Developmental dysplasia of the hip (DDH) is a condition that involves the dislocation of the head of the femur in the acetabulum of the pelvic bone. Although it may not interfere with a child's range of motion during infancy, DDH can cause various effects over time such as joint pain, abnormal gait, and even paralysis. It is crucial to catch this phenomenon early on so that permanent disability is not introduced to the patient. In this study, an excitation device was used to send a broadband frequency signal through a hip joint simulated by a 3D printed bone apparatus consisting of a left femur and left pelvic bone. Accelerometers were used to sense the transmission of this signal through the bones tested. Variability was induced through different experiments in order to determine where the optimal frequency for detection of DDH would be. After variability was quantified for all of the nonconsecutive and consecutive trials, the excitation device was tested on a raw chicken quarter through the knee joint since this was very similar to the hip joint. Coherence, phase, and transfer function graphs were used to demonstrate the degree of variability, optimal frequencies for detection, and degree of signal transmission through the joints tested. The results from the 3D printed bone model showed that the height of accelerometer suspension, loosened coupling of sensors, and vertical alignment of the bone model apparatus affected the transfer function and phase graphs of the experiments while coherence stayed relatively the same. On the other hand, the results from the raw chicken model displayed similarities between graphs for little to no joint dislocation but the complete dislocation of the bone yielded significantly different graphs.

Thesis Completion




Thesis Chair/Advisor

Mansy, Hansen


Bachelor of Science (B.S.)


College of Medicine


Burnett School of Biomedical Sciences

Degree Program

Biomedical Sciences



Access Status

Open Access

Release Date