Date of Completion
ergonomics, workplace design, human factors, anthropometry, upper extremity kinematics, center of gravity, touchscreen tasks, sEMG
Donald R. Peterson
Martin G. Cherniack
John C. Bennett
Lindsay J. DiStefano
Pouran D. Faghri
Field of Study
Doctor of Philosophy
The Office of Naval Research (ONR) is interested in studying the biomechanics of upper extremity movement in a non-sea state environment. In this work, efforts to understand goal directed motor movement efficiency in the context of human performance is vital in modeling and predicting potential outcomes to shipboard naval damage control procedures, which becomes of particular importance with the introduction of women (who are of smaller anthropometries) on maritime vessels. This dissertation directly supports this Navy initiative and provides further insight into measuring goal directed end-effector (i.e., fingertip) biomechanics from an anthropometric perspective. The two objectives of this dissertation were to: 1) create a simple technique to quantify biomechanical information in an upper extremity goal directed movement task, and 2) validate the technique by assessing upper extremity movement patterns of right-hand dominant participants with respect to anthropometry. These objectives were accomplished by focusing on the kinematic analyses of study participants executing a goal-directed touching task on a touch-sensitive flat screen monitor. Upper extremity movements were measured, in-addition to, surface electromyography, and postural adjustments as a result of displacements in center of gravity (CoG). Additionally, the measurement technique in this dissertation uses motor control and anthropometric adaptation through learning as a means to exploit movement efficiency in performing a simple closed loop goal directed end-effector movement in an open and constrained space.
The results for 10 subjects show little variation in terminal touch points on the touchscreen; however, clear differences in angular displacement statistics were observed between subjects with anthropometric measurements greater than the 50th percentile male and those less than the 50th percentile male. Additionally, when participants were separated by gender, there were statistical differences between the genders in the open and constrained scenario performance across: kinematics, MVC, power spectral density, and total CoG displacement. As a result, design integration cannot be based on one singular dimension, which is commonly stature. The consideration needs to be based on the multi-dimensionality of the human physique. In the case of a goal directed pointing movement, arm length and shoulder breadth, in addition to stature, should be considered.
The true benefit of this method is that it can be ported to a maritime vessel and in-situ sea-state analysis can be conducted to compare and contrast the biomechanical adaptations that may occur. Results from this dissertation, coupled with the ONR research, will directly support a broader ONR initiative known as STAMPS (i.e., Simulation Toolset for Analysis of Mission, Personnel & Systems). The overarching goal of STAMPS is to simulate the major design of Naval vessels and the associated manpower and related cost variables, in order to model and optimize the trade spaces and human performance in platform design. The broad STAMPS initiative includes the development of detailed analysis tools, such as those presented in this dissertation, which will provide Navy decision makers with the information required to optimize and balance system and manning performance, as well as accurately predict total life-cycle costs.
The technique herein can be expanded to comparing both upper-extremities in a sea state environment. Furthermore, the technique can focus more on reaction time assessments if the need exists. The technique developed can not only assess design with respect to anthropometry, but the technique can be leveraged by clinicians for retraining the upper extremity after surgery. A pointing task is a simple movement that addresses an intent by the participant to move to a target. Pointing is a precursor to a more complex task like grasping, thus the technique herein can retrain a fundamental principal of movement. Lastly, the technique developed can also be expanded to upper extremity prosthetic assessments. The data yielded by the method provides a holistic view of an upper extremity movement. A comparison between a natural upper extremity and prosthetic upper extremity in a fundamental movement, such a pointing task, can aid clinicians in fine tuning the parameters necessary for more efficient human performance.
Deleon-Nwaha, Tanimu, "Investigating Differences in the Biomechanics of Goal Directed Movements of the Upper Extremity" (2017). Doctoral Dissertations. 1452.
APPENDIX A - Pre- and Post-Survey Questionnaires
APPENDIX B - Experimental Protocol.pdf (355 kB)
APPENDIX B - Experimental Protocol
APPENDIX C Participant Tables of Results.pdf (977 kB)
APPENDIX C - Participant Tables of Results