The Effects of Isokinetic Exercises on Muscle Strength, Joint Position Sense, and Kinesiophobia in Patients With Multiple Sclerosis: a Randomized Controlled Trial
Phase: NA
Conditions: Multiple Sclerosis
Sponsor: Aksaray University Training and Research Hospital

18.12.2018 
The effects of isokinetic exercises on muscle strength, joint position sense, and 
kinesiophobia in patients with multiple sclerosis: a randomized controlled trial 
Melek Aykut Selçuk1 
Burcu Duyur Çakıt2 
Hakan Genç2 
Barış Nacır2 
Sühan Taşkın2 
Ufuk Ergün3 
1. Clinic of Physical Medicine and Rehabilitation, Aksaray University Training and 
Research Hospital, Aksaray, Turkey 
2. Clinic of Physical Medicine and Rehabilitation, Ankara Training and Research 
Hospital, Health Sciences University, Ankara, Turkey 
3. Clinic of Neurology, Kırıkkale University Medical Faculty, Kırıkkale, Turkey 
 
Principal Investigator 
Phone number: 90 555 528 94 93 
Mail address: mlk.aykut@gmail.com 
Address: Clinic of Physical Medicine and Rehabilitation, Aksaray University Training and 
Research Hospital, Aksaray, Turkey 
 
The study has no trial registration number yet. 
Approval date and reference number of Ethics Committee of Aksaray University Training and 
Research Hospital, Aksaray, Turkey: 29.07.15, 603/5070 
 
 

 
The effects of isokinetic exercises on muscle strength, joint position sense, and 
kinesiophobia in patients with multiple sclerosis: a randomized controlled trial 
ABSTRACT 
Objective: To evaluate the effects of isokinetic exercises on muscle strength, knee 
joint position sense, pain, kinesiophobia, and quality of life in patients with multiple sclerosis. 
Design: Randomized controlled trial. 
Setting: Outpatient clinic. 
Participants: Sixty patients with multiple sclerosis. 
Interventions: Fifty patients were randomized to an isokinetic exercise (n:25) or 
home exercise programme (n:25). 
Outcome measures: The outcome measures were the peak torque/body mass index of 
quadriceps and hamstring muscles at 60°/s and 180°/s velocities, the hamstring/quadriceps 
ratios at the same velocities, absolute angular errors of the 15°, 45°, and 60° and the mean 
absolute angular error of joint position sense of the less and more affected knees, and the 
scores of Multiple Sclerosis Quality of Life-54, Visual Analogue Scale, and Tampa Scale of 
Kinesiophobia. 
INTRODUCTION 
In one study, the muscle strength of the quadriceps and hamstring, which were tested 
with the isokinetic muscle strength test, were found to be lower in patients with multiple 
sclerois (MS) than the controls (1). In another study, bilateral muscle strength of the 
quadriceps and hamstring were shown to be related with walking speed, balance, and 
functional capacity (2). Therefore, the authors concluded that muscle strengthening exercises 
for the quadriceps and hamstring should be included in the rehabilitation program of MS 
patients. 
It is known that slowing afferent proprioceptive conduction and impaired central 
integration of the proprioception are the main causes of balance deficit in MS patients. 
Proprioception impairment, often seen in patients with MS, negatively affects the joint 
position sense (JPS), balance, and posture. Joint repositioning, muscle strengthening, 

plyometric, balance, coordination and vibration exercises are recommended to improve JPS, 
proprioception, and balance in this patient group (3). 
It has been reported that exercise training improves and/or maintains functional 
capacity, strength, endurance, fatigue, quality of life (QoL), depression, cognition, and 
chronic disease risk factors among MS patients. The current evidence suggests that exercise 
training is generally safe for MS patients and not associated with an increased relapse risk. 
Resistance and endurance training modalities are the major types of exercises in MS patients 
(4).  
There are not enough studies on isokinetic muscle strengthening exercises in MS 
patients with muscle weakness. Robineau et al. (5) and Aubry et al. (6) reported that 
isokinetic knee flexion-extension exercises improved quadriceps and hamstring muscle 
strength and control of the knee in this patient group. Manca et al. (7) investigated the 
efficiency of isokinetic ankle dorsiflexor training, and the muscle strength of ankle 
dorsiflexors improved significantly in MS patients. 
Kinesiophobia is defined as “an excessive, irrational and debilitating fear of physical 
movement and activity resulting from a feeling of vulnerability to painful injury or reinjury” 
and is related with the disability level (8). MS patients show fear avoidance beliefs and 
behaviors which are related with pain. Although catastrophizing and fear avoidance beliefs 
and behaviors have been reported in MS patients, they have not been investigated in detail (9). 
To the best of our knowledge, no study has explored the effects of isokinetic training 
on knee JPS, pain, kinesiophobia, and QoL in MS patients. Therefore, in the current study, we 
aimed to observe the knee JPS and kinesiophobia level, their relationships with QoL, and the 
effects of isokinetic exercises on these variables.  
 
