1. Research Report
Comparison of the Effects of Exercise in Water and
on Land on the Rehabilitation of Patients With
Intra-articular Anterior Cruciate Ligament
Reconstructions
Background and Purpose. Exercises in water have been shown to be effective Brlan J Tovln
for improving strength and passive range of motion (PROM). Traditional rehabili- Steven L Wolf
tation following intra-articular anterior cruciate ligament (ACL) reconstruction Bruce H Greenfield
has taken place o n land. This study was designed to compare the effects of exer- Jerl Crouse
cises in water o n strengh and girth of the thgb musculature, knee PROM, joint Blane A Woodfin
laxity, e m i o n , and functional outcome with the effects of similar mercises o n
land in subjectsfollowing intra-articular reconstruction of the ACL. Subjects.
Twenty subjects were randomly asstgned to either a group that exercised o n land
or a group that exercised i n water. Metbods. Thigh girth, joint effm'on, and knee
PROM measurements were recorded at 2-week intervalsfor the first 8 weeks post-
operatively. Isokinetic and isometric peak torque measurementsfor the thigh mus-
culature, knee joint laxity assessments, and Lysholm scores were obtained at the
end of 8 weeks. Results. Higher outcome scores were recorded in the water
group than in the landgroup, as measured by Lysholm scales. No dtferences were
noted between groups for knee PROM, thigh girth, or quadriceps femoris muscle
p e r f o m w e . In the water group, lessjoint e f m o n was noted aJer the 8 weeks.
In the land group, greater peak torquefor isokinetic knee flexion was recorded.
Concluston and Discussion. Although exercise in water may not be as effec-
tive as exercise o n land for regaining maximum muscle perfomnce, rehabilita-
tion in water may minimize the amount of joint effiion and lead to greater
self-reportsof functional improvement in subjects with intra-articular ACL recon-
structions. [Tovin BJ, Wolf SL, Greenfield BH, et al. Comparison of the effects of
exercise in water and o n land o n the rehabilitation of patients with intra-
articular anterior cruciate ligament reconstmctions. Phys Ther.
199g 74: 710-719.1
Key Words: Knee; Ligaments; Lower extremity, knee; Muscle pe$omance, lower
extremity; Rehabilitation.
Rehabilitation following anterior cru- have influenced rehabilitation, as have months.2 Primary goals continue to be
ciate ligament (ACL) reconstruction knowledge of stress-strain patterns in the recovery of joint range of motion
has evolved over the past few decades the ACL during various exercises.2 (ROM), quadriceps femoris muscle
and is considered important in guar- Twelve-month protocols requiring force-generating capability, and ambu-
anteeing a beneficial outcome follow- immobilization and non-weight bear- latory skills.2 Attaining these goals,
ing surgety.1 Advances in surgical ing3 have given way to accelerated however, may be delayed by postop-
approaches, such as graft placement protocols permitting immediate erative joint effusion and the persis-
and graft fixation, and the use of ar- weight bearing, no immobilization, tence of pain. Early phases of rehabili-
throscopically assisted procedures and return to activity within 6 tation must minimize the deleterious
22/710 Physical Therapy/Volume 74, Number B/August 1994

2. effects of surgery through ROM and impairments of patients following ACL more effective in retarding thigh atro-
muscle strengthening exercises while reconstruction, research suggests that phy than traditional rehabilitation
ensuring that each activity is per- closed-chain exercises are safer than alone. Thigh atrophy, however, is only
formed without overstressing the ACL open-chain exercises because there is one measure of recovery. Whether
grafts.435 less stress on the graft.11-13 Despite rehabilitation in water will be differ-
this fact, some subjects experience ent from traditional rehabilitation in
Electromyographic biofeedback5j6 and increased pain and knee effusion reducing knee joint laxity, enhancing
neuromuscular electrical stimulation7.8 following closed-chain exercises.14 muscle force, and improving func-
are two modalities used in the early Therefore, performing closed-chain tional outcomes in subjects with intra-
phases of rehabilitation following ACL exercises in an environment in which articular ACL reconstructions is
reconstruction to reduce muscle atro- the forces around the knee joint are uncertain.
