Aziadna G, Abu Rashid M, Treister-Goltzman Y. Knee osteoarthritis in two ethnic groups in southern Israel: Risk factors and the role of Muslim prayer. World J Orthop 2026; 17(7): 121442 [DOI: 10.5312/wjo.121442]
Corresponding Author of This Article
Yulia Treister-Goltzman, MD, PhD, Family Medicine, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel. yuliatr@walla.com
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Aziadna G, Abu Rashid M, Treister-Goltzman Y. Knee osteoarthritis in two ethnic groups in southern Israel: Risk factors and the role of Muslim prayer. World J Orthop 2026; 17(7): 121442 [DOI: 10.5312/wjo.121442]
Co-first authors: Gasem Aziadna and Majed Abu Rashid.
Author contributions: Aziadna G contributed to the conceptualization and methodology of the study, investigation, validation, and writing-review and editing; Abu Rashid M contributed to the conceptualization and methodology of the study, investigation, validation, and writing-review and editing; Treister-Goltzman Y contributed to the conceptualization and methodology of the study, data curation, formal analysis, software, supervision, visualization, validation, writing-original draft, and writing-review & editing. Aziadna G and Abu Rashid M contributed equally to this work as co-first authors.
AI contribution statement: AI tools were not used during manuscript preparation. AI tools were not used to generate original scientific data, perform independent scientific analyses, or draw scientific conclusions.
Supported by Faculty of Health Sciences, Ben-Gurion University of the Negev.
Institutional review board statement: Prior to recruitment approval was obtained from our institutional/regional/national research ethics committee: The Ethics Committee of Clalit health Services (approval No. com1-0085-17).
Informed consent statement: The privacy rights of human subjects have been observed, and informed consent was obtained from all the participants.
Conflict-of-interest statement: There is no conflict-of-interest.
STROBE statement: The authors have read the STROBE Statement-checklist of items-and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Data sharing statement: The data that support the findings of this study are available from the corresponding author, upon reasonable request.
Corresponding author: Yulia Treister-Goltzman, MD, PhD, Family Medicine, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel. yuliatr@walla.com
Received: April 10, 2026 Revised: May 28, 2026 Accepted: June 24, 2026 Published online: July 18, 2026 Processing time: 111 Days and 19.1 Hours
Abstract
BACKGROUND
The unique characteristics of the principal ethnic populations of southern Israel could affect the prevalence osteoarthritis of knee (OAK). Traditional Muslim prayer, which involves bending of knees and standing with bent knees five times each day may be associated with lower odds of OAK.
AIM
To compare the prevalence of OAK and factors associated with it in two ethnic groups in southern Israel. Another aim was to assess the effect of traditional prayer on the prevalence of OAK and its severity.
METHODS
A cross-sectional study based on interviews of patients aged ≥ 50 years in primary care clinics in a Bedouin and Jewish cities in southern Israel. The participants completed sociodemographic and medical questionnaires, and the Western Ontario and McMaster Universities Osteoarthritis Index. Multivariable logistic models were developed for OAK in each of the ethnic sectors.
RESULTS
There were 182 participants from the Jewish sector and 171 from the Bedouin sector. Seven Bedouins (4%) took part in regular physical activity compared to 42 (23%) Jews. The prevalence of OAK in the two communities was about 29%. Among Bedouin participants, knee osteoarthritis was reported in 9.5% of those who performed the regular traditional prayer compared with 70.9% of those who did not. In the multivariable logistic analysis, body mass index (BMI) and diabetes were associated with higher odds of OAK [odds ratio (OR) = 1.18, P < 0.001 and OR = 2.64, P = 0.019, respectively] among Jews and participation in physical activities with lower odds (OR = 0.18, P = 0.031). Among Bedouins BMI was associated with higher (OR = 1.19, P = 0.008) and prayer with lower odds (OR = 0.045, P < 0.001).
