Exercise Prescription and Patellofemoral Pain 73 … · focused on VMO with lateral patel-group 3, 16 ± strengthening 2.6 y ... referred to as the Muncie method, a modification of

72

Exercise Prescription and Patellofemoral Pain 73

The authors are with the rehabilitation sciences doctoral program and Division of Physical Therapy, University of Kentucky, Lexington, KY 40536.

Exercise Prescription and Patellofemoral Pain: Evidence for Rehabilitation

Lori Bolgla and Terry Malone

Objective: To provide evidence regarding the therapeutic effects of exercise on subjects with patellofemoral-pain syndrome (PFPS). Data Sources: Evidence was compiled with data located using the Medline, CINAHL, and SPORTDiscus data-bases from 1985 to 2004 using the key words patellofemoral pain syndrome, exer-cise, rehabilitation, and strength. Study Selection: The literature review examined intervention studies evaluating the effectiveness of exercise in subjects specifi-cally diagnosed with PFPS. Articles were selected based on clinical relevance to PFPS rehabilitation that required an intervention of a minimum of 4 weeks. Data Synthesis: The review supports using exercise as the primary treatment for PFPS. Conclusions: Evidence exists regarding the use of isometric, isotonic, isokinetic, and closed kinetic chain exercise. Although clinicians have advocated the use of biofeedback and patella taping, there is limited evidence regarding the efficacy of these interventions on subjects diagnosed with PFPS. Key Words: anterior knee pain, quadriceps, intervention, strength

Bolgla L, Malone T. Exercise prescription and patellofemoral pain: evidence for rehabilitation. J Sport Rehabil. 2005;14:72-88. © 2005 Human Kinetics Publishers, Inc.

Patellofemoral-pain syndrome (PFPS) is a common problem experienced by active adults and adolescents. Most often, patient complaints are of dif-fuse peripatellar and retropatellar pain, limiting the patient’s activities of daily living that require loading on a flexed knee. Such activities include ascending and descending stairs, squatting, and sitting for prolonged periods of time.1-3

Most patients with PFPS respond favorably to conservative interven-tion,3-5 and researchers have supported the use of quadriceps strengthening as a key component of the rehabilitation program.1,6-8 Natri et al9 conducted a 7-year prospective study and reported that restoration of adequate quad-riceps strength and function is necessary for recovery. Therefore, health-care practitioners should develop and implement a rehabilitation program that promotes normal quadriceps strength and function.

Many researchers have investigated the efficacy of various exercises in promoting quadriceps activity using surface electromyography (EMG).10-15

Research Reviews

72

Exercise Prescription and Patellofemoral Pain 73

The premise of these studies has been that exercises resulting in higher quadriceps EMG activity would benefit patients diagnosed with PFPS. These studies included normal subjects with no history of PFPS, which brings into question the effectiveness of these exercises for the treatment of PFPS. Undoubtedly, researchers should examine the effect of these exercises on subjects with PFPS.

The concept of evidence-based practice means that providing high-quality care depends on the ability to prescribe an intervention confirmed by scientific data.16 Clinicians must understand the “whys” of exercise prescription and the scientific rationale for making specific decisions.17 The purpose of this literature review is to provide a scientific basis for the therapeutic effects of exercise on subjects with PFPS.

Inclusion CriteriaAs mentioned previously, many studies have determined quadriceps activa-tion during a single exercise session using asymptomatic subjects; however, a limited number of studies have examined the effect of exercise on reducing symptoms associated with PFPS. Based on this limited evidence, we chose to include studies using subjects who were diagnosed with PFPS and partici-pated in an exercise-based intervention for a minimum period of 4 weeks. Based on this criterion, using the MEDLINE, CINAHL, and SPORTDiscus databases from 1985 to 2004, we found 16 acceptable articles.

Evaluation of EvidenceRather than using the meta-analysis process of evidence classification, we used a relevance-to-clinical-practice process for evidence or article selection. Patients with PFPS are often provided rehabilitation programs through outpatient interventions. These often are visit-based, with 12 visits over 4 weeks or some permutation of this sequence. Thus, for the selection process, included articles were required to emulate the normal practice of treatment lasting a minimum of 4 weeks. We used the last 20 years of literature as representative of contemporary practice. Table 1 provides a synopsis of each article, including the requisites for article inclusion (sample, subjects, dura-tion, intervention, calculated effect size, and implication for practice).

Open Kinetic Chain Exercise

Isometric Quadriceps Exercise

Pain-free quadriceps exercise is a key component of successfully treating patients with PFPS.7 Researchers think that isometric quadriceps exercises,

74 Bolgla and Malone Exercise Prescription and Patellofemoral Pain 75

Tabl

e 1

Su

mm

ary

of I

nter

vent

ion

Stud

ies

Incl

uded

in t

he R

evie

w o

f the

Lit

erat

ure*

Stud

y,

Effe

ct s

ize

type

Sa

mpl

e Pa

rtic

ipan

ts

Dur

atio

n In

terv

enti

on

for

pain

† Im

plic

atio

n

Ala

ca,18

N

= 2

2 M

ean

age:

D

urat

ion:

6 w

k A

ll su

bjec

ts

Pret

reat

men

t vs

Is

okin

etic

exe

r-Q

E A

ttriti

on: n

one

27 ±

6 y

Fo

llow

-up:

non

e pe

rfor

med

the

post

trea

tmen

t:

cise

can

impr

ove

Sym

ptom

s:

sa

me

isok

inet

ic

1.37

ex

tens

or-

24 ±

11

d

stre

ngth

enin

g

m

echa

nism

prot

ocol

.

stre

ngth

.C

lark

,19

N =

81

Age

ran

ge:

Dur

atio

n: 3

mo

Gro

up 1

: exe

rcis

e,

Gro

up: 1

vs

2,

Exer

cise

mos

t R

CT

Attr

ition

: 16

–40

y Fo

llow

-up:

