volves movement (^) by the antagonistic muscle groups, and contract-relax is begun with passive motion of the agonist muscles. A finding of this study was the decline in use of rhythmic stabilization for neck conditions. The three most frequently applied techniques for shoulder rehabilitation are contract-relax, repeated-contraction, and hold-relax. Use of the latter two techniques has reversed since

  1. Repeated contractions are cited as rehabilitation protocol for "throwing shoulder and shoulder strains." One respondent elaborates upon the implementation of repeated contractions, and emphasizes the use of spiral pattems along with rotation, flexion/extension, and abduction/adduction.

60: NECK (^) :SHOULDER LIIELBOW/WRIST

PE (^) 40~ 3 0 _

1'

REPEAT. RHYTH. SLOW SLOW RHYTH. (^) CONT. CONT. HOLD HOLD CONT. INIT. REV. REV.H. STAB. RELAX REL.C. RELAX REL.C.

Fig 3. Contract-relax and slow reversal were the PNF techniques used most frequently for injuries to the neck, while contract-relax, repeated contraction, and hold-relax were used most often for injuries to the shoulder.

For the elbow/wrist areas, contract-relax, hold-relax, and contract-relax-contract were the three most (^) frequently used techniques. In the 1981 study repeated-contraction was the second most frequently applied technique.

Back and Lower Extremity Injuries

As with the 1981 study, contract-relax and hold-relax were the techniques of choice for the hip region. In the open-ended question these techniques are often cited as successful rehabil- itation procedures for hamstring problems. The sequencing of hold-relax followed by contract-relax was noted by several persons. As one peruses Figure 4, one sees that the hip designation could cover injuries to abductors, adductors, and the quadriceps. Technique use at the knee parallels usage at the hip. The biarticular nature of certain muscle groups would again ac- count for some of this duplication of the two most frequently selected techniques. Rhythmic-stabilization is not selected very frequently by respondents but is mentioned by several athletic trainers in the open-ended question. While the specificity of the injury was not delineated, motionless exercises have been suggested in managing chondromalacia patella. Hold-relax- contract was selected by one person to treat patella tendinitis. This technique and contract-relax-contract were being exten- sively used for hip and knee problems. Inspection of Figure 4 reveals that, as one descends the joints of the lower extremity, repeated-contraction becomes more frequently applied in rehabilitation situations. This same observation may be applied to (^) rhythmic-initiation. Several participants cited the latter^ technique as^ the^ one^ found^ to provide the most success in treating ankle (^) injuries. One athletic

trainer stated,"[For] lateral ankle sprain I like to use slow

reversal to maintain and (^) gain strength." While not for exclusive use at the (^) ankle, another trainer (^) commented, "I have had success (^) using PNF (^) patterns in (^) the swimming pool for both upper extremity and lower^ extremity muscular problems." Again, a^ more^ generic application was provided by another respondent: "The^ type I^ use^ most depends: for a very acute or

60

p E R C E N T (^0) F S A MP L E

_ BACK HIP KNEE EMU ANKLE 50

40

30 -

20

REPEAT. RHYTH.SLOW SLOW RHYTH. CONT. CONT. HOLD HOLD CONT. INIT. REV. REV.H. STAB. RELAX REL.C. RELAX REL.C. TECHNIQUE Fig 4. For injuries to the back and lower extremities, the use of repeated contraction and rhythmic initiation increased.

Journal of Athletic Training 37

painful athletic injury I will use hold-relax. For stretching I use contract-relax or slow-reversal and for re-education I^ use repeated-contraction."