CONCLUSION
There was an inverse association between traditional Muslim prayer and OAK. To improve OAK morbidity, efforts should be focused on physical activity, which is particularly low among Bedouins, and BMI.
Core Tip: This cross-sectional study compared osteoarthritis of knee (OAK) prevalence and associated factors among Jewish and Bedouin adults aged ≥ 50 years in southern Israel. Despite distinct lifestyles, OAK prevalence and symptom severity were similar between the groups. Higher body mass index was positively associated with OAK in both populations, while diabetes was positively associated with OAK in Jews. Notably, traditional Muslim prayer was strongly associated with lower OAK prevalence and milder symptoms among Bedouins, suggesting a protective effect comparable to regular physical activity among Jews. These findings support culturally tailored preventive strategies, while acknowledging that causality cannot be inferred.
Citation: Aziadna G, Abu Rashid M, Treister-Goltzman Y. Knee osteoarthritis in two ethnic groups in southern Israel: Risk factors and the role of Muslim prayer. World J Orthop 2026; 17(7): 121442
There is evidence in the medical literature of an association between ethnic origin and the prevalence osteoarthritis of knee (OAK)[1,2] and its manifestations including pain[3,4]. There are several possible explanations for this association. One explanation is a genetic effect. Polymorphisms in different regions of the growth differentiation factor and interleukin 16 play an important role in the development of osteoarthritis (OA)[5-7]. Another possible explanation is an environmental effect. It is reasonable to assume that individuals who live in an identical environment share identical lifestyle risk factors. For example, in communities where smoking is prevalent, the consumption of alcohol and obesity leads to a higher rate of OA[8]. Habits such as prolonged squatting, or widespread bicycle riding in different populations increase the risk for OAK[9].
Two principal populations live in southern Israel, Bedouin Muslims and Jews. The Jewish population follows a Western lifestyle, while the Bedouin population is a traditional Arab community with unique customs characterized by traditional dress, traditional Muslim prayers, and one of the highest birthrates in the world[10]. These unique characteristics could affect the prevalence of OAK. Traditional Bedouin clothing covers most of the woman’s body preventing exposure to the sun, reducing Vitamin D levels and, thus, increasing the risk for OAK[11]. Several studies have shown a direct association between parity and risk of OAK[12-14] and the subsequent risk of for knee replacement surgery[13]. This factor can also lead to increased prevalence of OAK in the Bedouin population. Another factor that could increase the risk for OAK in this population is the high prevalence of obesity among older Bedouin women[15].
In contrast, traditional Muslim prayer, which involves bending of knees and standing with bent knees five times each day has been hypothesized to influence the development and manifestations of OAK as a result of stretching the soft tissue around the knee while praying. Very few studies have looked at the effect of traditional Muslim prayer and its manifestations on OAK. One study checked the prevalence of OAK and its symptoms in two populations from the same ethnic origin, living in the same geographic region, but differing in their faith and prayer style (Buddhist and Muslim). The investigators found a lower prevalence of OAK and knee pain in the traditional Bedouin population compared to the Buddhist population[16]. Another study reached the conclusion that Muslim prayer does not affect OAK in its clinical and radiological manifestations[17]. Because of the high prevalence of OAK and its functional consequences, taken together with the small amount of research focused on ethnic differences in this disease, we believe that the study of this issue is of great importance.
The aims of this study were to compare the prevalence of OAK symptoms in primary care in the population of patients over the age of 50 years in two ethnic populations in southern Israel. Additional aims were to assess the association between various factors for OAK in the two populations, and to assess the effect of prayer in the sub-group of Muslim Bedouin patients on OAK.
