INTRODUCTION: Post-surgical immobility associated with mastectomy may present significant challenges to the individual’s muscular strength, endurance and overall quality of life. The Disability of the Arm, Shoulder, and Hand (DASH) and PENN Shoulder Scale (PSS) are administered to quantify shoulder restrictions and symptomology reported by the patient.
PURPOSE & HYPOTHESIS: To examine effectiveness of utilizing DASH and PSS in predicting upper extremity estimated one repetition maximum (E1RM) strength in sedentary breast cancer survivors (BCS). We hypothesized a strong positive correlation between increased affected limb disability and decreased upper extremity E1RM.
METHODS: Twenty-eight BCS (aged 53.6 ± 9.73 years) were recruited from Los Angeles County Hospital and Norris Comprehensive Cancer Center at USC as a part of a larger ongoing exercise intervention study. Participants reported to the Women’s Health and Exercise Laboratory at the University of Southern California and completed DASH and PSS questionnaires followed by a 10-Repetition Maximum (10-RM) muscular strength test for chest press (CP) and latissimus pull-down (LPD). Investigators calculated E1RM from measured 10-RM values. Statistical analyses included a Pearson Correlation and regression analyses to compare scores with E1RM. Statistical significance was set at p< 0.05.
RESULTS: Mean (± SD) PSS and DASH shoulder scores were reported at 73.6 ± 19.0 out of 100 total points and 18.9 ± 16.0 out of 30 total points, respectively. Mean E1RM from CP was 5.7 ± 4.2 kg and 27.7 ± 10.9 kg from LPD. Higher DASH scores were not correlated with lower E1RM of CP or LPD (p = 0.20; p= 0.64, respectively). There were no statistically significant correlations when comparing PSS with E1RM in both CP and LPD upper-body exercises (p=0.71, p=0.26, respectively). Regression analyses showed no relationship with higher DASH or PSS scores and lower E1RM from CP and LPD (r2= 0.007).
CONCLUSION: The DASH and PSS assessments of shoulder disability were not related to E1RM of CP or LPD in sedentary BCS. While DASH and PSS assessments may not be appropriate assessment tools for predicting upper body strength in BCS, these assessments may be further explored in predicting functional upper body outcome measures, such as hand grip strength. Supported by NIH/NCI KO7CA160718.