1 y

ta

pe, a

nd e

xerc

ise

.06;

2 v

s 3,

.73;

be

nefic

ial i

n

10 a

t 3 m

o,

Sym

ptom

s:

G

roup

2: e

xerc

ise

1

vs 3

, .77

re

duci

ng p

ain,

32 a

t 1 y

>

3 m

o

and

educ

atio

n

tape

hav

ing

no

G

roup

3: t

ape

and

sign

ifica

nt e

ffect

.

ed

ucat

ion

Gro

up 4

: edu

catio

n C

ross

ley,

20

N =

71

Age

ran

ge:

Dur

atio

n: 6

wk

Gro

up 1

: McC

onne

ll-

Mea

n di

ffere

nces

Ph

ysic

al th

erap

yR

CT

Attr

ition

: 4

12–4

0 y

Follo

w-u

p: n

one

base

d pr

ogra

m

betw

een

grou

ps:

inte

rven

tion

is

Sym

ptom

s:

G

roup

2: “

sham

” .7

5 ef

ficac

ious

in

1–

144

mo

pr

ogra

m

re

duci

ng P

FPS

sy

mpt

oms.

Dou

cette

,1

N =

56

(kne

es)

Mea

n ag

e:

Dur

atio

n: 1

1 ph

ysi-

Su

bjec

ts p

artic

ipat

ed

Gro

up d

iffer

- Th

erap

eutic

exe

r-Q

E A

ttriti

on: n

one

grou

p 1,

22.

9

cal t

hera

py v

isits

in

an

indi

vidu

aliz

ed,

ence

s in

pai

n at

ci

se c

an b

e ef

fec-

± 1

1.2

y;

over

8 w

k co

mpr

ehen

sive

,

post

test

ing:

1.2

2 tiv

e in

dec

reas

ing

grou

p 2,

21.

8

Follo

w-u

p: n

one

5-st

age

inte

rven

tion

pa

in a

ssoc

iate

d

±

9.7

y;

fo

cuse

d on

VM

O

w

ith la

tera

l pat

el-

grou

p 3,

16

±

st

reng

then

ing

la

r co

mpr

essi

on

2.

6 y

sy

ndro

me.

Sym

ptom

s:

≥6

wk


Dur

sun,

21

N =

60

Age

ran

ge:

Dur

atio

n:

Gro

up 1

, bio

feed

back

N

/A: n

o si

gnifi

-

Bio

feed

back

did

R

CT

Attr

ition

: non

e 17

–50

y 5 ×

wk ×

4 w

k;

and

exer

cise

; gro

up 2

, ca

nt d

iffer

ence

s

not r

esul

t in

mor

e

D

urat

ion:

>an

3

days

wk ×

2 m

o ex

erci

se o

nly

in V

AS

at p

ost-

de

crea

ses

in p

ain

aver

age

of

Follo

w-u

p: n

one

te

stin

g (P

= .1

4)

than

exe

rcis

e

10

.8 ±

7.7

mo

al

one.

Ebur

ne,22

N

= 7

5 A

ge r

ange

: D

urat

ion:

mon

thly

G

roup

1, i

som

etri

c In

suffi

cien

t B

oth

prog

ram

sR

CC

A

ttriti

on: 2

5 10

–35

y un

til p

ain-

free

ex

erci

se; g

roup

2,

info

rmat

ion

to

bene

fited

all

Dur

atio

n: N

/A

or fo

r 3

mo

McC

onne

ll re

gim

en

calc

ulat

e pa

rtic

ipan

ts.

Fo

llow

-up:

non

eG

affn

ey,23

N

= 7

2 A

ge r

ange

: D

urat

ion:

dai

ly P

T G

roup

1, O

KC

In

suffi

cien

t B

oth

form

s of

exe

r-R

CT

Attr

ition

: 12

11

–65

y an

d su

perv

ised

ex

erci

se; g

roup

2,

info

rmat

ion

to

cise

ben

efite

d su

b-

D

urat

ion:

pr

ogra

m 1

× w

k C

KC

exe

rcis

e w

ith

calc

ulat

e je

cts.

40 m

o x

6 w

k

tape

Fo

llow

-up:

non

eH

arri

son,

24

N =

113

A

ge r

ange

: D

urat

ion:

G

roup

1, h

ome

N

/A: n

o si

gnifi

- A

ll tr

eatm

ents

RC

T A

ttriti

on: 5

4 12

–35

y 3 ×

wk ×

4 w

k ex

erci

se/e

duca

tion;

ca

nt d

iffer

ence

s

effe

ctiv

e an

d

D

urat

ion:

N/A

Fo

llow

-up:

gr

oup

2, tr

aditi

onal

in

VA

S at

1-y

ho

me

exer

cise

3,

6, &

12

mo

PT p

rogr

am; g

roup

3,

follo

w-u

p pr

ogra

m s

houl

d

V

MO

exe

rcis

e,

be

impl

emen

ted

tapi

ng, b

iofe

edba

ck

in

itial

ly; p

rogr

ess

to

mor

e fo

rmal

re

habi

litat

ion

if

need

ed; c

ompr

e-

hens

ive

prog

ram

m

ight

pro

vide

fa

ster

impr

ove-

m

ents

initi

ally

.

Kow

all,25

N

= 2

5 A

ge r

ange

: D

urat

ion:

G

roup

1, s

tand

ard

N

/A: n

o si

gnifi

- N

o ad

ditio

nal b

en-

PR

Attr

ition

: 14

–40

y 2 ×

wk ×

4 w

k PT

inte

rven

tion;

ca

nt d

iffer

ence

s

efit w

ith th

e ad

di-

no

ne r

epor

ted

Dur

atio

n:

Follo

w-u

p: n

one

grou

p 2,

sta

ndar

d

in V

AS

tion

of p

atel

la

1

mon

th–1

5 y

PT

inte

rven

tion

with

tapi

ng.

