Cantarero-Villanueva I, Fernandez-Lao C, Diaz-Rodriguez L, Fernandez-de-las-Penas C, Ruiz JR, Arroyo-Morales M: The handgrip strength test as a measure of function in breast cancer survivors: relationship to cancer-related symptoms and physical and physiologic parameters. Am J Phys Med Rehabil 2012; 91: 774-782. Objective: The aim of this study was to examine the relationship of muscular strength, as measured by the handgrip strength (HGS) test, with pain, fitness, fatigue, mood, and autonomic nervous system function in breast cancer survivors. Design: A cross-sectional study comprising 95 breast cancer survivors was conducted. HGS; heart rate variability; pressure pain threshold of the neck, shoulder, hand, and tibia of the affected side; and fitness level (6-min walk test, neck-shoulder mobility, vertical jump, sit-to-stand test, and trunk curl test) were assessed as outcomes. Participants completed the Fatigue Piper Scale and Profile of Mood States questionnaires and the neck-shoulder visual analog scale. Correlation was conducted to examine the relationship of HGS with pain, fitness, fatigue, and mood. Results: We observed a fair relationship of HGS with shoulder pain and a moderate to fair relationship with fitness (all P < 0.01; Q range, 0.24-0.56). The relationship between HGS and heart rate variability (high-frequency domain) was weak (P = 0.049, Q = 0.23). Likewise, the relationship between HGS and Profile of Mood States subscales ranged from weak to fair (all P < 0.001; Q range, -0.22 to -0.36). HGS showed a weak relationship with Fatigue Piper Scale (all P < 0.01; Q range, -0.28 to -0.35). Passive shoulder flexion, fatigue, and vertical jump were independent and significant predictors of HGS (P < 0.01; R-2 = 0.466). Conclusions: These results suggest that the HGS test might be an important correlate of health in breast cancer survivors. This finding suggests that HGS could be recommended as an adjuvant method of evaluation, which may help with efficiency of clinical practice. Further research on breast cancer patients is needed to confirm or refute these findings.