phy and to facilitate strengthening. reduced may aid in reducing knee
The effectiveness of these modalities pain and joint effusion. The purpose of this study was to
in imprc~ving quadriceps femoris determine whether exercises in a
muscle force in subjects with ACL Fkercises in water could expedite pool will lead to less joint effusion,
reconstruction has been measured by rehabilitation because of the de- less thigh atrophy, increased ROM
isokinetic dynomometry.6~7 These creased stress on the joints, improved and thigh musculature strength, and
studies, however, applied feedback o r circulation, and facilitated movement less difficulty with activities of daily
neuroml~scularelectrical stimulation that occur in water.15.16 Researchers living in patients after intra-articular
during isometric quadriceps femoris have analyzed limb movement in ACL reconstruction compared with
exercises, and this approach may not water17-'9 and have compared differ- exercises on land. An effort was made
simulate functional activities. ent aquatic exercise devices,2&22but to match specific exercises in both
few studies have quantified gains in groups so that each program was
We believe knee extension exercises muscular force that occur following identical and only the rehabilitation
should be designed to simulate func- an aquatic exercise program. Bartow environment was manipulated.
tional activities. "Closed-chain" knee and Diamond23 have concluded that
extension has been advocated as a exercises performed using water as Method
safe exercise for patients after ACL resistance can increase the torque-
reconstruction.9 These exercises in- generating capabilities of the thigh Subjects
volve applying resistance through the musculature in healthy subjects.
terminal joint of a limb segment, Gehlsen et a124 have made similar Twenty subjects (14 male, 6 female)
which restrains the joint's free move- conclusions in patients with multiple ranging in age from 16 to 44 years
ment (eg, rising from a chair), sclerosis, but no control group was @=29.0, SD=7.8) participated in this
whereas "openchain" exercises in- used for comparison. study. All subjects had undergone
volve applying resistance to an ex- arthroscopically assisted intra-articular
tremity in a way that the distal joint is NapoletanZ5found that in subjects ACL reconstruction using a bone-
free to move (eg, kicking into the with ACL reconstructions, underwater patellar tendon-bone autograft, per-
air).IO Although both of these forms of treadmill ambulation in conjunction formed by the same orthopedic sur-
exercise can address the physical with traditional rehabilitation was geon. Subjects who had prior ACL
surgery to either knee or who had a
meniscus repair at the time of surgery
were excluded from the study.
BJ Tovin, IT, ATC, is StafT Physical Therapist, Physiotherapy Associates, 2770 Lenox Rd NE, Ste 102,
Atlanta, GA 30324 (USA), and Director of Rehabilitation, Georgia Tech Athletic Association, Atlanta, Procedure
GA 30332. Mr Tovin was a student at Emory University, Atlanta, GA, at the time this study was com-
pleted in partial fulfillment of the requirements for his Master of Medical Science degree. Address
all correspondence to Mr Tovin. During the preoperative visit, subjects
SL Wolf, PhD, FT,FAlTA, is Professor and Director of Research, Department of Rehauilitation Medi-
were familiarized with the study and
cine, Professor, Division of Geriatrics, Department of Internal Medicine, and Associate Professor, postoperative rehabilitation protocols
Department of Anatomy and Cell Biology, Emory University School of Medicine, 1441 Clifton Rd were explained. Each subject signed
NE, Atlanta, GA 30322.
an informed consent statement, writ-
BH Greenfield, FT,OCS, is Clinical Coordinator of Education and Clinic Director, Physiotherapy Associ- ten to conform with the guidelines of
ates, Jonestmro, GA 30236, and Clinical Instructor, Division of Physical Therapy, Emory University. Emory University and Piedmont Hos-
J Crouse, IT, is Clinical Coordinator of Physical Therapy, HealthSouth, Atlanta, GA 30342. pital (Atlanta, Ga), and a questionnaire
was administered. Subjects were as-
BA Woodfin, MD, is Orthopaedic Surgeon, Resurgeons Orthopaedics, and Team Physician, Georgia
Tech Athletic Association.
signed to either a traditional rehabili-
tation (TR) group or a pool rehabilita-
This study was approved by the Human Investigation Committee of Emory University and Pied- tion (PR) group using the following
mont Hospital.