McC

onne

ll ta

ping

(con

tinue

d)


Mas

chal

,26

N =

2

Age

s: 2

0- &

D

urat

ion:

R

ecru

itmen

t and

U

nabl

e to

com

- Pa

tient

s w

ithC

S A

ttriti

on: n

one

37-y

-old

1–

2 ×

wk ×

en

dura

nce

trai

ning

pu

te s

econ

dary

ab

norm

al lo

wer

wom

en

14 w

k of

hip

, pel

vis,

and

to

exp

erim

enta

l ex

trem

ity k

ine-

Dur

atio

n: 9

&

Follo

w-u

p:

trun

k m

uscl

es

desi

gn

mat

ics

mig

ht

2 y,

res

pect

ivel

y no

ne

bene

fit fr

om a

n

inte

rven

tion

fo

cuse

d on

prox

imal

hip

/

trun

k m

uscl

es.

McM

ulle

n,27

N

= 2

9 A

ge r

ange

: D

urat

ion:

G

roup

1,

cont

rol;

In

suffi

cien

t B

oth

prog

ram

s Q

E A

ttriti

on:

10–4

0 y

3 ×

wk ×

4 w

k gr

oup

2, is

omet

ric

in

form

atio

n pr

ovid

ed

no

ne

Dur

atio

n:

Follo

w-u

p:

exer

cise

; gro

up 3

, to

cal

cula

te

func

tiona

l

1–

8 m

o no

ne

isok

inet

ic e

xerc

ise

im

prov

emen

ts.

Trad

ition

al h

ome

exer

cise

and

Mun

cie

hom

e

ex

erci

se.

Rou

sh,28

N

= 7

7 A

vera

ge a

ge

Dur

atio

n:

Gro

up 1

, hom

e

Insu

ffici

ent

Trad

ition

al h

ome

PR

Attr

ition

: 13

rang

e: 2

2–32

y

hom

e ex

erci

se,

exer

cise

; gro

up 2

, in

form

atio

n

exer

cise

and

D

urat

ion:

N/A

2 ×

d ×

6 w

k;

trad

ition

al P

T

to c

alcu

late

M

unci

e ho

me

tr

aditi

onal

PT,

pr

ogra

m; g

roup

3

ex

erci

se p

rogr

ams

3 ×

wk ×

6 w

k;

Mun

cie

hom

e

be

nefit

ed s

ubje

cts

M

unci

e ex

erci

se,

exer

cise

with

PFP

S.

2 ×

d ×

6 w

k

Follo

w-u

p:

6

& 1

2 w

k af

ter

in

itial

eva

luat

ion

Tabl

e 1

(c

onti

nued

)

Stud

y,

Effe

ct s

ize

type

Sa

mpl

e Pa

rtic

ipan

ts

Dur

atio

n In

terv

enti

on

for

pain

† Im

plic

atio

n


Stie

ne,29

N

= 3

3 A

vera

ge a

ge:

Dur

atio

n:

Gro

up 1

,CK

C

Insu

ffici

ent

Bot

h pr

ogra

ms

QE

Attr

ition

: 10

19 y

3 ×

wk ×

8 w

k ex

erci

se; g

roup

2,

info

rmat

ion

be

nefit

ed s

ubje

cts

Ave

rage

dur

atio

n

Follo

w-u

p:

isok

inet

ic

to c

alcu

late

w

ith P

FPS;

CK

C

ra

nge:

13–

30 m

o 8

& 5

2 w

k af

ter

ex

erci

se

ex

erci

se m

ight

in

itial

eva

luat

ion

prov

ide

addi

tiona

l

fu

nctio

nal b

enefi

ts.

Thom

ee,30

N

= 4

0 A

vera

ge a

ge:

Dur

atio

n:

Gro

up 1

, iso

met

ric

In

suffi

cien

t A

ll su

bjec

ts

RC

T A

ttriti

on: n

one

20 y

3 ×

wk ×

12 w

k ex

erci

se; g

roup

2,

info

rmat

ion

resp

onde

d fa

vor-

Dur

atio

n: >

6 m

o,

Follo

w-u

p:

ecce

ntri

c ex

erci

se

to c

alcu

late

ab

ly to

bot

h

av

erag

e 43

mo

6 &

12

mo

afte

r

(OK

C &

CK

C)

in

terv

entio

ns.

in

itial

eva

luat

ion

Witv

rouw

,31

N =

60

Age

ran

ge:

Dur

atio

n:

Gro

up 1

, OK

C

N/A

: no

sign

ifi-

All

subj

ects

R

CT

Attr

ition

: 14

–33

y 3 ×

wk ×

5 w

k ex

erci

se; g

roup

2,

cant

diff

eren

ces

re

spon

ded

favo

r-

not r

epor

ted

Dur

atio

n:

Follo

w-u

p:

CK

C e

xerc

ise

in V

AS

ably

to b

oth

6 w

k–28

mo

5 w

k &

3 m

o af

ter

inte

rven

tions

.

initi

al e

valu

atio

n

Witv

rouw

,32

N =

60

Age

ran

ge:

Dur

atio

n:

Gro

up 1

, OK

C

N/A

: no

sign

ifi-

All

subj

ects

R

CT

Attr

ition

: 14

–33

y 3 ×

wk ×

5 w

k ex

erci

se; g

roup

2,

cant

diff

eren

ces

re

port

ed d

ecre

ased

not r

epor

ted

Dur

atio

n:

Follo

w-u

p:

CK

C e

xerc

ise

in V

AS

pain

sim

ilarl

y

6

wk–

28 m

o 5

wk

& 3

mo

afte

r

unde

r bo

th in

ter-

in

itial

eva

luat

ion

vent

ions

; no

ch

ange

in r

eflex

re

spon

se ti

mes

.

