Effect of glenohumeral forward flexion on upper limb myoelectric activity during simulated mills manipulation; relations to peripheral nerve biomechanics

Protective myoelectric activity at performing upper limb neurodynamic test 1 in breast cancer survivors. A cross-sectional observational study

Myoelectric activity and range of motion during ULNT1 were recorded in 62 breast cancer (BC) survivors who had axillary lymph node dissection (n = 30) or sentinel lymph node biopsy (n = 32) within the previous 18 months, and 63 age-matched healthy women. BC survivors' symptoms were reproduced by ULNT1 and exhibited greater myoelectric activity in the biceps brachii than healthy women (MD (95% CI): 21,26 (10,83-31,70)). No differences between the axillary lymph node dissection and sentinel lymph node biopsy groups (MD (95% CI): 8,47 (-7,84-24,79)) were found. Myoelectric activity in the triceps brachii was greater in the sentinel lymph node biopsy group (MD (95% CI): 2,70 (-2,06-7,60)). BC survivors exhibited less shoulder and elbow range of motion during ULNT1 than healthy women. Increased upper limb nerve mechanosensitivity in BC survivors was associated with a greater protective muscle response during ULNT1.