Tai Chi for Reducing Aromatase Inhibitor-Induced Arthralgia

Inclusion Criteria:

-Individuals must meet all the following inclusion criteria in order to be eligible to participate in the study:

* Age ≥18 years
* Diagnosis of stage I-III hormone receptor-positive breast cancer
* Postmenopausal
* Currently receiving an aromatase inhibitor (anastrozole, letrozole, or exemestane) or within 5 years of initiation
* Report joint pain that started or worsened after initiation of AI therapy
* Report worst pain in the past week ≥3 on the BPI (0-10 scale)
* Able to complete study procedures in English
* Willing to be randomized to an intervention or attention control group and adhere to study procedures

Exclusion Criteria:

-An individual who meets any of the following criteria will be excluded from participation in this study:

* Undergoing active cancer treatment (excluding endocrine therapy)
* Uncontrolled cardiac or pulmonary disease that would limit safe participation
* Currently engaged in regular structured moderate- or vigorous-intensity exercise (e.g., brisk walking, jogging/running, cycling, swimming, aerobic classes, or resistance training) totaling ≥150 minutes per week over the past 3 months
* Currently participating in Tai Chi, yoga, Pilates, or other structured mind-body practice ≥2 times per week over the past 3 months
* Joint pain due to inflammatory arthritic conditions
* Recent surgery or joint injection within the past 4-6 weeks
* Initiation or dose change of corticosteroids or opioids within the past 4 weeks
* Planned discontinuation of AI therapy within the next 6 months
* This study is limited to women with breast cancer, as \<1% of cases occur in men and data on AIIA in male patients are limited