Comparison of Quadriceps Exercise Modalities on Pain, Muscle Strength, Function, and Balance in Bilateral Knee Osteoarthritis

Abstract

Introduction: This study aimed to investigate the effects of various exercises on quadriceps femoris muscle and on pain, strength, function, and balance in female patients with bilateral knee osteoarthritis (OA).
Methods: Forty-five female patients aged 40-65 years were diagnosed with bilateral knee OA according to the American College of Rheumatology criteria and randomized into three groups. The pain and function of the patients in each group were evaluated by the visual analog scale and Western Ontario and McMaster Universities Osteoarthritis Index questionnaires. Muscle strength and endurance were measured with the Isokinetic System Cybex 350, and balance was evaluated with Biodex Balance System SD. Group 1 performed a home-based isometric exercise program, while groups 2 and 3 performed strength and endurance exercises, for 4 days per week for 6 weeks.
Results: At week 6, only the activity pain scores decreased in group 1, whereas rest, night, and activity pain scores decreased significantly in groups 2 and 3 (p

Full text

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Original Investigation
©Copyright 2022 by the University of Health Sciences Turkey, İstanbul Training and Research Hospital/İstanbul Medical Journal published by Galenos Publishing House.
İstanbul Med J 2022; 23(1): 6-11
Received: 05.08.2021
Accepted: 03.01.2022
Address for Correspondence:
Dilek Çokar MD, İstanbul University, İstanbul Faculty of Medicine, Department of Sports
Medicine, İstanbul, Turkey
Phone:
+90 534 307 27 52
E-mail:
cokardilek@gmail.com
ORCID ID:
orcid.org/0000-0003-4681-1987
Cite this article as: Çokar D, Yıldız S, Şahinkaya T, Dinçer Ş, Gözübüyük ÖB, Özgönenel L. Comparison
of Quadriceps Exercise Modalities on Pain, Muscle Strength, Function, and Balance in Bilateral Knee
Osteoarthritis. İstanbul Med J 2022; 23(1): 6-11.
Introduction
Osteoarthritis (OA) is a progressive state of weight-bearing joints such as
the knee and is common in geriatric patients (1). Knee OA is commonly
associated with quadriceps femoris muscle weakness, functional
impairment, reduced quality of life, and increased morbidity and
mortality (2). Age-related sarcopenia and reduction in muscular strength
result in the reduction of activities of daily living and mobility of the
patients and increases falling risk. It also reduces proprioception of the
knee joint, which further contributes to this process. OA has been shown
to affect muscle strength and mechanoreceptors at the knee joint, thus
increasing the risk of balance problems in patients (3,4).
The initial treatment for OA includes medications, lifestyle modification,
and rehabilitation. This treatment aims to manage pain, preserve
and improve joint functioning, provide functional independence,
and improve quality of life (2,5-7). Exercise treatment is one of the
critical components of the rehabilitation program, as emphasized
by numerous studies (5,6,8). However, the target muscle group for an
exercise program, type and intensity, and outcomes of such programs
on patients’ symptomatology have been debated. Most commonly, the
quadriceps muscle group was the target for a specific exercise program,
but a broader lower extremity program, as well as aerobic programs,
has been studied. A specific exercise program targeting the quadriceps
muscle group was most effective in reducing patients’ symptoms (9).
There is no definite consensus on the type, dose, and effect of exercise
for the quadriceps femoris muscle on parameters such as pain, physical
function, strength, and balance in OA (5,9).
This study aimed to investigate the effects of different types of
quadriceps femoris muscle exercises with varying intensities on pain,
Dilek Çokar1, Safinaz Yıldız1, Türker Şahinkaya1, Şensu Dinçer1, Ömer Batın Gözübüyük2,
Levent Özgönenel3
1İstanbul University, İstanbul Faculty of Medicine, Department of Sports Medicine, İstanbul, Turkey
2MP Sports Physicians, Melbourne, Australia
3Demiroğlu Bilim University Faculty of Medicine, Department of Physical Medicine and Rehabilitation, İstanbul, Turkey
Introduction: This study aimed to investigate the effects of various exercises on quadriceps femoris muscle and on pain, strength,
function, and balance in female patients with bilateral knee osteoarthritis (OA).
