Methods

The present study was a quasi-experimental trial (pre- and post-test design) with a control group. The study population comprised older women aged 60-75 years with KOA who attended the Elderly Rehabilitation Center in Zanjan. Participants were screened by an orthopedic specialist according to the American College of Rheumatology (ACR) criteria and graded using the Kellgren and Lawrence scale (grade II or III). Inclusion criteria were having KOA in one or both knees, experiencing chronic knee pain in the previous three months, and no history of physiotherapy, structured exercise, or intra-articular injections in the preceding six months. Exclusion criteria included persistent absenteeism, use of nonsteroidal anti-inflammatory drugs (NSAIDs), and worsening of pain or disease symptoms during the study. Sample size calculations using G*Power software estimated a minimum of 40 participants. Participants were then randomly assigned to either the exercise or control group using a concealed allocation method. The exercise group participated in a structured 12-week BodyBalance training program, with three 60-minute sessions per week. Each session included a warm-up, main exercises focusing on core stability, balance, strength, and flexibility, followed by cool-down and meditation. The control group did not receive any exercise intervention during the study period. Isometric strength of the lower-limb muscles was measured pre- and post-intervention using a handheld dynamometer. Data were analyzed using appropriate statistical tests, including repeated-measures analysis of variance (ANOVA), with significance set at p < 0.05.

Results

BodyBalance training led to a significant improvement in lower-limb muscle strength in older women with KOA. In the intervention group, the strength of the knee and hip flexors and extensors, as well as the hip abductors, increased markedly, whereas the control group showed minimal changes. Repeated-measures analysis of variance revealed a significant time × group interaction for all variables assessed. These findings indicate that BodyBalance exercises not only enhance key lower-limb muscles but also provide clinically meaningful benefits, including improved motor performance and increased knee joint stability.

Discussion and Conclusion

The findings of this study demonstrated that BodyBalance training significantly improved lower-limb muscle strength, including the knee and hip flexors and extensors as well as the hip abductors, in older women with KOA. These results are consistent with previous mind–body exercise studies, which have reported enhancements in muscle strength and motor performance in similar patient populations [28, 31]. One of the most prominent neuromuscular impairments in individuals with KOA is the reduced strength of the muscles responsible for knee flexion and extension, particularly the quadriceps, which is associated with an increased risk of falls, functional limitations, and disability [28]. The quadriceps and hamstrings play a crucial role in maintaining knee joint stability through co-contraction patterns, and reduced strength and endurance in these muscles can lead to muscle fatigue, impaired proprioception, and diminished neuromuscular control [29, 30]. BodyBalance exercises, with their emphasis on balance, controlled weight transfer, and coordinated movements of the trunk and lower limbs, promote continuous activation of the hip and thigh muscles and enhance neuromuscular coordination. These mechanisms likely improve the recruitment of motor units and reduce muscle inhibition, thereby enhancing the strength of knee and hip flexors and extensors. The strengths of this study include its randomized controlled design, blinded assessments, and the use of standardized instruments for measuring isometric muscle strength, which together ensured the reliability of the findings. Limitations include the sample being restricted to older women, the evaluation of only isometric muscle strength, and the relatively short duration of the intervention, which may limit the generalizability of the results. In conclusion, BodyBalance exercises represent a safe, non­invasive, and effective approach for rehabilitating older adults with KOA. Future research should investigate the long-term effects of such interventions in more diverse populations and incorporate broader assessments of functional outcomes and quality of life.

Ethical Considerations

This study was approved by the Research Ethics Committee of Bu-Ali Sina University under the code IR.BASU.REC.1401.022 and registered in the Iranian Registry of Clinical Trials with the code IRCT20230101057015N1.

Funding

There is no funding support.

Authors’ Contribution

In the present study, data collection and the initial drafting of the manuscript were carried out by the First Author. Ideation, conceptualization, data analysis, and manuscript editing were conducted by the Second Author. The Third Author also contributed to ideation and manuscript editing. Each author reviewed and approved the final manuscript, agreeing on all aspects of the work.

Conflict of Interest

Authors declared no conflict of interest.

Acknowledgments

The authors wish to express their sincere gratitude to all the elderly participants at the Bunian Pak and Mehregan Elderly Rehabilitation and Educational Centers, as well as all individuals who assisted in the successful completion of this study.