Degree Type


Date of Award


Degree Name

Master of Science


Industrial and Manufacturing Systems Engineering


Industrial Engineering

First Advisor

Gary Mirka


Sonographers assume awkward postures of the upper extremities and torso while performing scanning tasks. Upper extremity exoskeletons are a potential ergonomic intervention to support sonographers in their work. This study examined the effects of a passive upper extremity exoskeleton on objective muscle activity and posture and subjective discomfort of sonographers performing transthoracic echocardiograms (TTE). Four practicing sonographers performed TTE procedures using both the right- and left- handed scanning TECHNIQUES, with and without a passive upper extremity EXOSKELETON (2x2 design). A randomized complete block design was used with participants acting as the blocking variable. At the 50th percentile of normalized muscle activity, the exoskeleton significantly reduced the right upper trapezius (p=0.045), left upper trapezius (p<0.001), and the right medial deltoid (p=0.034) activation. There was also a significant interaction between EXOSKELETON and TECHNIQUE for the right anterior deltoid (p=0.0007) and the left medial deltoid (p=0.006), though simple effects analysis revealed the exoskeleton only reduced muscle activity in left-handed scanning. At every percentile level considered, the exoskeleton tended to reduce muscle activity during left-handed scanning but had little impact on right-handed scanning. Averaged across right and left-handed scanning, the 50th percentile of posture data showed the exoskeleton significantly reduced the vertical angles of the torso (14.5 vs. 21.1 degrees), left arm (15.3 vs. 21.4 degrees), and right arm (24.4 vs. 28.4 degrees) but had no impact on head angle. However, self-reported discomfort and utility did not reflect the results from the objective measures. This study provides data to support the hypotheses that upper extremity exoskeletons have positive impacts on muscle activity and posture in sonography, but the type of work and the interaction between the sonographer and patient must be considered in order for the device to provide the greatest benefit.


Copyright Owner

Jordyn Koenig



File Format


File Size

70 pages