method of group assignment. The first
This article was submitted April 13, 1993, and was accepted Januaty 6, 194. 2 subjects were randomly assigned to
Physical Therapy /Volume 74, Number 8/August 1994

3. -
Table 1 . Rehabilitation Pmgrams
Week 1 and Home Program Exercises (Both Groups)
1. Wall slides: 25 repetitions
2. Active-assistive range of motion: 25 repetitions
--
3. Passive knee extension: 10 minutes
4. Hamstring muscle and calf stretching: 10 minutes each
5. Quadriceps femoris muscle sets
6. Straight leg raisesa: 3 sets x 10 repetitions for hip flexion, abduction, adduction, and extension
7. Active knee flexiona: 3 sets x 10 repetitions
8. Toe raises: 3 sets x 10 repetitions
9. Partial wall squats (usually added to the home program after first week): 3 sets x 10 repetitions
Week 2-8 Exercise Programs
Traditional Rehabilitation Group Pool Rehabilitation Group
1. Stationary cycling: 10 minutes 1. Stationary cycling: 10 minutesb
2. Gait training without brace, alternating forward and backward 2. Gait training without brace, alternating forward and backward
ambulation: 10 min ambulation: 10 min
3. Side step-ups, front step-ups, step-downs: beginning with 3 sets 3. Side step-ups, front step-ups, step-downs: beginning with 3 sets of
of 10 repetitions, progressing to 3 sets of 15 repetitions 10 repetitions, progressing to 3 sets of 15 repetitionsC
4. Hip flexion, extension, abduction, adduction in standing using a 4. Hip flexion, extension, abduction, adduction in standing using the
wall pulley with 4.54-kg (10-lb) plates: beginning with 3 sets of 10 Hydrotone resistance boot: beginning with 3 sets of 10 repetitions
repetitions, progressing to 3 sets of 15 repetitions and progressing to 3 sets of 15 repetitions
5. Knee flexion in sitting: 3 sets of 10 repetitions; boot: beginning 5. Knee flexicn in standing using the Hydrotone resistance boot:
with 3 sets of 10 repetitions, progressing to 3 sets of 15 repetitions beginning with 3 sets of 10 repetitions and progressing to 3 sets of
15 repetitions
"Cuff weights were added to straight leg raises and knee flexion in increments of 0.91 kg (2 lb).
*stationary cycling in the pool rehabilitation group used a peddling device (see Fig. 1) rather than a stationary bicycle.
'Step-ups in the water were done with 20.32-cm (8-in) and 40.64-cm (16-in) steps.
one of the two groups using a coin which one of the authors reviewed how to keep a log of their home
toss. The next 2 subjects recruited the home program to ensure that the exercise p r o g m , which was checked
were placed in opposite groups of the exercises were done safely and inde- by one of the authors to help assess
first 2 subjects. This procedure was pendently. To facilitate passive knee compliance.
continued for every 4 subjects until extension, each subject was posi-
20 subjects were recruited. As a result, tioned prone and the involved leg Weight Bearing
6 men and 4 women were placed in (from the superior third of the tibia
the P group and 8 men and 2
R to the foot) was placed off the side of Gait training was also initiated on the
women were placed in the TR group. a treatment table or bed, letting grav- first postoperative session with axil-
This method of group assignment was ity pull the knee into extension. Resis- lary crutches and a hinged knee
used to evenly distribute subjects tance for the straight leg raises and brace. The braces were locked in full
between the two groups over time, leg curls was added using variable- extension for the first 4 to 7 days, and
while also incorporating random resistance cuff weights. Subjects initi- subjects were instructed to bear as
assignment to groups. ated each exercise, performing three much weight as they could tolerate.
sets of 10 repetitions without weight Subjects were progressed from two
Week 1 Exercises for Both and progressing until they could per- crutches to one crutch between the
Oroups form three sets of 15 repetitions with- 4th and 7th postoperative days and
out difficulty. Subjects then added 0.9 were usually off the crutch by the
During the first postoperative session, kg (2 lb) to the cuff weight and re- 10th postoperative day. The hinged
patients in both groups were in- peated the progression starting with knee brace was unlocked at the be-
structed in an identical program (Tab. three sets of 10 repetitions. This pro- ginning of the 2nd week, permitting
I), which they performed at home cedure was continued, and resistance 90 degrees of knee flexion. The ROM
twice per day. The first week of post- was added in 0.9-kg increments (most of the braces were increased to 120
operative rehabilitation consisted of patients progressed their weight every degrees by the beginning of the 3rd
three o r four treatment sessions in 2-3 days). Subjects were instructed postoperative week, and subjects were
24/712 Physical Therapy /Volume 74, Number 8/August 1994

4. achieved a maximum height of 30.48
cm (12 in).
Subjects in the P group initiated
R
closed-chain exercises on a 20.32-cm
(8-in) step. Subjects began with three
sets of 10 repetitions and progressed
until they could do three sets of 15
repetitions without difficulty. This
progression usually occurred within 1
week of rehabilitation in the water.
Between the second and third weeks,
subjects were advanced to a 40.64-cm
(16-in) step in chest-deep water and
the progression format was repeated.
Between the fourth and eighth weeks,
subjects used the 40.64-cm step in
waist-deep water to reduce the force
of buoyancy on body weight, thereby
increasing resistance. Exercises in
waist-deep water progressed in the
same manner. If subjects were able to
perform three sets of 15 repetitions
on the 40.64-cm step in waist-deep
water without difficulty, they were
positioned on a 40.64-cm step in
thigh-deep water for maximal resis-
tance and the sequencing format was
repeated.