Methods: Forty-five female patients aged 40-65 years were diagnosed with bilateral knee OA according to the American College of
Rheumatology criteria and randomized into three groups. The pain and function of the patients in each group were evaluated by
the visual analog scale and Western Ontario and McMaster Universities Osteoarthritis Index questionnaires. Muscle strength and
endurance were measured with the Isokinetic System Cybex 350, and balance was evaluated with Biodex Balance System SD. Group 1
performed a home-based isometric exercise program, while groups 2 and 3 performed strength and endurance exercises, for 4 days
per week for 6 weeks.
Results: At week 6, only the activity pain scores decreased in group 1, whereas rest, night, and activity pain scores decreased
significantly in groups 2 and 3 (p<0.001, p<0.01 and p<0.001, respectively). Significant improvements in physical functions were
found in each group (p<0.001). The isokinetic muscle strength for knee extensors increased significantly in groups 2 and 3 (p<0.001,
p<0.01, respectively). The balance scores of groups 2 and 3 were improved at certain positions (p<0.001, p<0.05, respectively).
Conclusion: Isometric exercises are widely used in the treatment of patients with knee OA. However, high-intensity isotonic exercises
is recommended because of the shorter time of intervention for improving muscle strength, slowing the progression of the disease,
and reducing the future risk of falling by improving balance.
Keywords: Osteoarthritis, exercise, pain, function, balance
ABSTRACT
Comparison of Quadriceps Exercise Modalities on Pain,
Muscle Strength, Function, and Balance in Bilateral Knee
Osteoarthritis
DO I: 10.4274/imj.galenos.2022.69009

Çokar et al. Quadriceps Exercises in Patients with Gonarthrosis
7
muscle strength, physical function, and balance of female patients with
bilateral knee OA.
Methods
The study recruited patients with newly diagnosed OA of the knee.
Selection criteria were based on the clinical and radiological criteria
defined by the American College of Rheumatology for knee OA. In
addition, patients at grade 2 and 3, according to the Kellgren-Lawrence
Classification, were included, and these patients in each group had
homogeneous characteristics. Female patients aged 40-65 years with
a diagnosis of bilateral knee OA who were admitted to the outpatient
physical medicine and rehabilitation clinics of İstanbul University
Faculty of Medicine and Şişli Florence Nightingale Hospital between
March 2016 and December 2016 were included in the study.
The Clinical Research Ethics Committee of İstanbul University, İstanbul
Faculty of Medicine (approval number: 2016-249, date: 29.02.2016)
approved the study. This study was supported by İstanbul University
Scientific Research Projects Unit (project no: 22047).
Patients who had a history of knee or hip surgery, who received an intra-
articular injection in the previous 3 months, whose knee flexion range
was <100° or with an extension loss >10°, patients with a neurological
disorder that affects lower limb musculature, or patients with an
inflammatory rheumatologic condition were excluded.
In total, 46 patients volunteered for the study and signed the informed
consent forms. One patient withdrew from the study because of
family commitments. The remaining 45 patients were divided into
three groups according to the order of admittance to the clinic.
Patients were assessed with the same measures before and after the
6-week treatment. The assessments included knee range of motion
measurement, visual analog scale (VAS), Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC), knee strength and endurance
assessment using an isokinetic dynamometer, and balance assessment
using a Biodex Balance System.
Patient report forms: Each patient report form included demographic
information including age, weight, height, history and family
background, patient occupation, knee range of motion values, and
progress charts for each session.
Assessment of pain levels: VAS was used to assess the patients’ level of
pain. Three measures were noted to assess pain at rest, with physical
activity, and at night. Patients were provided with a 10 cm long horizontal
scale, and they were asked to put a mark on this scale to represent their
pain level. The scale was described to patients as “0” representing a state
of no pain at all and “10” representing an unbearable pain. The distance
was then measured and noted.
WOMAC index: This index is widely used by clinicians to assess pain,
stiffness levels, and functional status of patients with OA. The index
consists of 24 questions and three main sections. Pain is assessed with
5, stiffness with 2, and physical functioning with 17 questions in these
sections. Higher scores in the WOMAC index represent increased pain
and stiffness and worsened physical functioning (10,11).
Measurement of muscular strength and endurance: Muscular
strength and endurance of the knee flexor and extensor muscle group
were assessed with a Cybex 350® isokinetic dynamometer system. The
patients warmed up with a stationary bike for 7 min at 65 rpm with an
intensity of 2/10. The muscular strength of the knee was measured for
five repetitions after a trial of three maximal knee flexion and extension
movements at a low angular velocity (60°/s). The average peak torque,
peak torque/body weight, total work done, and total work/body weight
values of the five repetitions were noted. The same exercise specialist
performed the measurements throughout the study and provided
patients verbal motivation during the tests. Endurance was then
measured using a high angular velocity (180°/s) for 15 repetitions after
a trial of five repetitions. The average peak torque, peak torque/body
weight, total work done, and total work/body weight values of the 15
repetitions noted. Both extremities were measured (12).