*QE

indi

cate

s qu

asie

xper

imen

tal;

RC

T, ra

ndom

ized

con

trol

tria

l; V

AS,

vis

ual a

nalo

g sc

ale;

RC

C, r

ando

miz

ed c

ontr

ol c

ompa

riso

n; O

KC

, ope

n ki

netic

cha

in;

CK

C, c

lose

d ki

netic

cha

in; C

S, c

ase

stud

y; P

R, p

rosp

ectiv

e ra

ndom

ized

; PFP

S, p

atel

lofe

mor

al-p

ain

synd

rom

e.†E

ffect

siz

e fo

r pa

in c

hose

n be

caus

e th

is p

aram

eter

was

com

mon

to a

ll st

udie

s an

d is

con

side

red

an im

port

ant i

mpa

irm

ent a

ccor

ding

to th

e Ph

ilade

lphi

a Pa

nel e

vide

nce-

base

d cl

inic

al-p

ract

ice

guid

elin

es.39


including straight-leg raises (SLR), benefit these patients because exercising the knee in a fully extended position minimizes patellofemoral-joint reac-tion forces.23,27 Therefore, these exercises can facilitate quadriceps activation without stressing the patellofemoral joint, because the patella has no contact with the femoral condyles.27

Roush et al28 investigated the efficacy of 3 interventions. One included a home exercise program with traditional “T” SLR exercise and the pillow squeeze (to facilitate quadriceps contraction in combination with hip adduction). Subjects in the second group received weekly physical therapy sessions, which incorporated a combination of open and closed kinetic chain exercises. Subjects in the third group performed an exercise program referred to as the Muncie method, a modification of the traditional SLR exercise. All participants performed the exercises over a 6-week period.

The investigators assessed pain, perceived functional activity, and iso-kinetic knee torque at the beginning of the study, at the end of the 6-week intervention, and 6 weeks after the end of the intervention. They reported that subjects who performed the quadriceps-strengthening home program and Muncie method reported statistically significant improvements regard-ing pain and function.

Roush et al28 concluded that a 6-week intervention using either the home program or Muncie SLR exercise program was effective for patients diag-nosed with PFPS. Eburne and Bannister,22 Thomee,30 and McMullen et al27 found similar results in comparable studies, and subjects in the McMullen study even reported improvement in impairments as soon as 4 weeks after initiating the intervention.

Conclusion/Clinical Implication: Results from these studies demonstrate that patients with PFPS can benefit from isometric quadriceps-strengthening and SLR exercises. It appears that a variety of approaches using isometric and SLR exercises could positively enhance function in these patients.

Isokinetic Exercise

Isokinetic exercise differs from isometrics in that it allows subjects to move the tibia over the femur through a specified range of motion at a constant velocity. This form of open kinetic chain (OKC) exercise has been used in traditional PFPS rehabilitation,23 and researchers have investigated the effect of isokinetic exercise in decreasing impairments associated with patients with PFPS.

Alaca et al18 investigated this effect in symptomatic subjects who partici-pated in a 6-week (3 sessions a week) isokinetic training program. Subjects performed 3 sets of 10 repetitions at angular speeds of 60°/s and 180°/s and reported no pain during exercise sessions. Results from this study demon-strated that subjects had statistically significant decreases in pain, increases in functional-testing scores, and increases in peak torque, total work, and


power at 60°/s and 180°/s. The researchers concluded that isokinetic exer-cise can promote extensor-mechanism strength in a pain-free manner.

McMullen et al27 also reported subject improvement with isokinetic exercise. Their study implemented a 2-phase program. Phase I included low-speed (30°, 60°, 90°, and 120°/s), short-arc (30° to 0°) angular veloci-ties. Subjects then progressed to phase II, which incorporated high-speed (180°, 240°, and 300°/s), full-arc (90° to 0°) exercises if subjects could do them without pain. The researchers did not report how many subjects pro-gressed to phase II but stated that patients who could not tolerate this phase continued working at the phase I program. This finding suggests that some subjects did not tolerate a more aggressive isokinetic program.

Based on the McMullen study, clinicians should consider the potential for excessive pressure when performing active exercise near terminal knee extension. Steinkamp et al33 reported increased patellar pressure over a smaller contact area as the knee moved toward terminal extension during OKC exercise. These findings imply that some patients with PFPS might not tolerate a full-range-of-motion isokinetic-exercise program.

Conclusion/Clinical Implication: Results from these studies demonstrate that patients with PFPS can benefit from isokinetic exercise. Oftentimes, 3 sets of 10 repetitions at 2 or 3 speeds have been used successfully, but clini-cians should use caution to ensure that patients can perform all exercise in a pain-free range of motion.

Closed Kinetic Chain ExerciseMany clinicians prefer closed kinetic chain (CKC) exercise because of its functional manner and decreased stress to the patellofemoral joint, par-ticularly in the terminal ranges of 40° to full extension.34 Steinkamp et al33 documented the fact that patellofemoral joint-reaction forces are minimized during CKC exercise performed from 0° to 40° of knee flexion. They think that patients with PFPS might tolerate a CKC rehabilitation program, performed from 0° to 40° knee flexion, better than one focusing on OKC exercise, because of lower patellofemoral-joint stresses.

Witvrouw et al31 evaluated the efficacy of OKC versus CKC exercise in patients with PFPS. Sixty subjects participated in this study and were ran-domly assigned to either the OKC or CKC group. All subjects performed the rehabilitation program for 5 weeks and were evaluated at the beginning of the study, immediately after the end of the rehabilitation intervention, and 3 months after the beginning of the study. The researchers evaluated patients using the Kujala patellofemoral scale, functional tests, isokinetic muscle-strength testing, and flexibility measures. They reported that sub-jects in both groups improved functionally, and they found no differences in the amount of improvement between the 2 groups.