The next group of exercises consisted
of standing hip flexion, extension,
abduction, adduction, and knee flex-
ion strengthening. The TR group
performed these exercises using pul-
Figure I. Pedalling device used by subjects in the water group. leys that contained a stack of 4.5-kg
(10-lb) plates. Subjects initiated each
out of the brace by the 6th postopera- with the same exercises, but used a exercise with a weight they could lift
tive week. pedalling device underwater (Fig. 1) comfortably for three sets of 10 repe-
instead of a stationary bicycle. titions and progressed until they
Rehabliltation Programs could perform three sets of 15 repeti-
Subjects in the TR group initiated tions without difficulty. Another 4.5-kg
During the second through the eighth closed-chain exercises on a 5.08-cm plate was then added, and the exer-
postope~ztive weeks, the TR group (2-in) step. Three sets of 10 repeti- cise was repeated with three sets of
performed a land rehabilitation pro- tions were performed, progressing to 10 repetitions.
gram and the P group performed a
R three sets of 15 repetitions. When
similar program in the water (Tab. 1). subjects could perform three sets of Hip strengthening and knee flexion
Both programs were performed three 15 repetitions comfortably at a given exercises were done using a Hydro-
times per week in the same sequence. height, the height was increased by tone exercise boot* (Fig. 2). Exercises
5.08 cm and they started with three consisted of three sets of 10 repeti-
Subjects in the TR group warmed up sets of 10 repetitions again. Subjects tions for hip flexion-extension,
with 10 minutes of stationary cycling, usually advanced every two or three abduction-adduction, and knee flex-
followed by 10 minutes of gait train- sessions and continued the same ion. Because this study did not intend
ing (alternating forward and backward exercise progression while the height to quantify the amount of resistance
walking) and 5 minutes of passive of the step was increased in incre- in the water or to increase the surface
stretching. The P group warmed up
R ments of 5.08 cm. Subjects usually area of the Hydrotone boot, subjects
were instructed to move their in-
volved legs through the water as fast
'Hydrotone International Inc, 3535 NW 58th St, Ste 1000, Oklahoma City, OK 73112. as they could. As symptoms decreased
Physical Therapy /Volume 74, Number 8/August 1994

5. ware (version 5.1)* were used to
calculate and record peak torque (in
foot-pounds), and gravity-corrected
measurements were obtained. Accord-
ing to the manufacturer, the dyna-
mometer's accuracy is self-calibrated
through the computer software pack-
age. One tester, who was blind to
group assignment, performed all the
testing.
During the testing session, subjects
were positioned with their hips in 80
to 90 degrees of flexion. The hips and
tested limb were stabilized with Vel-
cro@ straps across the pelvis and
over the thigh. Subjects were in-
structed to grasp the handrails during
the test. The axis of rotation of the
dynamometer was aligned with that of
the knee, and the lever arm pad was
placed 7.62 cm (3 in) below the tibial
tubercle. Subjects were allowed a
short period of familiarization at each
speed.
Isometric testing consisted of three
maximal 5-second repetitions with the
knee flexed 85 degrees to measure
knee extension torque and three
maximal 5-second repetitions with the
knee flexed 60 degrees to measure
knee flexion torque. Subjects were
given a 30-second rest period be-
Flgure 2. Hydrotone resistance boot used by subjects in the water group. tween repetitions. The highest torque
value was recorded.
and muscle performance improved, tibia on the femur was measured (in
subjects increased the speed and millimeters) during 6.8-kg (15-lb) and Isokinetic testing consisted of three
created more resistance. 9.1-kg (20-lb) Lachman tests. Greater separate contractions at 90°/s with a
forces were not used in fear of over- 30-second rest period between repeti-
Data Collection stressing the graft during this critical tions. Isokinetic extension was tested
period of graft healing. The testers from 80 to 40 degrees of knee flex-
Arthrometric measurements.Joint maintained 100% agreement, within ion, and isokinetic flexion was tested
laxity was measured preoperatively 0.5 mm, both with a prior reliability from 0 to 70 degrees of knee flexion.
