Extended Abstract
1.    Introduction
Genu varum is a common skeletal deformity that can contribute to both acute and chronic lower limb injuries. Due to the altered alignment between the femur and tibia, individuals with genu varum experience abnormal distribution of intercondylar forces. This biomechanical imbalance is particularly pronounced during landing tasks, where ground reaction forces (GRFs) can reach several times the individual's body weight (1, 2). Jumping and landing are fundamental components of many athletic activities, and improper joint alignment during these movements can increase the risk of injury. Toe orientation—specifically toe-in and toe-out positions—has been shown to influence lower limb kinematics and is frequently considered in both performance optimization and rehabilitation strategies (13–15). In the context of osteoarthritis, which is a progressive and currently incurable condition, foot orientation strategies have been explored as a means to reduce medial knee loading by minimizing knee adduction torque during gait (16). Given that individuals with genu varum already experience increased pressure on the medial compartment of the knee, modulating toe orientation during high-impact movements such as landing could offer a useful biomechanical intervention. Altering knee adduction torque through changes in toe position may help redistribute forces more evenly across the joint, thereby providing both preventive and rehabilitative benefits (18–20). Therefore, the present study aimed to investigate the effects of toe-in and toe-out orientations during landing on knee adduction torque in young men with genu varum, in order to explore potential strategies for reducing medial knee compartment loading in this population. 
2.    Methods
This quasi-experimental study followed a pre-test–post-test design and was approved by the Ethics Committee of the Islamic Azad University, East Tehran Branch (IR.IAU.ET.REC.1400.025). Participants were selected from male students at Kharazmi University, aged between 22 and 36 years, who expressed willingness to participate in the study. Based on the inclusion criteria, 14 individuals with genu varum were recruited as the final sample. Eligibility criteria included appropriate age range and presence of genu varum, with exclusion criteria comprising any history of traumatic injury, lower limb fractures, musculoskeletal disorders of the lower limbs or spine, knee osteoarthritis, respiratory conditions, neurological impairments, and other musculoskeletal diseases. All participants signed informed consent forms confirming their eligibility and willingness to participate. Participants attended the biomechanics laboratory and performed a drop landing task under two toe orientation conditions: (1) toe-in and (2) toe-out. Each participant completed three successful trials per condition, which were recorded for analysis. Kinematic and kinetic data were captured using a high-speed camera and a force plate, and all recordings were processed using MATLAB software. Descriptive statistics (mean and standard deviation) were calculated for the target variables. The Shapiro–Wilk test was used to assess the normality of the data, and paired t-tests were conducted to compare the biomechanical variables between the two toe conditions. Statistical analyses were performed using SPSS version 23, with the significance level set at p ≤ 0.05.

3.    Results
The analysis of knee adduction torque during the landing phase revealed that torque values were significantly higher in the toe-in condition compared to the toe-out condition. Paired t-test results indicated a statistically significant difference in mean knee adduction torque between the two toe orientations (p = 0.001), with the toe-in strategy producing greater torque than the toe-out strategy (Fig. 1). 

4.    Discussion
This study examined the effect of toe-in and toe-out landing strategies on medial knee compartment pressure in individuals with genu varum. The results demonstrated that a toe-out landing strategy significantly reduces knee adduction torque compared to the toe-in strategy. Previous studies have explored various movement strategies and their association with acute and chronic injuries. One of the most frequently investigated topics has been knee alignment—specifically valgus and varus orientations—during landing, as proper alignment can help reduce injury risk (23). Toe angle has also been identified as a key factor influencing lower limb biomechanics. For instance, Andrews et al. (1996) found that individuals with a greater toe-out angle during the double-support phase of walking exhibited significantly reduced knee adduction torque—findings that are consistent with the present study (30). Similarly, Goe et al. (2007) reported that in individuals with medial knee osteoarthritis, an increased toe-out angle during walking and stair ascent was associated with reduced peak knee adduction torque, potentially helping to slow disease progression (31). However, the same study found no significant relationship between toe angle and adduction torque during stair descent, which contrasts with the findings of our current study (26). Toe angle can vary widely across individuals due to differences in movement habits or biomechanical adaptations. In the present study, to enhance consistency and accuracy, toe angles were standardized for all participants. In contrast, some previous research has allowed participants to self-select toe angles, potentially introducing variability in movement patterns and joint loading. It should be noted that this study was conducted in a single session, without accounting for long-term adaptations or motor learning effects, which may influence coordination patterns. Furthermore, landing tasks involve high ground reaction forces, and even subtle changes in lower limb alignment can significantly alter joint loading.
In conclusion, the findings suggest that adopting a toe-out landing strategy may be beneficial for reducing medial knee compartment pressure in individuals with genu varum, thereby potentially lowering the risk of both acute and chronic injuries. Further longitudinal and neuromuscular studies are recommended to explore the long-term effects and underlying mechanisms of this intervention strategy.

Ethical Considerations
Compliance with ethical guidelines
All ethical considerations were fully observed in this study. Participants were informed about the research procedures in detail and provided written consent prior to participation. They were also assured of their right to withdraw from the study at any time without penalty. Furthermore, all personal information was kept strictly confidential and used solely for research purposes.
Funding
This research did not receive any grants from funding agencies in the public, commercial, or non-profit sectors. 
Authors' contributions
All authors participated in the design, implementation, and writing of all parts of this research.
Conflicts of interest
The authors declare that there are no conflicts of interest associated with this article.