Measurement of balance: The static balance of the patients was
measured using the Biodex Balance System®, which was regularly
calibrated each year. The test platform was set to the static mode. The
patients were asked to maintain a balanced stance position at these
settings: i) eyes open, knees are at full extension; ii) eyes closed, knees
at full extension; iii) eyes open, knees bent by approximately 30°; and
iv) eyes closed, knees bent by approximately 30°. The anteroposterior
index, mediolateral index, and overall index were assessed using the
internal post-processing algorithm of the device. Each position was
tested three times, and an average value representing each index was
noted (13).
Treatment Groups
1. Isometric exercise group (group 1)
Isometric knee exercises were prescribed as a home-based exercise
program. The patients were asked to perform maximal isometric knee
extension exercise for 5 s and repeat this 10 times while sitting with
their knees extended. A towel was placed under the exercising knee
to facilitate the knee extension at this position. Exercise intensity
was assessed via the OMNI 0-10 scale (0 as “extremely easy” to 10 as
“extremely hard”) (14). When perceived exertion was reduced to ≤5 on
a 10-point scale, they were asked to perform 20 repetitions instead of
10. Patients performed these exercises four times per week within 6
weeks. Each patient was followed up via phone calls, which reviewed
the technique of exercise, total exercise duration and frequency, and
rate of perceived exertion.
2. Strength exercise group (group 2)
Patients were allocated into a high-intensity low-repetition isotonic
strength exercise program supervised by a physiotherapist for 6 weeks
(Table 1). Patients performed these exercises four times per week. The
intensity was determined by the 1-RM method, and patients performed
the exercise for five repetitions at an intensity of 80% of 1-RM during the
first 3 weeks and five repetitions at 90% during the second 3 weeks (15).
Sandbags were used to achieve the desired intensity. There were no pain
flare-ups during or after the high-intensity sessions.

İstanbul Med J 2022; 23(1): 6-11
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3. Endurance exercise group (group 3)
Patients were allocated into a low-intensity high-repetition isotonic
endurance exercise program (Table 1). Patients performed these exercises
four times per week. group 3 performed the same exercise as group 2,
with a different intensity and repetition. The patients performed the
exercise for 20 repetitions at an intensity of 40% of 1-RM during the first
3 weeks and for 20 repetitions at 50% during the second 3 weeks (15).
Sandbags were used to achieve the desired intensity.
Statistical Analysis
Statistical analysis of the data was performed with SPSS version 21.0®
(Statistical Package for Social Sciences). Data normality was assessed
using the Shapiro-Wilk test, which showed a normal distribution.
Therefore, parametric tests were used for further analysis. P<0.05
was set as a significance threshold for all values. A One-Way analysis
of variance test was used to assess between-group differences, and
Bonferroni correction was applied. Paired sample t-test was used to
assess within-group differences before and after treatment. A mean
difference was also calculated before and after treatments.
Results
The average age, height, and weight of the groups were comparable
(Table 2). Activity pain reduced significantly after the exercise therapy
in group 1 (p<0.001). Activity pain (p<0.001), resting pain (p<0.01), and
night pain (p<0.001) reduced significantly in groups 2 and 3 (Table 3).
Average pain, stiffness, and physical functioning values of the WOMAC
index reduced significantly in group 1 (p<0.05, p<0.01, and p<0.001,
respectively) and in group 2 (p<0.001, p<0.01, and p<0.001 respectively).
The average pain (p<0.001) and physical function (p<0.001) values of
the WOMAC index reduced significantly in group 3, whereas the stiffness
value did not change (Table 3).
In group 1, isokinetic muscle strength and endurance measures (peak
torque, peak torque/body weight, total work done, and total work/body
weight) were not different from baseline in the knee extensor muscle
group of both extremities, whereas the peak torque of the flexor muscle
group of both knees (p<0.05) and the peak torque/body weight of the
left knee (p<0.05) showed significant changes (Table 4). In group 2, all
measures from the isokinetic assessment showed remarkable increases
in both extensor and flexor muscle group in both knees (Table 4, 5). In
group 3, extensor muscles had increased maximal strength, such as peak
torque [right knee (p<0.05), left knee (p<0.01)] and peak torque/body
weight (p<0.01), in both knees (Table 4). Moreover, the peak torque,
peak torque/body weight, total work done, and total work/body weight
showed remarkable changes for the flexor muscle group of the left knee
(p<0.05) (Table 5).