and at 8 weeks following surgery. study and throughout this study. Isohnetic extension was done sepa-
Measurements were made by one of rately from isokinetic flexion to pre-
two physical therapists (BJT and JC) Muscle performance vent possible shearing during changes
using a KT-1000 knee arthrometer.' measurements. Isometric and isoki- in direction. The maximum peak
This device has the highest diagnostic netic peak knee torques were mea- torque for the three repetitions was
accuracy of five different arthrometric sured at the end of the eighth week recorded for each of the four tests. AU
de~ices.~6 Anterior drawer testing was of rehabilitation and compared be- subjects were tested in the same
performed with the knee flexed 30 tween groups. An electromechanical order.
degrees. Anterior displacement of the dynamometer$ and LIDO@AC+ soft-
Passlve range of motion
measurements. Passive range of
+Medrnetric,San Diego. CA. motion (PROM) measurements for
knee flexion and extension were
$Loredan Biomedical Inc, 2121-B 2nd St, Ste 107, Davis, C 95616.
A
taken by one of the two physical ther-
"elcro U A Inc, 406 Brown Ave, Manchester, NH 03108.
S apists using a standard plastic goni-
26/714 Physical Therapy/Volume 74, Number 8/August 1994

6. -
Table 2. Results o Analysis o Variance o Dzferences in Joint Laxity Measurements
Source
f
df
f
During a 6.8-kg (15-lb) Lachmun Test
SS
f
MS F P
The ROM measurements for weeks 2,
4, 6, and 8 were analyzed using a
two-way ANOVA (groups X weeks) for
repeated measures. A Tukey's pair-
wise comparison post hoc test for
significance was used for within-
group comparisons, and a Bonferroni
Between subjects pair-wise comparison was used for
between-group comparisons.
Groups (A) 1 21 .OO 21 .OO 3.43 ,082
Error 17 104.08 6.12
Girth measurements were calculated
Within subjects
from measurements of girth at mid-
Weeks (B) 1 50.84 50.84 8.39 .01 patella and 15.24 cm above mid-
AxB 1 0.003 0.003 0.00 ,984 patella. Mean differences were com-
Error 17 103.05 6.06 pared at 2, 4, 6, and 8 weeks using
tests identical to those undertaken for
ROM. The alpha level of significance
ometer (17.78 cm [7 in] long with a 100% agreement, within 0.636 cm (Y4 was set at .05.
360" scale and 1" increments). The in), both with a prior reliability study
testers maintained 100% agreement, and throughout this study. Results
within 5 degrees, both with a prior
reliability study and throughout this Functional questlonnalre.A func- Results of the ANOVAs for joint laxity
study. tional questionnaire was administered measurements, presented in Tables 2
at the end of the eighth postoperative and 3, showed no significant differ-
Passive range of motion was mea- week. The questionnaire consisted of ence between groups (F=3.43, 4.04;
sured at the beginning of each treat- a Lysholm scale,27 which quantifies df=l,l;P=.08, .06), indicating that
ment session at 2, 4, 6, and 8 weeks the functional use o the knee joint
f neither program induced more laxity
postoperatively. Subjects were al- using a scale of 0 to 100. This rating than the other. A significant effect for
lowed a 3-minute warm-up, which system is a self-report of the subject's time did exist at both the 6.8-kg
consistell of self-stretching within perceived ability of activities such as (F=8.39, df=l, P=.01) and 9.1-kg
their available ROM. Both measure- walking, stair climbing, and squatting forces (F=24.0, df= 1,P=.0001), indi-
ments were taken with subjects posi- and is an accepted method of evaluat- cating that both groups had sign&-
tioned supine. Knee extension mea- ing functional impairment.27,28 Higher cantly less joint laxity at 8 weeks after
surements were taken with a towel scores indicated better functional use surgery compared with before
roll under the heel of the involved with fewer symptoms. surgery.
extremity. Knee flexion measurements
were taken with the hip maintained at Data Management and Analysis Comparison of quadriceps femoris
90 degrees of flexion, while the heel and hamstring muscle isometric and
was moved toward the buttocks. End- Side-to-side differences in joint laxity isokinetic peak torque percentages
range was determined by applying measurements were calculated and (Tab. 4) between groups revealed no
overpressure until firm resistance was used to compare the values between significant differences for isometric
met. The maximum value o threef groups prior to surgery and 8 weeks knee flexion, isometric knee exten-
measurements was recorded. following surgery. Mean differences sion, and isokinetic knee extension
were compared using an analysis of peak torque percentages. The isoki-
Girth measurements. Girth mea- variance (ANOVA). A Tukey's pair-wise netic knee flexion peak torque per-
surements were taken by one of the comparison was used for within- centage, however, was significantly
two physical therapists during the group comparisons, and a Bonferroni higher for the TR group @=96.4,
preoperative visit and at 2, 4, 6, and 8 pair-wise comparison was used for SD=13.5) than for the PR group
weeks following surgery. Measure- between-group comparisons. @= 81.7, SD=11.1) (P=.01).