MATERIALS AND METHODS
This cross-sectional study was conducted in two primary care clinics in Rahat, one of the largest Bedouin cities in Israel’s southern region and in Beer-Sheva, the largest Jewish city in the region. The study population included all patients over the age of 50 years who came to the study clinics for any reason. The first study questionnaire included socio-demographic data, risk factors for OAK, self-reported physician-diagnosed OAK, and regular sports-related physical activity. It was constructed by the authors in Hebrew and translated into Arabic using the backward translation method. The second questionnaire was the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). This is a validated and reliable questionnaire for the assessment of OAK symptoms. It contains 24 questions in 3 sub-groups relating to pain, rigidity, and physical function. For each item the patient ranks the severity of the symptom on a scale from 0-4. There are validated Hebrew and Arabic versions of WOMAC[18,19]. WOMAC was administered only to participants who reported a prior physician diagnosis of OAK during the interview. Patients who met the inclusion criteria were asked, at the end of their clinic visit, to participate in a research study. Those who agreed to participate were interviewed by the investigators (Aziadna G and Abu Rashid M) using a structured questionnaire. Jewish patients were interviewed in Hebrew and Bedouin patients in Arabic. The study period was between January 8, 2018 and November 24, 2021. Prior to recruitment, approval was obtained from our institutional/regional/national research ethics committee: The Ethics Committee of Clalit health Services (approval No. com1-0085-17, date Dec 3 2017). The privacy rights of human subjects were observed, and informed consent was obtained from all the participants.
Sample size calculations
The reported prevalence rate for OAK in patients over 50 years of age is about 25% in Europe and the United States[20]. The Jewish population practices a Western lifestyle for the most part, so our assumption was that prevalence of OAK in this population would be about 25%. Reports from Muslim countries point to a lower prevalence rate of about 13%[20]. Based on these assumptions the sample size needed to identify a statistically significant difference between the two study population was 167 participants in each group. Considering possible missing values, we planned to interview 182 patients in each group to reach a power of 80% with a confidence level of 95%.
Statistical analyses
Data analyses were conducted with the SPSS software (version 26) and the R program (version 4.0.5). Categorical variables are described as n (%). Continuous variables such as age, are described as mean ± SD or median and interquartile range (IQR). We tested for differences between the groups in socio-demographic and other characteristics, and OAK. The prevalence of OAK and its symptoms was compared between the two ethnic groups. In the Bedouin group we tested for an association between prayer and OAK. Categorical variables were tested with the χ2 or Fisher exact test in accordance with cell size. Continuous variables were tested with the Mann-Whitney or student’s t-test in accordance with the nature of the data distribution. Multivariable logistic regression models were developed to identify variables associated with OAK in each ethnic group. Variables associated with OAK in the univariate analysis at a significance level of P < 0.10 were entered into the models using the enter method. Age, sex, and number of children were retained in the models regardless of statistical significance, based on prior clinical knowledge and evidence from the literature. Multicollinearity was assessed using the variance inflation factor (VIF), and the absence of significant multicollinearity among the independent variables was ensured. Statistical significance was set at P < 0.05 for all tests.
RESULTS
Background characteristics of the study population
Table 1 shows a comparison of the patients’ baseline characteristics. There were 353 participants in the study, 182 from the Jewish sector and 171 from the Bedouin sector. Three patients who were asked to join the study did not give their consent to be interviewed. There were statistically significant differences in most background characteristics between the groups. The mean age for the total population was 62 years; 63 years among Jews and 61 among Bedouins (P = 0.009). The mean number of children was six for the total population; much higher in the Bedouin group at 8 compared to 4 in the Jewish group (P < 0.001). There was no significant difference between the groups in terms of sex, with 52% of the total population females. The Bedouins had a higher mean body mass index (BMI) (28.3 ± 4.3) compared to the Jews (27.1 ± 5.1) (P = 0.015). Although there was no difference in the rate of patients with self-reported physician diagnosis of osteoarthritis (about 29% in the total population), more Jews suffered from knee pain (59% vs 43%, respectively). There were no significant differences between the groups in the rate of arthroscopic surgery or knee replacement surgery. A higher percentage of Jews reported prior knee trauma (20% vs 6%, respectively). Only seven Bedouin participants (4%) carried out regular physical activity compared to 42 Jews (23%).