Stiene et al29 compared the effects of CKC and isokinetic exercise in patients diagnosed with PFPS. Subjects performed the prescribed exer-cise regimen for an 8-week period and were assessed periodically over a 1-year period. Although only 70% of the subjects participated in the final assessment, the researchers found that all had improved with respect to strength measures. Subjects who participated in the CKC-exercise program, however, scored higher on measures related to functional improvements and perceived functional status.

Thomee30 compared isometric exercise with exercise focusing on eccen-tric muscle contractions. Subjects in the first group performed a program that emphasized isometric contractions, whereas those in the second group performed a program that focused on eccentric contractions during OKC and CKC exercises. All subjects reported a decline in pain level and dem-onstrated improved knee-torque measurements, vertical-jumping ability, and physical activity level at the end of a 12-week intervention. The author concluded that no difference existed between the effectiveness of the 2 exercise programs.

Conclusion/Clinical Implication: Results from these studies demonstrate that patients with PFPS can benefit from both OKC and CKC exercise. Clini-cians must consider the biomechanical influences of joint position and the effect on patellofemoral-joint stresses. A key point is that patients perform all exercises in a pain-free manner. If patients are unable to tolerate CKC exercise, then OKC exercise might be a viable option. Selection of range of motion will dictate whether open (40° to 90° flexion) or closed (0° to 40° flexion) kinetic chain might be most appropriate.

BiofeedbackMany clinicians use biofeedback in combination with exercise to facili-tate quadriceps activity. Biofeedback is thought to help patients develop improved voluntary control over quadriceps activation.21 Although many researchers have reported increased quadriceps activity using this modality in healthy subjects,35-37 fewer studies have specifically examined the benefits of biofeedback for patients with knee pathology.21

Dursun et al21 investigated the relationship between biofeedback, exercise, and quadriceps function in patients with PFPS. Sixty subjects participated in the study and were assigned to 1 of the following groups: biofeedback and exercise or exercise only. All subjects performed a traditional exercise program 5 days a week for 4 weeks and then 3 days a week for another 8 weeks. The exercise program consisted of isometric strengthening, as well as flexibility, proprioceptive, and endurance training.

The researchers measured changes in visual-analog-scale (VAS) scores, Functional Index Questionnaire (FIQ) scores, and mean quadriceps contraction at the end of each month. VAS and FIQ scores improved


significantly for both groups at each measurement interval. Subjects in the biofeedback group also demonstrated significant increases in mean quadriceps-contraction values when compared with those in the exercise group. Although the researchers found statistically significant increases in certain mean quadriceps-contraction values, these findings might lack clinical significance because of effect sizes ranging from .27 to .33. Cohen38 has interpreted this range as representing a small effect size.

The diagnosis of PFPS depends primarily on a patient’s subjective his-tory of pain and functional limitations3; therefore, the effectiveness of an intervention might rely more on changes in patient complaints.39 All subjects in the Dursun et al study21 demonstrated equally significant improvements on VAS and FIQ scores. Based on these improvements, the authors con-cluded that biofeedback did not result in clinical improvement beyond that of traditional exercise alone.

Conclusion/Clinical Implication: Biofeedback might not provide benefit for patients with PFPS additional to that of exercise alone. Clinicians should consider the cost:benefit ratio when deciding whether or not to use bio-feedback in the rehabilitation process.

McConnell-Based Patella TapingSoft-tissue structures, quadriceps activity, and neuromotor systems can affect patella tracking, and imbalances of any of these factors can contribute to abnormal patella tracking.

Historically, practitioners have hypothesized that vastus medialis oblique (VMO) and vastus lateralis (VL) muscle-activation timing differ-ences might lead to abnormal lateral patella tracking and PFPS.1,40-42 They think that techniques that can decrease VMO/VL timing differences by improving patella tracking might decrease PFPS symptoms.

McConnell43 has advocated the use of patella taping to promote pain-free exercise for patients with PFPS, reporting that patella taping places the patella in a more medial position and decreases compressive forces caused by excessive lateralization. McConnel has reported success rates as high as 96% in patients with PFPS who performed exercise in combination with this taping technique.

Eburne and Bannister22 compared the McConnell regimen with an isometric quadriceps-exercise program in patients with PFPS. One group of subjects performed quadriceps isometric and SLR exercises; subjects in the other group performed VMO-strengthening exercises with McConnell taping. All participants performed the exercises over a 3-month period. The researchers measured improvements using a VAS, McConnell critical test, and a modified Clark test. At the end of the 3-month period, subjects in both groups demonstrated improvements in these parameters, and sta-tistical analyses did not reveal any between-group differences. Overall, the


results showed that both exercise programs benefited all patients by 50%, far less than the 96% success rate reported by McConnell.43

Clark et al19 conducted a randomized controlled trial that examined the effect of exercise, patient education, and taping on strength, pain, and func-tion in patients diagnosed with PFPS. The researchers assigned participants to 1 of the following intervention groups: exercise, taping, and education; exercise and education; taping and education; and education regarding the etiology and prevention of further knee irritation (shoe wear, ice, stress relaxation, and diet/weight advice). Subjects assigned to the exercise groups performed activities that resulted in strong eccentric contractions of the lower limb extensors (gluteal and quadriceps muscles). These subjects performed wall squats, step-downs, and proprioceptive balance work on a minitramp daily and were monitored by the investigators 6 times over a 3-month period. Subjects assigned to the taping groups were instructed in tape application in which they applied the tape from the lateral border of the patella, pulling upward and medially over the medial femoral condyle.

The researchers measured pain, perceived function, and strength before the intervention and at 3 and 12 months after the beginning of the study. All subjects demonstrated improvements in all parameters at the 3-month retesting period. In addition, those in the exercise and education groups achieved greater strength gains than did subjects who only did taping. For the 12-month retesting, the researchers sent a questionnaire on pain and perceived function. Sixty-nine percent of subjects responded, and results showed that subjects who performed exercises had significantly lower pain scores and higher perceived function. The researchers concluded that taping did not add greater value than exercise alone.