ments were taken at the mid-patella
level and 15.24 cm (6 in) above the Measurements of isometric and isoki- Passive range of motion measure-
mid-patella using a standard tape netic peak torque for the quadriceps ments were recorded at weeks 2,4, 6,
measure (increments of 0.3175 cm femoris and hamstring muscles were and 8. Table 5 shows that there were
[?h with subjects positioned su-
in]) normalized to the values of the unin- no significant differences between
pine with their thigh musculature volved contralateral musculature and groups at each measurement period
relaxed. 'These measurement locations expressed as a percentage. The mean (F=0.38, df=l, P=.546). As expected,
were used to document changes in peak torque percentage and the mean there was a significant effect for time
knee joint e h s i o n and thigh muscu- Lysholm score were compared be- (F= 116.49,df=3, P=.0001), implying
lar atrophy. The testers maintained tween groups using a Student's t test. that knee joint PROM for both groups
Physical 'rherapy/Volume 74, Number

7. -
Table 3. Results of Analysis of Variance of Differences in Joint Laxity Measurements
During a 9.1-kg (20-lb)Lachrnan Test
Source df SS MS F P
between the baseline measurement
and the second postoperative week,
but no difference existed between
groups. Mean Lysholrn scores were
significantly higher in the P group
R
@=92.2, SD=4.31) than in the TR
group @=82.4, SD=12.36) (P=.03)
Between subjects
Groups (A)
Error 17 156.20
Lysholm scale measurements showed
Within subjects
that the P group scored significantly
R
Weeks (B) 1 123.73 higher than the TR group at 8 weeks,
A x B 1 0.25 indicating that this group had fewer
Error 17 87.64 problems with activities o daily living.
f
Increased pain, based on the subjects'
self-report, and knee swelling during
improved over the 8 weeks. At 2 Girth measurements taken at mid- activities of daily living were primarily
weeks following surgery, the first patella and 15.24 cm above mid- responsible for lower scores in the
PROM measurement showed that patella were compared between T group. The results of the laxity
R
both groups had an average of 117 knees to determine mean differences and girth measurements may offer
degrees of knee PROM. Both groups (Tab. 6). Between-group analysis possible reasons why the P group
R
showed progressive increments over showed that the P group had less
R had higher Lysholm scores.
time, averaging 20 degrees between girth than the TR group for each mid-
weeks 2 and 4, 8 degrees between patella measurement, but the differ- A 8 weeks following surgery, both
t
weeks 4 and 6, and 4 more degrees ence was significant only at 8 weeks. groups had less than 3 mm of differ-
between weeks 6 and 8. Mean knee No significant difference between ence in joint laxity between the in-
PROM for both groups at the end of groups was noted (F=2.09, df= 1, volved and uninvolved knees for both
the 8-week program was 150 degrees. P=.l66). A time effect was shown the 6.8- and 9.1-kg Lachman tests.
Post hoc analysis revealed that gains (F=23.45, df=4, P=.0001), as both Neither program induced knee joint
in PROM were significant for both groups had a significant increase in laxity, as a laxity difference of 5 3 mm
groups only during the first 6 weeks. girth at mid-patella between the base- is considered normal.29 Although
No significant differences were noted line measurement and the second between-group comparisons revealed
between groups. There was no signifi- postoperative week. Additionally, both no significant difference, the within-
-
cant groupx time interaction, indicat- groups showed a significant decrease group means at the end of 8 weeks
ing that change in PROM over time in girth at mid-patella after the second indicated that the T group had
R
was not dependent on assignment. week, but only until week 4. At 15.54 greater than 1.5 mm more laxity for
cm above mid-patella, both groups both tests than the P group. The
R
had significant decreases in girth inability to detect a significant differ-
ence between groups may have been
due to insufficient sample size. This
result may be due to the increased
stresses on the knee joint during
Table 4. Means and Standard Deviations for Group Peak Torque Recovery at the rehabilitation on land with
Eighth Postoperative Week (Percentage of Nonoperative Limb's Peak Torque)
in water.l5 Increased knee joint laxity
in the surgical knee at 8 weeks could
lsometrlc Peak lsoklnetlc Peak have resulted in increased knee joint
Torque Percentage Torque Percentage effusion, which may have led to the
(07s) (90°1s) lower Lysholm scores.
Group % SD % SD
Girth measurements taken at 15.24 kg-
above mid-patella showed no signs-
Traditional rehabilitation (n=9)
cant difference between groups for
Flexion 85.1 9.1 96.4 13.5
atrophy of the thigh musculature.