Univariate tests and multivariable models for predicting OAK
Supplementary Table 1 shows univariate associations between background characteristics and OAK. There were statistically significant associations between OAK and age, sex, number of children, BMI, diabetes, and physical activity. In addition, in the Bedouin group there was a statistically significant association between traditional prayer and OAK (Figure 1).
Figure 1 Prevalence of knee osteoarthritis among worshipers and non-worshipers in the Muslim Bedouins subgroup. P < 0.001 by χ2 test.
Table 2 shows the results of the logistic regression analysis for the association of different factors with OAK. BMI was associated with higher odds of OAK in both groups at odds ratio (OR) = 1.12 (P < 0.001) for Jews and OR = 1.19 (P = 0.008) for Bedouins. In the Jewish group diabetes (OR = 2.64, P < 0.001) and physical activity (OR = 0.18, P = 0.031) were associated with OAK and in the Bedouin group traditional prayer was associated with reduced odds of OAK (OR = 0.045, P < 0.001). Supplementary Table 2 demonstrates that there was no evidence of significant multicollinearity among the independent variables (all VIF values were ≤ 1.2).
Table 2 Multivariate models for knee osteoarthritis in the two ethnic populations.
Table 3 shows a comparison of Jewish and Bedouin participants with OAK. There were no significant differences between the groups in any of the subscales of the WOMAC questionnaire or in overall severity. There were significant differences in the Bedouin group between individuals who participated in traditional prayers and those who did not in terms of pain, with median (IQR) of [5.0 (4.0-8.0) vs 12.5 (10.0-14.0), P < 0.001], rigidity [2.0 (2.0-4.0) vs 4.0 (4.0-6.0), P < 0.001], and function [17.0 (13.0-28.0) vs 44.0 (33.0-49.8), P < 0.001].
Table 3 Comparison of osteoarthritis of knees severity between the two ethnic sectors and between worshipers and non-worshipers in the Bedouin ethnic group.
The results of this study indicate that the prevalence of OAK in patients 50 years of age and above was almost identical in the two ethnic groups at about 29%. This prevalence rate is higher than reported in this age group from Europe, the United States, and Asian and African countries[20,21]. A possible explanation for this result is the higher rate of risk factors for OAK in Israel. Based on the results of a 2019 Israeli survey, overweight or obesity were seen in one half of the adult populations, which increased with increasing age[22]. The high birth rate in the Jewish population in Israel, which is higher than in other Western countries[23], and the birth rate in the Bedouin population in Israel, which is higher than in Muslim countries[10] could contribute to the high prevalence of OAK.
Traditional dress for Bedouin women covers most of the body and may be associated with reduced sun exposure and lower vitamin D levels. This has been proposed as a potential contributing factor to musculoskeletal conditions, including osteoarthritis; however, vitamin D levels were not measured in the present study, and this explanation remains speculative[24]. There was no significant difference in severity of symptoms, measured by WOMAC, between the two groups, but in Muslims who pray there was a lower frequency of OAK, a milder degree of severity, and lower scores for the three subscales of the WOMAC questionnaire (pain, rigidity, and function), compared to those who do not pray regularly. Muslim praying entails repetitive movements of squatting, lying down, and sitting that are practiced five times a day and are comparable to physical activity of moderate intensity. Regular mild to moderate physical activity is known to be a protective factor against the development of OAK and its worsening over time[25]. Deep knee bending during prayer causes significant stretching of the soft tissue and reduced pressure on the joint cartilage[17,26]. A recent review described many additional physiologic benefits of traditional Muslim prayer[26]. Prayer movements involve all of the body’s joints with alternating contraction and relaxation of muscles. There are descriptions of the beneficial effects of Muslim prayer on the muscles and joints of the cervical, thoracic, and lumbar spine, the shoulders, the wrists, the hips, the knees, the ankles, and the feet. In addition to the mechanical effect there are beneficial effects on the nervous system, on posture, on dynamic balance and coordination, and on pulse and blood pressure[26,27]. There is also evidence pointing to a direct beneficial effect of additional muscles such as the postural and para-spinal muscles on the risk for developing OAK[28].