Kowall et al25 reported similar results in their study examining the efficacy of patella taping in the conservative management of PFPS. Two groups of subjects performed identical exercises 2 times a week for 4 weeks in addition to a daily home-exercise program. Groups differed only in that 1 group performed the exercises with McConnell taping. Dependent variables included VAS scores, isokinetic knee peak-torque values, and integrated EMG for the VMO and VL. At the end of the study, all subjects demonstrated a decrease in symptoms, although there was no difference between groups. The researchers also reported similar findings with respect to the isokinetic and EMG parameters. They concluded that the addition of patella taping to a standard physical therapy program did not alter outcomes for subjects in either group.

As mentioned previously, many investigators have reported VMO/VL timing differences that might contribute to abnormal patella tracking. Although some researchers believe that timing differences exist and that taping can affect them,41 other researchers have not reported VMO/VL timing differences in patients with PFPS.32,44,45 Findings from the preceding studies suggest that exercise can increase quadriceps strength, decrease


pain, and improve function, but the role of patella taping remains elusive. Further studies should examine this phenomenon.

Conclusion/Clinical Implication: Taping has been a popular treatment modality for patients diagnosed with PFPS, and researchers have examined the efficacy of taping in combination with exercise. Results from the current review of the literature support the notion that the exercise component, and not necessarily the tape application, benefited patients with PFPS. These findings imply that further research is needed in determine the therapeutic effects of patella taping.

Combination of TreatmentsOther researchers have examined the efficacy of physical therapy interven-tion on patients with PFPS using a combination of the preceding techniques. Harrison et al24 studied 3 treatment approaches: 1) a home strengthening and flexibility program, 2) a physical therapist–monitored program (3 times a week for 4 weeks) similar to group 1’s home exercise program, and 3) a comprehensive exercise program that employed biofeedback and patella taping. The researchers monitored pain, perceived function, and strength over a 1-year period. Results from this study showed that subjects in the comprehensive treatment program attained more improvement in impair-ments initially at the first 3-month retesting date. Long-term evaluation, however, indicated that all subjects benefited from their particular interven-tions and that no difference existed between groups regarding the amount of improvement.

Crossley et al20 conducted a randomized, placebo-controlled trial study-ing the effectiveness of physical therapy interventions. These researchers also used a combination of all interventions discussed previously. This study differed from that of Harrison et al24 in that 1 group of subjects received a placebo intervention. Specifically, the treatment group participated in a program consisting of patella taping, VMO biofeedback, gluteal strength-ening, and soft-tissue stretching. Those in the placebo group received pla-cebo taping, sham ultrasound, and light application of a nontherapeutic gel. To determine differences between groups, the researchers examined VAS scores, FIQ scores, anterior knee-pain scores, and patients’ perceived response to treatment. At the end of the 6-week intervention, subjects receiving the “true” intervention demonstrated a greater reduction in the parameters measured. Results from this study had high effect sizes38 related to the VAS and anterior knee-pain scores (ranges from .75 to .91), although the FIQ scores had a small effect size (.33).

Although the Crossley et al20 study provided evidence on the efficacy of physical therapy, it might not provide additional information regarding the most effective intervention. Many researchers9,29-31 have established a relationship between quadriceps strengthening and decreased impairments


in patients with PFPS. This study employed exercise and other techniques. One might infer that exercise contributed the most to reducing the patients’ symptoms. Therefore, additional randomized clinical trials that can make direct comparisons between specific interventions would provide much-needed evidence regarding the most important intervention strategy.

Conclusion/Clinical Implication: All of the research findings discussed throughout this review support the findings of the Harrison et al24 and Crossley et al20 studies. A potential flaw with these “combination of treat-ment” studies relates to the difficulty in drawing definitive conclusions regarding which part of the rehabilitation program might be the most beneficial.

Influences From Hip MusculatureInformation has recently been reported on a relationship between proxi-mal hip-muscle weakness and the incidence of PFPS.26,46 Although few researchers have provided quantitative data on proximal hip weakness in the PFPS population, clinicians have included gluteal strengthening as part of a comprehensive PFPS intervention.3,19,20,26,28

Powers et al47 have provided information that patellofemoral-joint kine-matics differ during weight-bearing and non-weight-bearing lower extrem-ity positions. Using kinematic magnetic-resonance imaging, they found that the patella rotates on the femur during non-weight-bearing knee-extension exercise. Alternatively, they described patellofemoral-joint kinematics as the femur rotating underneath the patella during weight-bearing knee-extension exercise. Findings from this study support the influence of the proximal hip musculature’s role in controlling femoral internal rotation. In addition, Powers et al48 have reported that subjects with PFPS demonstrated less femoral internal rotation than did subjects in a control group during normal gait and speculated that the PFPS subjects maintained less femoral internal rotation to decrease the Q angle.

Mascal et al45 recently reported on the effectiveness of an intervention that focused on the hip, pelvis, and trunk muscles. Dependent variables examined included pain, functional status, quadriceps and hip strength, PFPS-provocation tests (apprehension test and patella compression), and an observational gait assessment for 2 subjects. In addition, the research-ers performed motion analysis on 1 subject to determine changes in lower extremity kinematic factors.

The subjects participated in a progressive 14-week exercise program. Both reported improvements in all measured variables. Furthermore, the subject who underwent motion analysis demonstrated a 1.2° decrease in femoral internal rotation and a 5.4° decrease in ipsilateral hip adduction after participating in the intervention. The researchers concluded that both


subjects responded favorably to the treatment and that factors proximal to the knee might influence PFPS pain. Although this study was only a report of 2 case studies, it has provided important information regarding the direc-tion in which researchers might focus new investigations.