Extension 43.1 11.6 56.1
9.2 Within-group comparison, however,
Pool rehabilitation (n=10) revealed that both groups followed
Flexion 83.7 10.6 81.7 1l.l the same significant changes from the
Extension 42.8 12.7 50.6 18.1 presurgical measurement until the
eighth postoperative week. Both
Physical Therapy /Volume 74, Number 8/August 1994

8. in greater circumferential
measurements.
Table 5. Results of Analysis of Variance of Dgerences Between Groups in Recovey
of Range of Motion
Girth measurements taken at mid-
patella showed that the girth for the
Source df SS MS F P PR group was consistently less at each
time period, but these differences
Between subjects
were significant only at 8 weeks. As
discussed earlier, the increased ginh
Groups (A) 1 132.61 132.61 0.38 ,546
in the TR group may have been
Error 18 6287.63 349.31
caused by the joint effusion resulting
Within subjects
from greater stress on the joint dur-
Weeks (B) 3 13277.84 4425.95 1 16.49 .0001 ing land exercises compared with
AXB 3 48.24 16.08 0.42 ,737 water exercises. This increased joint
Error 54 2051.66 37.99 effusion may have led to lower Ly-
sholm scores.
groups experienced the greatest Thigh girth began to increase after Within-group comparison reveals that
change between the presurgical mea- the fourth postoperative week, and mid-patella ginh measurements
surement and the second postopera- the involved extremity was within changed similarly for both groups;
tive week, with the greatest decrease 1.90 cm (0.75 in) of the contralateral that is, measurements at this location
in girth occurring at the fourth post- extremity by the eighth postoperative were inversely related to the mea-
operative week. Thigh musculature week for both groups. Increases in surements taken at 15.24 kg above
atrophy is commonly observed during thigh girth at this time may be attrib- mid-patella. The greatest increase in
the acutt: postsurgical period due to uted to several factors. As postopera- girth was noted between the presurgi-
muscle inhibition that takes place tive joint effusion and pain decrease cal measurement and the second
from the increased joint effusion and while ROM increases, the thigh mus- postoperative week, suggesting the
-
increased pain. DeAndrade et a 3 1O culature can b e exercised through a increased joint effusion that typically
have shc~wn that with increased knee greater ROM. As exercises are per- occurs following surgery. These re-
joint effusion, there is less muscle formed more vigorously, muscle sults indicate that as joint effusion
output as measured by electromyo- tissue begins to hypertrophy, resulting decreases, muscle girth increases,
graphic activity. with the transition occurring around 4
to 6 weeks following surgery.
Between-group comparison for peak
torque percentages (PTPs) showed
Table 6. Results of Analysis of Variance of Dzffwences Between Groupsfor Girth that the T group had a significantly
R
Measurenzents at Mid-patella and 40.62cm (6 in) Above Mid-patella higher PTP for the hamstring muscles
at 90°/s, indicating that the traditional
Source df SS MS F P rehabilitation approach was more
effective than the pool rehabilitation
approach for strengthening the ham-
Mid-patella string muscles. This result may have
Between subjects occurred for two reasons. First, resis-
Groups (A) tance in the water was partially deter-
Error mined by the speed of limb move-
Within sl~bjects ment, which was controlled by each
Weeks (B) subject.16 Subject effort can be affected
A x m
B by pain and motivation. Therefore,
40.64 cm above mid-patella subjects may not have generated
Betweeri subjects
enough resistance to facilitate maxi-
mal strengthening. Hamstring muscle
Groups (A) 1 0.006 0.006 0.01 ,933
exercises in the TR group were done
Error 17 15.53 0.80
using weights, so resistance was not
Within S L J ~ ~ ~ C ~ S
self-paced. Second, there is a differ-
Weeks (B) ence in the type of muscle contrac-
AXB tion that occurs o n land. Empirical
Error evidence suggests that an eccentric
muscle contraction is important for
Physical Therapy /Volume 74, Number 8/August 1994

9. restoring muscle perf0rmance.3~This tions resulted in donor site pain (the step-ups, and the land pulleys ap-
type of contraction is more likely to anatomical site at which the central peared to be most beneficial for ham-
occur on land than in water due to third o the patellar tendon was surgi-
f string muscle and hip strengthening.
increased gravitational forces. cally removed for use as an au- Isolated quadriceps femoris muscle
tograft) in some subjects in both contractions in a safe range using
In both groups, there was equal effec- groups, which may have altered the open-chain exercises may have bene-
tiveness in restoring quadriceps femo- remaining tests. Anterior knee pain is fited both groups.