Indeed, the results of the multivariate logistic regression for each of the ethnic populations demonstrated a strong inverse association between traditional Muslim prayer, which includes repetitive bending of the knees, and OAK, similar to the protective association observed for physical activity in the Jewish population. Traditional prayer may explain, in part, the fact that although only a few Bedouins practiced physical activity, the prevalence and severity of OAK was not higher in this population than in the Jewish population. However, this was a cross-sectional study without a temporal elemental, so determination of causality was not possible. Reverse causation is also possible, as patients with OAK, particularly those with more severe symptoms and functional limitation, may reduce or stop traditional prayer because of difficulty performing the required movements. Therefore, the observed association should not be interpreted as proof of a causal protective effect of prayer against OAK.
As mentioned above, very few studies looked at the effect of traditional Muslim prayer on the prevalence of OAK and its manifestation. One study found a protective effect of Namaz prayer for OAK[29]. Another study showed a lower prevalence of OAK among praying Muslims compared to an identical population in terms of genetics and geographical region, who practice Buddhism[16]. In this study there was no difference in the severity of OAK using the WOMAC questionnaire. In contrast, another study found that the range of knee movement in OAK patients was greater among praying Muslims compared to non-Arab OAK patients[30]. A case-control study did not find radiological differences in OAK between those who pray and those who did not, and even demonstrated a negative effect on bone density and the development of Heberden and Bouchard’s nodes among those who prayed[17]. Recent systematic reviews and meta-analyses have highlighted persistent racial and ethnic disparities in osteoarthritis presentation, treatment utilization, and outcomes, including differences in access to pharmacologic therapies and joint replacement surgery outcomes[31-33]. These findings support the importance of examining osteoarthritis within specific ethnic and cultural contexts and may help contextualize the differences observed in the present study.
This study had limitations. The study population was a convenience sample, which can entail a selection bias. For example, patients who come to the clinic may be less healthy and have a higher prevalence of OAK than those who do not. Furthermore, they may also have chronic diseases such as diabetes mellitus that could cause a false-positive increase in the prevalence of OAK as well as associations with other chronic diseases. On the other hand, patients with OAK may have greater difficulty coming to the clinic because of limited mobility, leading to a false-negative reduction in prevalence. Therefore, the prevalence estimates observed in the present study may differ from those in population-based studies and may limit the generalizability of the findings to the broader community population. Part of the data collection period overlapped with the coronavirus disease 2019 pandemic and related lockdowns in Israel beginning in March 2020. These restrictions may have affected recruitment rates, healthcare-seeking behavior, and physical activity levels among participants. Another limitation is that physical activity assessment in the present study focused mainly on regular participation and did not include occupational, household, or culturally related daily activities such as squatting, kneeling, or prolonged floor sitting. These activities may differ substantially between the Bedouin and Jewish populations and could affect the risk and severity of OAK. Therefore, residual confounding related to unmeasured non-sport physical activity cannot be excluded.
The study clinics were large, central primary care clinics that serve large areas of the Bedouin and Jewish cities, so the clinic attendees were representative of the two populations in socio-economic terms. Another possible bias is information bias of the recall bias type, which is common in interview-based studies regarding the diagnosis of OAK and other baseline characteristics of the participants.
CONCLUSION
The results of this study support and expand the findings of the few prior published reports demonstrating an inverse association between traditional prayer (Namaz) and OAK. Two primary factors that could affect the natural course of OAK are weight loss and physical activity such as regular walking. The findings on high BMI in both groups and low physical activity, especially among the Bedouins, can help focus efforts of health care provides to address these risk factors with the aim of improving OAK morbidity.
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