Abstract Abstract #1124 Introduction: About half the women who undergo breast cancer surgery report consequent shoulder problems. However, their perception of symptoms such as loss of movement and strength may not be reflected in physical measurements. The aim of this study was to compare the women's perception of symptoms with objective measurements of muscle strength and range of motion (ROM). Methods: One hundred thirty two women (mean age 53 years, SD 12) with early stage breast cancer participated in this study within 6 weeks of their surgery. Participants rated their perception of shoulder ROM and strength on a 5-point likert scale, with the anchors “no impairment” (0) to extreme (4). Shoulder abduction and forward flexion muscle strength were tested using a hand-held dynamometer and ROM with a digital inclinometer. Muscle weakness was defined as a deficit > 20% compared to the unaffected side in either movement. Limited ROM was categorized as > 20° deficit compared to the unaffected side. Results: Thirty two percent of women reported minor weakness, 17% reported moderated weakness, 4% reported major weakness, and no women reported extreme weakness. In addition, 36% reported a minor limited ROM, 32% reported moderate limited ROM, 11% reported major limited ROM, and no women reported extreme limited ROM. Fifty eight percent of women had > 20% muscle weakness and 15% of women had > 20° limited ROM in either shoulder flexion or abduction. There was a moderate relationship between participants' perception and objective measurements in range of motion (Spearman's rho = 0.55 and 0.57 for abduction and flexion, respectively) and a weak relationship for muscle strength (0.28 and 0.18). Interestingly, 28 women reported having no weakness on their affected side, although, strength measurements showed > 20% weakness compared to the unaffected side. Also, 20 women showed less than 20% strength difference between arms but reported having minor to major loss of muscle strength. Conclusion: The women's perception was weakly related to the objective measurements. Physical and psychological factors may contribute to the perception of symptoms. Acknowledgement: Supported by NSW Cancer Council. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1124.