The goal of this clinical trial is to learn if Baduanjin exercise could be adopted by breast cancer survivors and improve their upper limb dysfunction. The main questions it aims to answer are:

• Does Baduanjin exercise improve upper limb dysfunction among breast cancer survivors?
• What problems or adverse events do participants have if they adopt Baduanjin exercise to improve upper limb dysfunction?

Participants will:

• Adopt Baduanjin exercise following an evidence-based intervention protocol
• Report their exercise frequency, length, and unexpected symptoms
• Receive three times assessment and follow-up every week

To evaluate the feasibility, acceptability, and preliminary effects of Baduanjin exercise on upper limb dysfunction (ULD), shoulder range of motion (ROM), pain, sleep quality, depression and anxiety, and quality of life (QoL) in breast cancer survivors. The objectives of this study are to:

1. Develop an evidence-based Badunajin exercise intervention protocol for managing ULD among breast cancer survivors ;
2. Design and conduct a pilot Randomised Controlled Trial (RCT) using the Buduanjin exercise intervention protocol to manage the ULD;
3. Test the feasibility and acceptability of the Baduanjin exercise intervention and RCT procedures by the recruitment rate, retention rate, and attrition rate during the pilot RCT;
4. Evaluate the safety, efficacy, and acceptability of the Baduanjin exercise intervention by identifying potential adverse effects associated with the Baduanjin exercise intervention;
5. Examine the potential effects of Baduanjin exercise intervention on ULD, shoulder ROM, pain, sleep quality, depression and anxiety, as well as QoL among breast cancer survivors;
6. Explore the participants' experience and suggestions for the Baduanjin exercise intervention and study procedures; and
7. Provide evidence for refinement of the Baduanjin exercise intervention for a multi-center, full-scale RCT among breast cancer survivors.

Inclusion Criteria:

1. Female, aged ≥ 18 years, diagnosed with non-metastatic unilateral Stage I-IIIa non-metastatic breast cancer, regardless of cancer type;
2. Surgeries completed at least two months before enrolment, and completion of radiotherapy and/or chemotherapy, with or without aromatase inhibitor therapy, upon enrolment;
3. Experiencing breast cancer treatment-related ULD, which is measured by the Disabilities of the Arm, Shoulder, and Hand (DASH) scale with a score of 20 or above;
4. Karnofsky Performance Status Scale (KPS), used to measure a patient's ability to perform daily activities and self-care independently, with a score of 90 or above;
5. Ability to read, write, and communicate in Chinese;
6. Have a personal cellphone;
7. Agree to participate in this study and provide written informed consent.

Exclusion Criteria:

1. Any patient with a history of upper limb surgery, injury (fracture or shoulder dislocation), or other conditions not related to breast cancer treatments;
2. With other complications or adverse medical conditions that cannot perform BdjE, such as severe lymphedema, axillary web syndrome, or adhesive capsulitis;
3. Undergoing any physiotherapy for ULD or leading regular physical exercises in the previous three months;
4. Had skin grafting and autologous myocutaneous flap breast reconstruction;
5. Current clinical diagnosis of depression or anxiety, or receipt of active psychological treatment for significant mood or anxiety disorders;
6. Currently involved in other clinical studies.