METHODS 
Following the Helsinki Declaration, the study was approved by the Ethics Committee 
of Ankara Training and Research Hospital, Health Sciences University (29.07.15, 603/5070). 
This prospective randomized controlled trial aimed to recruit 60 patients with MS from the 
physical medicine and rehabilitation clinic of Ankara Training and Research Hospital, Health 
Sciences University, Ankara, Turkey (June 2016 to June 2017). 
Participants 

Individuals were included if they had definite relapsing remitting MS and secondary 
progressive MS diagnosis, mild and moderate MS determined by Kurtzke Expanded 
Disability Status Scale (EDSS) scores below 6.5, and a disease duration of more than one 
year. The exclusion criteria were; having an acute exacerbation within the last three months, 
intravenous pulse steroid therapy in the last four weeks, grade 3-4 spasticity according to the 
Modified Ashworth Scale, severe vision impairment, severe fatigue and depression, past knee 
surgery, other neurologic diseases, systemic diseases, pregnancy, and having received an 
exercise program within the last four weeks. Fifty patients who met the inclusion criteria were 
enrolled in the study (Figure 1). 
Procedure 
Fifty patients were randomized to two groups: isokinetic exercise (Group 1) (n=25) 
and home exercise (Group 2) (n=25). Randomization was completed using sequentially 
numbered, opaque envelopes by the investigator. All patients gave informed consent before 
the assessment. The outcome measures were assed initially and at eighth week after the 
treatment. Group 1 performed isokinetic concentric quadriceps and hamstring strengthening 
exercises under supervision and Group 2 performed lower extremity muscle strengthening and 
balance exercises at home.  
Outcome measures 
The patients completed the questionnaire about age at diagnosis, disease duration, type 
of disease, and medical history.  
Muscle strength and JPS testing 
Muscle strength and knee JPS were tested by an isokinetic dynamometer (Biodex 
System 3 Pro Multijoint). Before muscle strength and knee JPS testing, the patients were 
informed about the procedure. First knee JPS was tested, and then muscle strength was 
measured. The machine was calibrated before the procedure. Before muscle strength testing, 
the patients performed quadriceps and hamstring stretching exercises and on-site counting for 
five minutes for warming-up. The seat angle was set to 85° and the patient was asked to sit 
down. Appropriate parts for knee testing were placed in the dynamometer. The lateral femoral 
condyle, which is the rotation axis of the knee, was aligned to the rotation axis of the 
dynamometer. The patients were stabilized by thoracic, pelvic and thigh belts. The patient’s 
leg was bound to the leverage equipment from the upper part of the medial malleolus. During 

