Change in Shoulder Function in the Early Recovery Phase after Breast Cancer Surgery: A Prospective Observational Study.

Breast cancer surgery significantly affects the shoulder's range of motion (ROM) and strength. However, the extent of shoulder impairment, as well as patterns of recovery immediately after surgery, is not fully understood. Therefore, we aimed to investigate shoulder ROM and strength during the early recovery phase after surgery. Thirty-two breast cancer patients were observed five times: the day before surgery, discharge day (postoperative day 1 (POD1) or (POD2)), first outpatient visit (POD7-10), second outpatient visit (POD14-20), and third outpatient visit (POD21-30). We assessed shoulder passive ROM and strength for both affected and unaffected arms at each observation. ROM decreased in both affected and unaffected sides post-surgery. ROM on the affected side did not recover to the pre-surgery level until the third outpatient visit (POD24). In contrast, the ROM on the unaffected side recovered to the pre-surgery level by the first outpatient visit (POD10). The shoulder strength of both arms declined and did not recover to pre-surgery levels. Shoulder strength in the affected arm significantly decreased immediately after surgery (52.9% of the pre-surgery levels) and did not recover until the third outpatient visit (62.5% of the pre-surgery levels), whereas that in the unaffected arm decreased gradually (83.1 ± 2.3 at POD 1 and 78.9 ± 2.9 at POD 24). Descriptively, patterns of recovery in ROM may vary according to types of surgery while patterns of recovery in shoulder strength did not: shoulder strength significantly decreased and did not recover notably regardless of types of surgery. Both shoulder ROM and strength reduced during the early recovery phase after breast cancer surgery regardless of types of surgery, although the degree of reduction was greater in shoulder strength than ROM. Our findings suggest that rehabilitation exercises should be implemented in both upper limbs.