Exercise Science (B.S.)

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Faculty Mentor

Dr. Daniel Czech


The purpose of this research study was to measure pennation angles of the gastrocnemius muscle using ultrasound while the participant is in an upright position. Previously, pennation angles have been measured using ultrasound with the participant lying in the prone position. While lying in the prone position may be an easier method of obtaining an ultra-sound image as the muscle and participant are relaxed, muscle pennation angle will change during contraction, such as while standing. There were 16 participants, all college aged females, who completed testing on two separate days. Ultrasound images were taken of their gastrocnemius muscle while laying, standing neutral, and standing at plantar flexion and dorsal flexion angles - 15 degrees up, and 15 degrees down. These images were then analyzed with the ImageJ software to measure the pennation angles. The ultrasound images of laying in the prone position and standing in neutral were measured by both researchers to test reliability. As hypothesized, pennation angle measurements were reliable over a two day period while standing in an upright position. For lying in the prone position, the mean and standard deviations from the reliability of pennation angles were 9.4 ± 0.9 laterally and 12.6 ± 0.7 medially. For standing in the neutral position, the mean and standard deviation from the reliability of pennation angles were 9.5 ± 0.9 laterally and 12.3 ± 0.8 medially.