Available at: https://digitalcommons.calpoly.edu/theses/3042
Date of Award
6-2025
Degree Name
MS in Biomedical Engineering
Department/Program
Biomedical Engineering
College
College of Engineering
Advisor
Scott Hazelwood
Advisor Department
Biomedical Engineering
Advisor College
College of Engineering
Abstract
The Tiwanaku civilization (AD 500-1100) of the Andean highlands exhibited occupational specialization in communities, with archeological evidence suggesting the existence of labor- and residential-communities, or “taskscapes”, based on an individual’s livelihood. Prior bioarcheological studies have examined Tiwanaku skeletal remains for musculoskeletal stress markers, osteoarthritis, and cross-sectional geometry to infer activity patterns. Their descendants, the Aymara Indigenous people, currently live in the same highlands and until recently lived a lifestyle like their ancestors. Over the past 20 years, the global quinoa demand has risen, thrusting the Aymara into globalization and moving them away from the traditional tasks previously performed. This study integrates biomechanics with archeological discovery by combining analysis of motion capture data from modern Aymara individuals performing traditional ancestral tasks (ceramic pottery, grain grinding, farming, chuño preparation) with skeletal indicators of activity from the Tiwanaku remains at entheses locations.
Motion capture data were analyzed in OpenSim to estimate muscle activation and forces in an upper-body model of the Aymara performing traditional tasks. Resulting muscle usage patterns were compared to documented entheseal changes in Tiwanaku skeletal remains, particularly from a site called Ch’iji Jawira, a presumed ceramicist taskscape. Results showed high activation in shoulder muscles (e.g. teres minor, infraspinatus) across multiple tasks, suggesting some of these muscles may be highly used in many traditional tasks. Muscles with more task-specific activation, such as the anconeus being only highly activated with high force for grain grinding, may offer better comparison with documented entheses. Muscle RMS activation and RMS % MVC had similar results when they were compared to entheseal alterations. The two muscles with the highest activity in the model, the teres minor and infraspinatus, did not have entheseal changes in any of the three remains of the Ch’iji Jawira individuals, but many muscles with medium or low activation did have changes. The muscle with the highest RMS force, the triceps did not have an available entheses site on any of the three individuals, but many of the muscles with the highest RMS forces did see entheseal alterations. This seeming variability in results found between the muscles with highest activity and the entheseal changes in examined individuals may be possibly due to social status differences or variations in task execution among the Tiwanaku individuals.
This proof-of-concept approach demonstrates the utility of combining biomechanics musculoskeletal modeling with archaeological indicators of activity from skeletal remains to refine interpretations of ancient labor patterns. This study also contributes to the cultural preservation of the Aymara Indigenous people by digitally documenting their traditional labor movements. Future work utilizing this framework could incorporate external load data, increased marker numbers, a full-body model, and further research into the best biomechanical output for comparison with indicators on skeletal remains to further analyze traditional Aymara movement.