the test, the patients were asked to place their arms sideways. After determining the range of 
motion and gravity correction for the mass of the limb, the patients performed three 
submaximal warm-up contractions at 60°/s angular velocity. After warming up, the patients 
rested for 10 seconds, and then performed five maximal concentric knee flexion-extension at 
60°/s and 10 maximal concentric knee flexion-extension at 180°/s angular velocities, 
separated by 20 seconds of seated static recovery. Both the more and less affected legs were 
tested in order, two minutes after the seated static recovery period. During the test, the 
quadriceps and hamstring peak torque (PT), the peak torque (PT)/body mass index (BMI), and 
the hamstrings/quadriceps (H/Q) ratio were evaluated at 60°/s and 180°/s angular velocities in 
Newton/meter (N/m) (10). 
After the preparation, positioning and stabilization, knee JPS was tested according to 
the active-active angular reproduction method. The position of the knee at 90° flexion was 
accepted as the starting angle; i.e., 0°. The patients moved their leg from 0°(starting angle) to 
45°, 15° and 60° extension direction in sequence to prevent a learning effect. With eyes open, 
the patients held their leg at the starting angle for 10 seconds and then moved it to 45° (target 
angle), held the leg at that angle for 10 seconds, and then returned to the starting angle. This 
procedure was repeated three times and the patient was encouraged to focus on maintaining 
the target angle. After keeping their leg at the starting angle for 10 seconds with eyes closed, 
the patients were asked to move their leg to the 45° angle. The angle predicted by the patients 
was recorded and the same process was repeated three times. Estimating the target angel 
procedure was repeated at 45°, 15°, and 60° and for both the more and less affected legs. 
After the JPS testing, three angles estimated by the patients were averaged, and the angular 
error (AE) was calculated for each target angle. Absolute angular error (AAE) was calculated 
by averaging the AEs, regardless of the numbers being negative or positive. The AAE values 
of the three target angles were averaged to obtain the mean AAEs (MAEs) (11, 12). 
Evaluation of pain and kinesiophobia  
Pain intensity was evaluated with the Visual Analogue Scale (VAS). Using a ruler, a 
10 cm line was drawn which provided a range of scores from 0-100. Then the patients marked 
the point that showed their pain intensity on this line. A higher score in VAS indicates greater 
pain intensity (13). Kinesiophobia was evaluated using the Tampa Scale of Kinesiophobia 
(TSK), which is a 17-item self-report survey based on a four-point Likert scale developed as a 
measurement tool for fear of movement and/or (re)injury. If the total score was above 37 
points, the patient was considered to have a high level of kinesiophobia (14). 

Evaluation of quality of life 
The Multiple Sclerosis Quality of Life-54 (MSQoL-54) is a multidimensional health-
related QoL measure that combines both generic and MS-specific symptoms in a single 
instrument. The cross cultural adaptation and validation of the MSQoL-54 inventory in a 
Turkish population was undertaken by Idıman E. et al. in 2006 (15). In the current study, we 
used the total, physical and emotional composite and pain scores of the Turkish MSQoL-54. 
Interventions 
Isokinetic training program 
Before the exercise program, the patients performed hamstring and quadriceps 
stretching exercises and on-site counting for five minutes. After the warm-up, the patients did 
concentric/concentric quadriceps and hamstring muscle strengthening exercises in increasing 
intensity, to the extent that they could tolerate. The isokinetic exercise program was 
implemented over eight weeks, twice a week on non-consecutive days under the supervision 
of a doctor. The number of repetitions undertaken by the patients over the program were as 
follows: first week 5 at 60°/s and 10 at 180°/s, second week 10 at 60°/s and 15 at 180°/s, third 
week 15 at 60°/s and 20 at 180°/s, fourth week 20 at 60°/s and 30 at 180°/s, and in the last 
four weeks 20 at 60°/s and 40 at 180°/s angular velocities. Each block of 10 repetitions were 
performed as a set. 
Home exercise program 
The patients undertook lower extremity strengthening and balance exercises three 
times a week for eight weeks without supervision. They started with three repetitions, which 
was gradually increased to 10-15. The patients were called two times a week to inquire about 
exercise continuity and encouraged to undertake the recommended exercises.  
Statistical Analysis 
The data were analyzed using the Statistical Package for the Social Sciences (SPSS) 
software version 15.0. The sample characteristics were summarized using descriptive 
statistics. Descriptive statistics tables were created for numerical variables, and frequency 
tables were constructed for categorical variables for both groups. The Kolmogorov-Smirnov 
test was used to test the normality of data. The Mann-Whitney U test was conducted to 
compare the two groups. The Wilcoxon test was performed for the comparison of before and 
after treatment values within the groups in terms of muscle strength, knee JPS, kinesiophobia, 
and QoL variables. The Spearman correlation test was utilized for the evaluation of 
relationships between muscle strength and knee JPS. The level of statistical significance was 
set at p<0.05.