Balance assessment of group 1 did not result in significant changes
in either of the scores. Group 2 showed significant improvements in
“eyes open, knees in extension” (p<0.001), “eyes open, knees in flexion”
(p<0.05), and “eyes closed, knees in flexion” conditions (p<0.001).
However, no significant changes were observed in the “eyes closed,
knees extended” condition. In group 3, only “eyes closed, knees in
flexion” and “eyes open, knees in flexion” balance conditions showed
improvements (p<0.05) (Table 6).
Discussion
The management of knee OA involves medical treatment, lifestyle
modification, and rehabilitation. Exercise is one of the critical
components of the rehabilitation program (5,6,8). The effectiveness of
specific exercises for the quadriceps femoris muscle is widely accepted.
However, the type, intensity, duration, and frequency of the planned
exercise are still not established. Thus, this study investigated the
effects of different types and intensities on strength, pain, function, and
balance.
Our results revealed that the VAS score only improved for “pain during
activity” in group 1, whereas all types of pain improved in groups 2 and
3. These results are consistent with the literature. Additionally, all three
groups have significantly improved pain, stiffness, and daily physical
functioning scores in the WOMAC index compared with the pretreatment
values. These results also support the literature data (6,9,16-21).
Fransen et al. (18) compared the effect of knee flexor and extensor
muscle strength exercises in reducing pain and increasing physical
function in patients with knee OA. They found that the increase in
knee extensor muscle strength is more related to improvement in both
parameters than to flexor muscle strength. Moreover, they reported that
exercise treatment is more effective in decreasing pain than analgesic
medication. They also noted that exercise therapy was more effective
than analgesic drugs for reducing pain. Our study revealed that pain
decreased and physical function improved in all types of muscle
strengthening that were applied to the extensor muscle group. Juhl et al.
(9) examined the effect of exercise type and dose on pain and disabilities
in knee OS in a systematic review and meta-regression analysis of
randomized controlled trials. They suggested that an optimal exercise
program for knee OA is performed at least three times a week. Pelletier
et al. (19) also reported that an 8-week exercise program consisting of
Table 1. Applied exercises
Exercises for group 1 Exercises for groups 2 and 3
- Hamstring stretching - Hamstring stretching
- Quadriceps femoris stretching - Quadriceps femoris stretching
- Supine straight leg raise - Supine straight leg raise
- Supine knee press - Supine short-arc knee extension
- Supine ball squeeze in between
legs - Knee extension while sitting
- Straight leg raise in side-lying - Short-arc knee extension while sitting
Table 2. Demographic data
Parameters Group 1
(mean ± SD)
Group 2
(mean ± SD)
Group 3
(mean ± SD) p
Age (year) 48.20±7.5 53.6±9.1 52.4±6.7 0.121
Height (m) 1.63±0.5 1.59±0.7 1.60±0.5 0.148
Body weight (kg) 82.6±13.9 78.0±10.3 82.7±5.9 0.383
Body weight (after
6 weeks) (kg) 82.2±14.2 78.3±10.7 82.5±7.06 0.515
SD: Standard deviation

Çokar et al. Quadriceps Exercises in Patients with Gonarthrosis
9
three times weekly sessions of quadriceps femoris strength exercises
(knee flexion-extension) reduced pain and improved daily functions in
patients with knee OA. In the present study, we determined the duration
and frequency of exercise as a 6-week exercise program consisting of
four sessions per week, which is consistent with the literature. At the end
of this period, we found significant improvements in pain and physical
function in all groups.