ris muscle strength. These results also common in the early phases of ACL
showed that greater joint effusion in rehabilitation if a patellar tendon Patients using a pool for rehabilitation
the TR group did not significantly autograft is used. Testing isometrically are likely to tolerate an even more
affect peak torque muscle perfor- and at slow speeds increases the joint aggressive rehabilitation program than
mance. A possible reason for this reaction forces around the patella, but that presented in this study. In this
finding is that all subjects were tested usually is a better indicator of study, however, exercises in both
in the range of 85 to 40 degrees of strength. Although strength testing in groups had to be carefully matched to
knee flexion, rather than at the end- this study provided adequate graft ensure that the main effect between
range where joint effusion has been protection, testing at faster speeds first rehabilitation programs was due to
shown to s e c t muscle perfonnance.30 and slower speeds at the end of the the environment. The PR group could
testing session might have resulted in have performed more advanced exer-
The mean PTPs for both groups are better PTP scores. The testing proce- cises, but varying the exercises would
similar to those reported for other dure in this study did not take these have made interpretation of results
subjects with ACL reconstructions.5 factors into account because at the unclear because differences between
Other studies,7,8 however, have dem- time the study was proposed, no groups could have then been attrib-
onstrated higher peak torque values. published research had incorporated uted to the environment, exercises, or
Two possible explanations for lower isokinetic testing at 8 weeks, using interaction between the two.
PTPs in this study are the type of only subjects with patellar tendon
quadriceps femoris muscle strength- autografts.
ening and methodological factors.
Clinical lmpllcatlons Although traditional exercises have
Type of Quadriceps Femoris been the treatment choice of most
Muscle Strengthenlng Although a primary goal in the reha- clinicians, the results of this study
bilitation of patients with ACL recon- suggest that a rehabilitation program
The method of quadriceps femoris structions is the restoration of quadri- for patients with intra-articular ACL
muscle strengthening in both groups ceps femoris muscle performance, the reconstructions performed in a pool
focused on closed-chain exercises, means of achieving this goal must is more effective in reducing joint
which may not have provided enough avoid overstressing the graft and in- effusion and facilitating recovery of
isolated stimulus to the quadriceps creasing joint ehsion. Addttionally, to lower-extremity function as indicated
femoris muscle to facilitate maximum expedite recovery, patients must toler- by Lysholm scores. The results also
strength gains. Previous studies,7.8 ate the rehabilitation program. Some suggest that rehabilitation in water is
which demonstrated higher strength patients find postoperative exercises equally effective as on land for restor-
gains, applied neuromuscular electri- too uncomfortable because of age, ing knee ROM and quadriceps femo-
cal stimulation during open-chain low presurgical activity level, o r low ris muscle strength, but not as effec-
knee extension exercises. Both pain tolerance, and progression dur- tive in restoring hamstring muscle
groups in this study may have bene- ing the early phases of rehabilitation strength. Clinicians who wish to allow
fited from isolated knee extension is limited. maximal weight bearing may find the
exercises through a limited ROM (90" adjunct of aquatic exercises useful.
to 40" of knee flexion to ensure graft Exercises in water may make the total Future studies should analyze the
protection), as recent research find- rehabilitation program more tolera- effectiveness of a program that com-
ings indicate that closed-chain exer- ble. Although a complete aquatic bines traditional and water exercises,
cises alone may not b e enough to exercise program may be unneces- using larger sample sizes and a
facilitate maximum muscle perfor- sary, augmenting a land program with longer follow-up period.
mance as measured by isokinetic pool exercises may permit loading
dynamometry.32 the joint to a greater degree. For Acknowledgments
patients who are unable to tolerate
Methodological Factors traditional exercises on land, water We thank Lynn Snyder-Mackler, ScD,
can be used to facilitate progression PT, for assisting with preparation of
Changing the methodology may have to more aggressive exercises. In this this manuscript; Roberto Infante, PT,
resulted in higher mean PTPs. Per- study, a water environment was most and the staff at Resurgeons Ortho-
forming three 5-second isometric beneficial for facilitating closed-chain paedics for their assistance with data
quadriceps femoris muscle contrac- exercises, such as gait training and
Physical Therapy/Volume 74, Number 8/August 1994

10. collection; and Piedmont Hospital for tions Springfield, Ill: Charles C Thomas, Pub- loskeletal conditioning.] Bum Care Rehabil.
use of their facilities. lisher; 1955. 1988;9:203-206.
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Physical 'Therapy/Volume 74, Number B/August 1994