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

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) questionnaire 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). CONCLUSION: BCS showed a reduced forearm muscle activity. BCS also presented a poor correlation between forearm muscle activity and handgrip strength. Both outcomes tended to lower values with higher levels of CRF, while preserving a good upper limb functionality.

The Benefits of a Therapeutic Exercise and Educational Intervention Program on Central Sensitization Symptoms and Pain-Related Fear Avoidance in Breast Cancer Survivors.

BACKGROUND: Central sensitization symptoms and pain-related fear avoidance are two common problems in breast cancer survivors. Non-pharmacologic interventions such as therapeutic exercise and patient education can be effective in this population. AIMS: This study aimed to: (1) analyze the benefits of a therapeutic exercise and educational program on central sensitization symptoms and pain-related fear avoidance in breast cancer survivors, and (2) explore the association between pain-related fear avoidance and central sensitization symptoms. DESIGN: A single group pre-post intervention study was conducted. METHODS: Patients were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). The intervention consisted of a therapeutic exercise and educational program that lasted 12 weeks, twice a week, for 1 hour. Two instruments were used: the Spanish version of the Central Sensitization Inventory and the Spanish Fear Avoidance Components Scale. RESULTS: A total of 82 breast cancer survivors participated in the study. Pre-post change on Central Sensitization Inventory was statistically significant (p = .007). There was a trend towards a significant difference for the Spanish Fear Avoidance Components Scale (p = .062). There was a statistically significant correlation between pain-related fear avoidance and central sensitization symptoms (r = 0.536, p < .001). CONCLUSIONS: The current study has provided preliminary evidence on the benefits of this intervention in pain-related fear avoidance and central sensitization symptoms in breast cancer survivors. The Spanish version of the Central Sensitization Inventory and the Spanish Fear Avoidance Components Scale demonstrated responsiveness to change.