@2024 Afarand., IRAN

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ISSN: 2252-0805    The Horizon of Medical Sciences 2016;22(3):193-199

Background
One of the most common types of arthritis in people over 40 years old is osteoarthritis that it is somehow even more common than heart diseases, unusual blood pressure or even diabetes [1].
Previous Studies
[2-9]. Patients suffering from Knee osteoarthritis face with kind of balance disorder that can be observed as increasing the range and velocity of COP of the body [4, 5, 10, 11]. …[12-14] The conducted studies have just focused on the evaluation of displacement of the pressure center in two directions and as we know, the static balance and stability itself is composed of 24 parameters that among 6 parameters, the sum of passed trajectory length by body pressure center, motion range of pressure center and COP velocity in anterior-posterior and medial-lateral directions are more reliable to evaluate the balance [15].
Aim(s)
This study examined with the aim to evaluate the standing balance of people suffering from knee osteoarthritis and the study approach of six balance parameters of the sum of passed trajectory length, motion range and COP velocity of body in two different directions in this group of patients and its comparison with other healthy people.
Research type
This is a case-control study.
Research society, place and time
In this study 15 patients suffering from knee osteoarthritis were studied in musculoskeletal research center of Isfahan Medical Sciences University in 2015.
Sampling method and number
15 patients suffering from knee osteoarthritis were selected and studied according to the study criteria by stratified sampling among patients referred to Physiotherapy Clinic of Rehabilitation College and Alzahra hospital of Isfahan. Also, 15 healthy people were selected from Isfahan city as a control group in order to evaluate and achieve greater transparency in test results. People who clinically had ACR criteria including: knee pain on most days of previous month, crepitus (joint sound) in active motion of joint, morning stiffness less than 30 minutes, age over 45 years old and swelling of the knee bone in examination, participated in the research [16].
Used devices&materials
Patients were divided into 4 groups of zero to three according to osteoarthritis changes in knee X-ray based on the findings of this disorder; zero degree was the knee joint normal space, One degree was the medial joint subchondral sclerosis, Two degree was the decrease of the medial joint space and Three degree was the decrease of joint space on both sides [17]. Data was collected using hardware and proprietary software of Kistler force platform as well as coordinated hardware and software of qualisys (track manager Version 7.2, Build No. 771, Switzerland)[18-22]. There are different parameters to evaluate the static balance; two of the most common parameters include the range of pressure center changes in Mediolateral plate and Anterior-posterior plate. Kistler force platform device with piezoelectric force transducers is used to measure pressure center as a good approximation of pulsation. Pulsation during a gradual standing is defined by motion of the body’s center of gravity in the transverse plane. These motions are due to small deviations of center of gravity towards vertical ground reaction force. Many researchers carried out the pulsation measurement through the measurement of pressure center on force platform [23, 24]. The reliability of force platform based on the range of pressure center changes has been measured by many researchers [24-27]. Balance and stability of patients were evaluated relatively before starting the balance evaluation tests. Patients were asked to announce immediately in case of tiredness during the test in order to avoid the impact of fatigue factor on results, and patients took rest between each iterative test for one to two minutes. After measuring the height and weight, patients were asked to stand in the center of force platform barefoot and while both feet shoulder width apart and hands hanging beside the body and looking at a certain point in 4-meter distance. Patients repeated it three times and each time stood on force platform for 60 seconds and maintained the balance [5-11]. The mean of the displacement in the anterior-posterior and medial-lateral directions as well as the mean of COP velocity were used to evaluate static stability. After collecting data and numerical process by mentioned proprietary software, data processed in Microsoft Excel Version 2010. Data analyzed with significance level of less than 0.05 via SPSS software version 19. Descriptive statistics was used in order to calculate the frequencies, mean and standard deviation and inferential statistics was used to evaluate significant difference between the mean of each research variables in both groups. The normal distribution of all data was evaluated by Shapiro-Wilk test results in inferential statistics. Logarithmic distribution parameter was used to change the nonparametric variables to parametric variables. Two-sample T-test was used to evaluate the significant difference between the two groups of participants.
Findings by Text
15 males suffering from knee osteoarthritis and 15 healthy males as a control group were studied (Table1). There was not any significant difference of the mean of the sum of passed trajectory length parameter by pressure center in the anterior-posterior (Y-axis) between healthy people and patients with knee osteoarthritis. However, this parameter had a significant difference in healthy people and patients group in terms of medial-lateral direction (X-axis). Also, the mean of motion range parameter (excursion) and COP velocity had a significant statistics difference in the anterior-posterior and medial- lateral directions between the two groups (Table 2).
Main comparison to the similar studies
Standing balance and static standing decreases in patients suffering from knee osteoarthritis in comparison with the control group due to five significant parameters out of 6 studied parameters which are the standing stability scale; the reason can be impaired proprioception and coordination disorders in neuro-musculoskeletal system that why results of some conducted studies related to the balance disorder represent this relationship [4, 10, 11]… [28-29].
Suggestions
It is suggested to use this study results in order to treatment planning of the patients suffering from knee osteoarthritis so that they can have active and efficient roles in daily activities and works associated with the balance. One of the suggestions in the rehabilitation section is maneuver on the things related to balance control such as proprioception improvement, pain relief and quadriceps muscles increase in patients suffering from knee osteoarthritis.
Limitations
We faced some problems in the stage of access to participants and during the test performance that we did not inevitably consider any restrictions for participation of patients with bilateral and unilateral osteoarthritis. Also, patients with grade 3 in knee graph did not participate in the study due to insufficient number of patients suffering from osteoarthritis involved with the lateral knee compartment.
Conclusions
Standing stability (static stability) reduces in patients suffering from knee osteoarthritis in comparison with healthy people.
Acknowledgments
We appreciate all participants that cooperate with us in this study.
Conflict of interest
Non-declared
Ethical Permissions
Examinees signed conscious consent form before participating in the study. Methods and the way of tests performance were explained completely and simply to the participants.
Funding Sources
This article is an approved research project (Code No: 393819) of Isfahan Medical Science University Research Council.

TABLES and CHARTS

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