Stefanie Elgaard
Pronouns:
Research Mentor(s): David Lipps
Research Mentor School/College/Department: Movement Science / Kinesiology
Program:
Authors: Stefanie Elgaard, Susann Wolfram, David Lipps
Session: Session 2: 10:00 am – 10:50 am
Poster: 28
Abstract
This study focused on muscle activity of the pectoralis major after radiation therapy for breast cancer. Specifically, we strove to understand how active the pectoralis major is during submaximal shoulder flexion and adduction contractions. The purpose of this project was to examine how the pectoralis major muscle activity is impacted during the specified muscle contractions in women who received radiation therapy for breast cancer compared to healthy controls. There were 3 groups, each with 11 participants. Two groups were managed for breast cancer with a lumpectomy, followed by radiation to the breast only or with radiation to the breast and axilla. The third group were age-matched cancer-free controls. The affected side was examined in the treatment groups, whereas the shoulder was randomly chosen for healthy participants. Each participant sat with their examined arm supported with their shoulder abducted 90 degrees at their side. An electromyographic (EMG) electrode was attached over the clavicular and sternocostal heads of the pectoralis major. EMG activity was recorded during shoulder flexion and adduction at 15% and 30% of each participant’s maximum contraction level. We hypothesized that muscle activity in the pectoralis major is decreased after radiation therapy, with the lowest activity in the breast+axilla group, followed by the breast-only group, and the highest activity in the healthy controls. Our findings disproved our hypothesis, with the most activation in the breast+axilla group and the least in the control. This research can help inform patients about their muscle health, and help surgeons/therapists design rehabilitation programs curated for a patient’s needs based on the type of radiation therapy they received.
