Forearm Muscle Activity During the Handgrip Test in Breast Cancer Survivors: A Cross-Sectional Study

Abstract

We recruited 102 breast cancer survivors at a secondary care in Malaga. Included breast cancer survivors showed a good upper limb functionality but a reduced forearm muscle activity. Forearm muscle activity showed a poor significant correlation with the cancer-related fatigue . Handgrip strength also showed a poor correlation with the upper limb functionality. Both outcomes tended to lower values with higher levels of cancer-related fatigue. Introduction/Background: Breast cancer survivors (BCS) frequently show upper limb dysfunctions. The forearm muscle activity measured by surface electromyography (sEMG) in this population has not been studied. This study aimed to describe forearm muscle activity in BCS, as well as to assess its possible relationship with other variables related to upper limb functionality and cancer-related fatigue (CRF). Materials and Methods: A cross-sectional study was carried out including 102 BCS as volunteers at a secondary care in Malaga, Spain. BCS were included if they were aged between 32 and 70 years old, without evidence of cancer recurrence at the time of recruitment. The forearm muscle activity (microvolts, μV) was assessed by sEMG during the handgrip test. The handgrip strength was assessed by dynamometry (kg), the upper limb functionality (%) was measured by the upper limb functional index (ULFI) question- naire and the CRF was also assessed by revised Piper Fatigue Scale (0-10 points). Results: BCS reported reduced forearm muscle activity (287.88 μV) and reduced handgrip strength (21.31 Kg), a good upper limb functionality (68.85%), and a moderate cancer-related fatigue (4.74). Forearm muscle activity showed a poor significant correlation (r = –0.223, P = .038) with the CRF. Handgrip strength showed a poor correlation with the upper limb functionality (r = 0.387, P < .001) and age (r=-0.200, P = .047)...