Shoulder Complex Motion and Coordination Impairments, and the Associated Clinical Factors in Women with a History of Breast Cancer Treatment
Authors:   , Spinelli Bryan A. , Ebaugh Duane David 
Published: July 2021

Common medical management for breast cancer (BC) most often includes lumpectomy and radiation (LR) or mastectomy and reconstruction (MR). Due to these procedures involving the shoulder, it is not surprising that some women experience shoulder complex motion and coordination problems. However, the long-term effect that BC treatments have on shoulder complex motion and coordination during functional tasks is not well understood. The rationale for impaired shoulder complex motion and coordination among women with BC is that these women frequently experience impairments that are believed to contribute to these problems including soft tissue pain, decreased shoulder complex muscle strength, decreased tissue flexibility, altered resting scapular alignment (RSA), and lymphedema. However, limited research exists to support this notion. Therefore, the aims of this dissertation were 1) determine the effect that breast cancer treatments (LR and MR) have on shoulder complex motion and coordination, 2) identify clinical factors associated with impaired shoulder complex coordination in women with a history of breast cancer treatment. Scapular and humeral kinematic data and clinical measures of pain, RSA, tissue flexibility, strength and lymphedema were collected on 30 women with BC (mean age ± SD = 53.8 ± 10.9 yrs.) and 30 women without BC (mean age ± SD = 52.7 ± 10.8 yrs.). Separate one-way multivariate analysis of variance (MANOVA) were conducted to determine whether differences in shoulder complex motion existed between groups (p < .05). Angle-angle and relative motion graphs were created for 3 scapular and 2 clavicular rotations. Mean curves with 95% minimal detectable change bands (MDCB) were calculated using data from women without BC. Each woman with BC's curve was individually compared to the mean curve and MDCB. Women with BC were classified as having normal (curve fell within MDCB) or impaired shoulder complex coordination (curve fell outside MDCB). Discriminant analyses were used to identify clinical variables that could classify women as having normal or impaired shoulder complex coordination (p < .05). There were no significant differences in shoulder complex motion between women with and without BC or between those with different medical management (LR, MR). Over 93% of women with BC demonstrated impaired shoulder complex coordination for at least 1 scapular or clavicular rotation. Discriminant analysis revealed that clinical measures of pain, RSA, tissue flexibility, strength, and lymphedema were associated with impaired shoulder complex coordination. Cross-validated classification showed that 43.4% to 73.3% of women were grouped correctly. Failure to find group differences in motion may be due to the fact that women in our study were relatively high functioning and recovered from their medical management. Additionally, the majority of women in our study were previously educated on a home exercise program (73.3%) and attended physical therapy (56.7%). A lack of significant differences in shoulder complex motion between women with and without a BC suggests that the women in our study had sufficient range of motion to accomplish the functional tasks. Although we did not find differences in motion between women with and without BC across functional tasks, the majority women with BC demonstrated impaired shoulder complex coordination. Clinical measures of tissue flexibility (ROM and pectoralis minor length) were associated with impaired shoulder complex coordination across multiple scapular and clavicular rotations.