DISCUSSION A comparison of PNF use for various joints of the body revealed similar trends between this study and the 1981 publication. In both studies knee, hip, and shoulder joints were the most frequently treated with PNF techniques. The most radical departure in usage between the two studies is the ankle, which in our study replaces the neck among the top four joints. In the 1981 study, rhythmic stabilization was implemented more extensively than slow-reversal and con- tract-relax. Rhythmic stabilization has been recommended as a mobilizing technique,'7'18 and as a means to gain relaxation, increase strength,'5 and enhance circulation.'2 An athletic trainer notes, for throwing injuries, the use of repeated con- tractions with flexion/extension, abduction/adduction, and ro- tation incorporated into spiral patterns. A study by Blakely and Palmer'9 found with flexion, adduction, and external rotation pattern of the shoulder, lateral or external rotation occurred during the first phase of this pattern and medial rotation was evident during the last phase of this spiral pattern. This finding should be considered when selecting patterns for^ shoulder rehabilitation. Contract-relax, hold-relax, and contract-relax-contract were the three most frequently used techniques for the elbow/wrist areas. The second most frequently applied technique in the 1981 study was repeated-contraction. Contract-relax-contract technique was^ not^ included^ in that^ survey. While^ repeated- contraction and this (^) technique are both isotonic in nature, contract-relax-contract involves motion of both (^) antagonistic and (^) agonistic muscle (^) groups. This (^) reciprocity of motion (^) may enhance the rehabilitation process for these joints, because successive induction is a basic tenet of PNF. For lower extremity rehabilitation, two techniques (contract- relax-contract and hold-relax-contract) are being applied more frequently than four of the original techniques." While these two techniques were not included in the 1981 instrument, the open-ended part of the 1981 survey did not elicit responses about utilizing these techniques. In a relatively short period of time these techniques are becoming standard protocols for certain treatment situations. In (^) 1981, PNF exercises were (^) being used as (^) warm-up procedures. While this may continue to be the case, no one mentioned this usage in the present survey. A role for PNF in the re-education phase of rehabilitation was identified by certain athletic trainers. There is documen- tation that with (^) certain types of athletic injuries proprioception and kinesthesis are adversely affected. A loss of kinesthetic sense after glenohumeral dislocations is identified in a study, and the use of PNF exercises to remediate this deficit is recommended.20 Two researchers emphasize the need to de- velop proprioception, kinesthesia, and neuromuscular control for shoulder complex rehabilitation.2' They suggest a type of plyometric training utilizing D2 movements. Additional clini- cal and (^) laboratory investigations are needed to ascertain how

the standard PNF techniques and elements of the therapeutic approach devised by these investigators may be used to enhance kinesthesia and neuromuscular control. In like manner, additional investigations are needed to determine the optimal duration of isometrics contraction (hold) incorporated into PNF techniques. At the present time there is not a clear trend regarding this issue. Hardy's' work indicates 6 seconds as an effective duration, but Nelson and Cornelius found no significant differences among 3-, 6-, or 10-second isometric contractions. Two issues must be addressed when comparing these studies. First, different PNF techniques were used in these studies. Duration of the isometric contraction may be related to the type of PNF technique. Second, while Hardy found 6 seconds to be statistically significant, Nelson and Cornelius did not find any significant differences. One must be cautious about trying to prove a point by retaining the null hypothesis. In the present survey, no input was received about optimal duration of isometric contraction associated with the hold aspect of a technique. Four of the surveyed techniques did involve an isometric contraction in^ some^ aspect of^ the technique. Respondents in certain^ cases^ did^ designate a^ type of athlete for whom^ a^ PNF^ technique was^ most^ effective.^ Repeated- contraction was cited as (^) being effective for the (^) throwing type of shoulder. Work done (^) by a (^) group of researchers8 indicates that different (^) types of athletes (^) (in their (^) study endurance athletes and (^) high-intensity athletes like (^) volleyball players and (^) sprinters) respond differently to contract-relax and a technique called agonist contract-relax. The possible interaction between a specific PNF technique and a certain type of athlete is a situation that the athletic trainer in the field should be cogni- zant of and is a possible line of inquiry for the researcher.

CONCLUSION

Proprioceptive neuromuscular facilitation^ techniques incor- porate movement in the three^ planes of the^ body. With the current emphasis on^ multi-planar exercises in^ treating athletic injuries, PNF procedures provide an effective means for delivering this^ type of^ approach. Specific techniques for treating various injuries and areas of the body are provided in this (^) study by athletic trainers who have (^) successfully applied them to injured persons. Rehabilitation of injuries has transcended strictly strength and range-of-motion development. While increments in these areas are important, neurological and neuromuscular enhancement are vital in contemporary rehabilitation protocols. Proprioceptive and kinesthetic deficits do accompany many types of injury. Data from this (^) study indicate that (^) athletic trainers are using PNF techniques in the re-education phase of injury treatnent.

REFERENCES

  1. Hardy L. Improving active range of hip flexion. Res Q Exerc Sport. 1985;56:1 11-
  2. Markos PD. Ipsilateral and contralateral effects of propnrioceptive neuro- muscular facilitation (^) techniques on (^) hip motion (^) and electromyographic activity. Phys Ther. 1979;59:1366-1373.
38 Volume 32 * Number 1 * March 1997