Table 4. Isokinetic assessment of knee extensor muscle group before and after exercise
Parameters
Group 1 Group 2 Group 3
BE AE BE AE BE AE
Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD
Right knee
extensors
Peak torque (N.m) 108.8±22.5 106.8±23.1 82.1±17.7 97.7±20.9*** 88.8±24.6 94.8±23.2*
Peak torque/body weight
(N.m/kg) 130.0±25.8 132.8±35.9 107.1±26.05 127.06±32.2*** 106.5±30 115.06±27.9**
Total work (N.m) 658.2±154.8 635.4±169.6 502.3±153.3 587.8±131.4*543.8±218.4 521.6±173.2
Total work/body weight
(N.m/kg) 811.2±195.6 790±229.4 661.4±220.9 765.9±202.4*649.6±240.6 631.2±203.8
Left knee
extensors
Peak torque (N.m) 104.2±18.7 106.6±22.04 87.8±21.6 101.8±20.5*** 84.06±23.7 92.8±22.6**
Peak torque/body weight
(N.m/kg) 128.4±26.1 131.8±30.8 114.1±31.09 131.4±29.9*** 100.7±26.6 112.8±28.3**
Total work (N.m) 593.7±123.1 599.7±161.4 493.9±143.3 586.8±135.8** 481.8±183.7 526.06±186.8
Total work/body weight
(N.m/kg) 729.6±149.3 739.3±198.1 646.7±214.9 759.2±193.4*575.8±197.7 635.2±210.6
BE: Before exercise, AE: after exercise, SD: standard deviation, *: p<0.05, **: p<0.01, ***: p<0.001)
Table 5. Isokinetic assessment of knee flexor muscle group before and after exercise
Parameters
Group 1 Group 2 Group 3
BE AE BE AE BE AE
Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD
Right knee
exors
Peak torque (N.m) 62.6±11.8 66.8±12.6*50.9±10.08 64.3±15.2*** 60.6±17.3 63.9±16.4
Peak torque/body weight
(N.m/kg) 76.4±13.4 83.2±18.1 67.06±16.8 83.6±22.7*** 73.2±19.5 77.6±20.6
Total work (N.m) 446.1±93.6 474.2±130.2 373.6±116.3 478.8±192.3** 407.9±121.9 441.06±137.5
Total work/body weight
(N.m/kg) 552.5±131.4 591.2±178.4 492.1±172.0 628.4±266.6** 487.9±130.7 534.9±165.4
Left knee
exors
Peak torque (N.m) 64.1±11.5 69.0±15.2*52.5±8.8 64.4±13.6*** 58.5±17.3 662±20.3*
Peak torque/body weight
(N.m/kg) 77.8±11.5 84.7±18.5*68.4±12.7 83.7±19.1*** 70.3±19.2 80.4±25.2*
Total work (N.m) 473.6±103.8 511±128.01 383.1±119.7 464.4±138.8** 406.1±134.5 477.8±175.5*
Total work/body weight
(N.m/kg) 585.0±152.7 631.2±166.6 501.7±183.3 606.6±206.6*485.7±143.1 582.6±219.01*
BE: Before exercise, AE: after exercise, SD: standard deviation, *: p<0.05, **: p<0.01, ***: p<0.001
Table 3. Comparison of VAS and WOMAC scores before and after exercise
Parameters
Group 1 Group 2 Group 3
BE AE BE AE BE AE
Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD
VAS
Rest 3.2±3.4 2.2±2.1 3.4±3.06 0.9±1.5*** 4.06±3.1 1.1±2.03***
Night 2.6±3.3 1.9±2.3 3.3±3.5 0.8±1.8** 4.1±3.1 0.8±1.4**
Activity 6.3±3.4 4.5±2.6*** 7.6±2.1 3.4±2.09*** 6.7±2.3 3.2±2.3***
WOMAC
Pain 6.7±4.5 5.4±3.6*9.4±4.3 4.5±2.5*** 9.2±4.2 4.3±2.8***
Stiffness 3.3±2.7 2.1±1.8** 3.5±2.5 1.2±1.3** 2.7±1.6 1.8±1.8
Physical function 21.9±16.5 17.4±14.3*** 23.4±12.9 12.0±5.9*** 27.5±10.8 14.8±13.7***
BE: Before exercise, AE: after exercise, SD: standard deviation, *: p<0.05, **: p<0.01, ***: p<0.001, VAS: visual analog scale, WOMAC: Western Ontario and McMaster Universities
Osteoarthritis Index

İstanbul Med J 2022; 23(1): 6-11
10
The isokinetic strength of the knee extensor muscle group in group 1 did
not show significant changes in our study. This suggests that a 6-week
home-based isometric knee exercise program does not significantly
increase muscular strength in patients with knee OA. However, this
could be an expected outcome, as the exercises were isometric, and
isometric exercises should be performed for an extensive period to
gain significant strength. In group 2, all isokinetic strength parameters
improved significantly. We believe that these improvements are mainly
due to neuronal adaptation, as 6 weeks is a relatively short duration
to observe hypertrophy to its full extent. These results regarding both
isometric and strength exercises also overlap with the physiological
mechanisms expressed in a previous study (22).
Messier et al. (21) suggested that higher-intensity exercises worsen the
knee pain, degenerate structures around the joint, increase the risk
of injury, and may increase blood pressure of patients with knee OA.