Conclusion/Clinical Implication: Investigations relating to the role of the musculature proximal to the knee are limited. Clinicians have inferred that the hip might contribute to PFPS but without specific data to support this theory. Current studies26,49 support the role of hip stabilization with respect to knee pathology; however, additional studies are needed to better under-stand this relationship.

Conclusion

This review of the literature supports the idea that a variety of strengthening exercises have a therapeutic effect on subjects with PFPS. Although clini-cians might have a bias toward either OKC or CKC exercise, either type of exercise can benefit this patient population, particularly when applied in pain-free and appropriately matched portions of the range of motion. Clinicians have also popularized the use of biofeedback and patella taping; however, limited research has supported these interventions. In summary, this literature review has compiled relevant clinical findings that clinicians can use to facilitate the decision-making process in prescribing an interven-tion founded on sound scientific data for this patient population.

Table 1 presents the summarized findings of the selected articles that met our inclusion criteria (published in peer-reviewed journals in the last 20 years and having a clinical intervention of at least 4 weeks related to patients with patellofemoral-pain syndrome). To give meaning to these interventions, a calculated effect size was generated in an attempt to dem-onstrate the level of impact seen in each study, which might serve as a guide to intervention selection for patients with this condition.

References

1. Doucette SA, Goble EM. The effect of exercise on patellar tracking in lateral patellar compression syndrome. Am J Phys Med Rehabil. 1992;20(4):434-440.

2. Heinjes E, Berger MY, Bierma-Zeinstra SMA, Bernsen RMD, Verhaar JAN, Koes BW. Exercise therapy for patellofemoral pain syndrome. In: The Cochrane Library. Vol 1. Chichester, UK: John Wiley & Sons, Ltd; 2004.

3. Fulkerson JP. Diagnosis and treatment of patients with patellofemoral pain. Am J Sports Med. 2002;30(3):447-456.

4. Crossley K, Bennell K, Green S, McConnell J. A systematic review of physical interventions for patellofemoral pain syndrome. Clin J Sports Med. 2001;11:103-110.


5. Bizzini M, Childs JD, Piva SR, Delitto A. Systematic review of the quality of randomized controlled trials for patellofemoral pain syndrome. J Orthop Sports Phys Ther. 2003;33(1):4-20.

6. Thomee R, Renstrom P, Karlsson J, Grimby G. Patellofemoral pain syndrome in young women, II: muscle function in patients and healthy controls. Scand J Med Sci Sports. 1995;5:245-251.

7. Malone TR, Davies GJ, Walsh WM. Muscular control of the patella. Clin Sports Med. 2002;21(3):349-362.

8. Powers CM. Patellar kinematics, part I: the influence of the vastus muscle activ-ity in subjects with and without patellofemoral pain. Phys Ther. 2000;80(10):956-964.

9. Natri A, Kannus P, Jarvinen M. Which factors predict the long-term outcome in chronic patellofemoral pain syndrome? a 7-yr prospective follow-up study. Med Sci Sports Exerc. 1998;30:1572-1577.

10. Gryzlo SM, Patek RM, Pink M, Perry J. Electromyographic analysis of knee rehabilitation exercises. J Orthop Sports Phys Ther. 1994;20(1):36-43.

11. Isear JA, Erickson JC, Worrell TW. EMG analysis of lower extremity muscle recruitment patterns during an unloaded squat. Med Sci Sports Exerc. 1997;29(4):532-539.

12. Laprade J, Culham E, Brouwer B. Comparison of five isometric exercises in the recruitment of the vastus medialis oblique in persons with and without patellofemoral pain syndrome. J Orthop Sports Phys Ther. 1998;27(3):197-204.

13. Matheson JW, Kernozek TW, Fater DCW, Davies GJ. Electromyographic activ-ity and applied load during seated quadriceps exercises. Med Sci Sports Exerc. 2001;33(10):1713-1725.

14. Selseth A, Dayton M, Cordova ML, Ingersoll CD, Merrick MA. Quadriceps concentric EMG activity is greater than eccentric EMG activity during the lateral step-up exercise. J Sport Rehabil. 2000;9(2):124-134.

15. Zakaria D, Harburn KL, Kramer JF. Preferential activation of the vastus medialis oblique, vastus lateralis, and hip adductor muscles during isometric exercises in females. J Orthop Sports Phys Ther. 1997;26(1):23-28.

16. Portney LG, Watkins MP. A concept of research. In: Foundations of Clinical Research. Applications to Practice. 2nd ed. Upper Saddle River, NJ: Prentice Hall Health; 2000:3-20.

17. Davies GJ, Heiderscheit BC, Manske RC, Neitzel J. The scientific and clinical rationale for the integrated approach to open and closed kinetic chain reha-bilitation. Orthop Phys Ther Clin North Am. 2000;9(2):247-267.

18. Alaca R, Yilmaz B, Goktepe AS, Mohur H, Kalyon TA. Efficacy of isokinetic exercise on functional capacity and pain in patellofemoral pain syndrome. Am J Phys Med Rehabil. 2002;81(11):807-813.

19. Clark DI, Downing N, Mitchell J, Coulson L, Syzpryt EP, Doherty M. Physio-therapy for anterior knee pain: a randomised controlled trial. Ann Rheum Dis. 2000;59:700-704.

20. Crossley K, Bennell K, Green S, Cowan S, McConnell J. Physical therapy for patellofemoral pain. a randomized, double-blinded, placebo-controlled trial. Am J Sports Med. 2002;30(6):857-865.


21. Dursun N, Dursun E, Kilic Z. Electromyographic biofeedback—controlled exer-cise versus conservative care for patellofemoral pain syndrome. Arch Phys Med Rehabil. 2001;82:1692-1695.

