Breast cancer is the most commonly diagnosed cancer worldwide, accounting for 12% of all new cancer cases annually, and there were an estimated 2.3 million new cases worldwide in 2020. Contemporary breast cancer treatments have improved therapeutic outcomes. However, these treatments cause adverse effects; for example, more than half of women with breast cancer experience treatment-related comorbidities.

Over 60% of women with breast cancer have reported experiencing ipsilateral upper limb complications immediately post-treatment and these complications may become chronic or permanent disorders. Upper limb dysfunction is a long-term complication that comprises a complex range of symptoms and disorders, including lymphedema, pain, decreased joint mobility and muscle strength, sensory alterations, and neuropathies. Another prevalent and persistent problem that has been reported is sleep disturbance. According to a recent review, the prevalence of sleep disturbance ranged from 14 to 90% \[pooled estimated 0.4; 95% Confidence Interval (CI) 0.29 to 0.52\], and the persistence rate has been found to be more than 50%. Such side effects may lead to individual suffering and economic burdens, and can compromise the quality of life of women with breast cancer. Thus, the management of treatment-related side effects is an important part of the supportive care of women with breast cancer.

Yoga is based on ancient India philosophy, and emphasizes the integration of postures, breathing, and meditation. This mind-body practice has gained popularity over the last decades and serves as a complementary approach that is commonly used for various health conditions. This safe and trendy exercise holds attractive to female target participants. Yoga combines joint movements and breathing exercises that can help the lungs to expand, resulting in the stretching of muscles and thus increasing lymphatic circulation, which improves upper limb function. Besides, Yoga combines physical activity with mindful elements consisting of breathing and meditative practices. The practice of such mindfulness with the engagement of skeletal muscles represents a holistic approach that may decrease sleep disturbance.

Upper limb complications and sleep disturbances are prevalent, persistent, and serious health problems in women with breast cancer. However, these problems are underrecognized in clinical practice and thus have substantial adverse impacts on the health and quality of life of women with breast cancer. As yoga practices have been shown to improve physical and psychological health in people with cancer, such practices may also alleviate upper limb complications and sleep disturbances in women with breast cancer. However, there are few evidence-based guidelines or protocols to support the integration of yoga therapy into clinical practice for managing the health conditions of women with breast cancer. Therefore, this study aims to investigate the effects of yoga therapy on improving the upper limb functions, sleep quality, and quality of life in women with breast cancer. The research hypothesis of this study were (1) improvements in upper limb functions and sleep quality, could be observed in the experimental group across the assessment time points and (2) the experimental group should have better upper limb performance and sleep parameters than the control group immediately after Yoga intervention and also at the follow up.