EFFECTS OF BREAST CANCER-RELATED LYMPHEDEMA ON SHOULDER MOMENT GENERATION: A MODEL BASED ANALYSIS
Restricted (Penn State Only)
- Author:
- Khatri, Ashutosh Anand
- Graduate Program:
- Biomedical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 14, 2023
- Committee Members:
- Meghan Vidt, Thesis Advisor/Co-Advisor
Spencer Szczesny, Committee Member
Daniel Hayes, Program Head/Chair
Matt Parkinson, Committee Member - Keywords:
- Lymphedema
Biomechanics
WISER Trial
ANSUR2
BCRL
Shoulder Moment
Shoulder Injuries
OpenSim
joint mechanics - Abstract:
- Breast cancer is a leading type of cancer in the United States with approximately 290,000 patients annually, out of which 287,000 patients are female [1]. About 20% of all breast cancer patients are diagnosed with lymphedema, which is a common sequel of surgery [1]. Lymphedema is a chronic condition that is typically managed using different methods of care, including manual lymphatic drainage [2], or exercise, like resistance training [3]. Resistance training has been shown to be effective at stopping the progression of lymphedema, and in some cases has reduced the severity of lymphedema [4]. Clinical trials have been carried out for several years to understand the effect of resistance training on patients with lymphedema, but none of the trials have evaluated the effects of lymphedema on shoulder biomechanics. This research studies the effects of lymphedema on the shoulder and how the moment generated at the joint, which are an indicator of possible injury exposure, change with lymphedema severity. This project used anthropometrics and body composition data from a prior clinical trial of breast cancer survivors [5]. Our research was interested in understanding the moment generated at the shoulder in three degrees of freedom. We calculated the moment using a model-based approach [6], a SolidWorks model was developed to determine the center of mass (COM) location for unaffected and affected arms, including all grades of lymphedema severity. The SolidWorks model was a composite of bone, lean, and fat mass derived from assessments of body composition. The length and circumference of arm segments were derived from anthropometric regression models. Segment length and COM locations were incorporated into an upper extremity model in OpenSim software (“MoBL Arms” [6]; software v.3.3). Separate models were developed for mean measures for all four-lymphedema severity for affected and unaffected arms. Shoulder moment was calculated for three degrees of freedom using the Inverse Dynamics (ID) tool in OpenSim for a variety of arm postures. Each posture was represented by a combination of shoulder elevation angle, elevation angle, and shoulder rotation angle. A total of seven postures were examined in each of the four lymphedema severity models with affected and unaffected arms, for a total of 128 simulations. The comparison between the moment generated at the shoulder for the affected and unaffected arm was plotted. Results showed that there is on average an 11% change in the magnitude of moment generated for the affected side in comparison to the unaffected side across different postures. It also showed an increase in muscle activation for the Deltoid and Teres major and Teres minor muscles and a decrease in activation for the Pectoralis major group of muscles. This increase in moment generated could contribute to increased loads of the soft tissues crossing the joint. Shoulder injuries are common in breast cancer survivors and this work suggests that breast cancer-related lymphedema (BCRL) may also contribute to increased exposure to injuries such as rotator cuff tears, supraspinatus tears, or tenosynovitis. In conclusion, increased lymphedema severity increases shoulder moment and may contribute to the increased incidence of shoulder injuries for breast cancer survivors.