22. Eburne J, Bannister G. The McConnell regimen versus isometric quadriceps exercises in the management of anterior knee pain. A randomised prospective controlled trial. Knee. 1996;3:151-153.

23. Gaffney K, Fricker P, Dwyer T, Barrett E, Skibinski K, Coutts R. Patellofemoral joint pain: a comparison of two treatment programmes. Excel. 1992;8:179-189.

24. Harrison EI, Sheppard MS, McQuarrie AM. A randomized controlled trial of physical therapy treatment programs in patellofemoral pain syndrome. Phys-iother Can. 1999;51(2):93-100.

25. Kowall MG, Kolk G, Nuber GW, Cassisi JE, Stern SH. Patellar taping in the treatment of patellofemoral pain. a prospective randomized study. Am J Sports Med. 1996;24(1):61-66.

26. Mascal CL, Landel R, Powers C. Management of patellofemoral pain targeting hip, pelvis, and trunk muscle function: 2 case reports. J Orthop Sports Phys Ther. 2003;33(11):647-660.

27. McMullen W, Roncarati A, Koval P. Static and isokinetic treatments of chon-dromalacia patella: a comparative investigation. J Orthop Sports Phys Ther. 1990;12(6):256-266.

28. Roush MB, Sevier TL, Wilson JK, Jenkinson DM, Helfst RH, Gehlsen GM, Basey AL. Anterior knee pain: a clinical comparison of rehabilitation methods. Clin J Sports Med. 2000;10:22-28.

29. Stiene HA, Brosky T, Reinking MF, Nyland J, Mason MB. A comparison of closed kinetic chain and isokinetic joint isolation exercise in patients with patellofemoral dysfunction. J Orthop Sports Phys Ther. 1996;24(3):136-141.

30. Thomee R. A comprehensive treatment approach for patellofemoral pain syn-drome in young women. Phys Ther. 1997;77(12):1690-1703.

31. Witvrouw E, Lysens R, Bellemans J, Peers K, Vanderstraeten G. Open versus closed kinetic chain exercises for patellofemoral pain. Am J Sports Med. 2000;28(5):687-694.

32. Witvrouw E, Cambier D, Danneels L, Bellemans J, Werner S, Almqvist F, Verdonk R. The effect of exercise regimens on reflex response time of the vasti muscles in patients with anterior knee pain: a prospective randomized intervention study. Scand J Med Sci Sports. 2003;13(4):251-258.

33. Steinkamp LA, Dillingham MF, Markel MD, Hill JA, Kaufmen KR. Biome-chanical considerations in patellofemoral joint rehabilitation. Am J Sports Med. 1993;21:438-446.

34. Rivera JE. Open versus closed kinetic chain rehabilitation of the lower extrem-ity: a functional and biomechanical analysis. J Sport Rehabil. 1994;3:154-167.

35. Davlin CD, Holcomb WR, Guadagnoli MA. The effect of hip position and electromyographic biofeedback on the vastus medialis oblique: vastus lateralis ratio. J Athl Train. 1999;34(4):342-349.

36. Campenella B, Mattacola CG, Kimura IF. Effect of visual feedback and verbal encouragement on concentric quadriceps and hamstrings peak torque of males and females. Isokinet Exerc Sci. 2000;8(1):1-6.

88 Bolgla and Malone

37. Kim HJ, Kramer JF. Effectiveness of visual feedback during isokinetic exercise. J Orthop Sports Phys Ther. 1997;26(6):318-323.

38. Cohen J. Statistical Power Analysis for Behavioral Sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum; 1988.

39. Philadelphia Panel. Philadelphia Panel evidence-based clinical practice guidelines on selected rehabilitation interventions for knee pain. Phys Ther. 2001;81(10):1675-1700.

40. Voight ML, Wieder DL. Comparative reflexive response times of VMO and VL in normal subjects and subjects with extensor mechanism dysfunction. Am J Sports Med. 1991;19(2):131-137.

41. Cowan SM, Bennell KL, Hodges PW. Therapeutic patellar taping changes the timing of vasti muscle activation in people with patellofemoral pain syndrome. Clin J Sports Med. 2002;12:339-347.

42. Cowan SM, Bennell KL, Hodges PW, Crossley KM, McConnell J. Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome. Arch Phys Med Rehabil. 2001;82:183-189.

43. McConnell J. The management of chondromalacia patella: a long-term solution. Aust J Physiol. 1986;32:215-223.

44. Owings TM, Grabiner MD. Motor control of the vastus medialis oblique and vastus lateralis muscles is disrupted during eccentric contractions in subjects with patellofemoral pain. Am J Sports Med. 2002;30(4):483-487.

45. Powers CM, Landel R, Perry J. Timing and intensity of vastus muscle activity during functional activities in subjects with and without patellofemoral pain. Phys Ther. 1996;76(9):946-955.

46. Ireland ML, Willson JD, Ballantyne BT, Davis IM. Hip strength in females with and without patellofemoral pain. J Orthop Sports Phys Ther. 2003;33(11):671-676.

47. Powers CM, Ward SR, Fredericson M, Guillet M, Shellock FG. Patellofemoral kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella: a preliminary study. J Orthop Sports Phys Ther. 2003;33(11):677-685.

48. Powers CM, Chen PY, Reischl SF, Perry J. Comparison of foot rotation and lower extremity rotation in persons with and without patellofemoral pain. Foot Ankle Int. 2002;23(7):634-640.

49. Fredericson M, Cookingham CL, Chaudhari AM, Dowdell BC, Oestreicher N, Sahrmann SA. Hip abductor weakness in distance runners with iliotibial band syndrome. Clin J Sports Med. 2000;10:169-175.

Documents

Exercise Prescription and Patellofemoral Pain 73 … · focused on VMO with lateral patel-group 3, 16 ± strengthening 2.6 y ... referred to as the Muncie method, a modification of