Raymond et al. (23) emphasized the positive effects of high-intensity
progressive muscle strengthening exercises on muscle strength, physical
function, depression, and quality of life in patients aged >65 years in
a systematic review of 21 randomized controlled studies. Their results
suggest that higher-intensity isotonic exercises are superior in gaining
muscular strength; however, other types and intensities of exercises
could be preferred for improving other parameters such as physical
function, depression, and life quality index. We did not encounter risk
events of high-intensity exercise in our study. Our results are consistent
with the literature finding that supports the benefits of high-intensity
isotonic exercise to strengthen knee muscles. We also showed that other
types and intensity of exercises could improve other parameters such as
pain reduction and physical function.
We investigated balance with both eyes open and closed and knees in
extension and flexion separately. In group 1, none of these parameters
had significant changes, and the other two groups had significant
improvements. The strength exercise group showed an increase in
several parameters (i.e., more tested positions) and higher significance
values than the endurance exercise group. Strengthening the quadriceps
femoris muscle becomes highly important in exercise therapy in
OA because it is the most significant antigravity muscle of the lower
extremity and has a significant role in maintaining balance. Bellew et al.
(24) investigated a 12-week low-intensity quadriceps strength exercise
program in the elderly and did not find an improvement in balance
measures. These conflicting results in the literature are possibly due to
methodological differences among studies, OA stage of the patients,
exercise type, and intensity of the exercise sessions. Kim et al. (25)
compared strength and balance exercises in different platforms in a 30-
knee OA patient cohort. After 6 weeks, no between-group difference was
found in balance, but balance measures improved significantly within
the groups before and after experiments. Our study supports the findings
of Kim et al. (25) by showing improvements in balance measures in the
strength exercise group.
Study Limitations
This study is not a double-blind placebo-controlled randomized study.
However, for most patients presenting with knee OA, nonintervention
may lead to dropouts and an unacceptable option for patients. As all
groups showed improvement, there is a need for studies with larger
study samples. Long-term exercises with different load intensities and
duration should be addressed in future studies by increasing the sample
size.
Conclusion
Exercise therapy should be performed in addition to controlling pain
and inflammation in the treatment and rehabilitation of patients with
OA. Even though isometric exercises are widely used in this setting, to
shorten the time of intervention for improving muscle strength, slowing
disease progression, and reducing the risk of falling by improving
balance in this population, we believe that including isotonic strength
or endurance exercises to support the treatment should be considered.
Ethics Committee Approval: The Clinical Research Ethics Committee
of İstanbul University, İstanbul Faculty of Medicine (approval number:
2016-249, date: 29.02.2016).
Informed Consent: In total, 46 patients volunteered for the study and
signed the informed consent forms.
Peer-review: Externally peer-reviewed.
Authorship Contributions: Surgical and Medical Practices - D.Ç., T.Ş.,
L.Ö.; Concept - D.Ç., S.Y., L.Ö.; Design - D.Ç., S.Y., L.Ö.; Data Collection or
Processing - D.Ç., S.Y., T.Ş., Ş.D., Ö.B.G., L.Ö.; Analysis or Interpretation
- D.Ç., S.Y., T.Ş., Ş.D., Ö.B.G., L.Ö.; Literature Search - D.Ç., S.Y., T.Ş., Ş.D.,
Ö.B.G.; Writing - D.Ç., S.Y., T.Ş., Ş.D., Ö.B.G., L.Ö.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: This study was supported by İstanbul University
Scientific Research Projects Unit (project number: 22047).
Table 6. Comparison of balance scores before and after exercise
Parameters
Group 1 Group 2 Group 3
BE AE BE AE BE AE
Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD
EOKE 0.50±0.13 0.48±0.20 0.62±0.14 0.43±0.13*** 0.74±0.43 0.54±0.30
ECKE 1.12±0.45 0.91±0.32 1.40±0.82 1.12±0.46 1.79±1.13 1.22±0.66*
EOKF 0.74±0.38 0.71±0.22 0.92±0.42 0.70±0.25*1.17±0.65 0.94±0.54*
ECKF 2.18±0.88 1.92±0.82 2.80±1.15 1.76±0.56*** 2.22±1.18 1.92±0.97
EOKE: Eyes open knee in extension, ECKE: eyes closed knee in extension, EOKF: eyes open knee in exion, ECKF: eyes closed knee in exion, BE: before exercise, AE: after exercise, SD:
standard deviation, *: p<0.05, **: p<0.01, ***: p<0.001

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