Ultrasound is a widely used diagnostic tool for patients with plantar fasciitis. It provides an inexpensive and noninvasive method for quantifying the plantar fascia with accuracy levels comparable to magnetic resonance imaging (MRI). However, some researchers have criticized the lack of standardization in the ultrasound measurement process for plantar fascia thickness as it calls into question the validity of the final measures. One critical component lacking any standardization during the procedure is metatarsophalangeal (MTP) joint position as ultrasound examiners often extend the toe position during the process. This variation has made it difficult to understand the etiology of plantar fasciitis and to identify risk factors, such as gender. The purpose of this study was to investigate and compare the influence of MTP joint extension position on plantar fascia thickness in healthy participants and those with unilateral plantar fasciitis, as well make gender comparisons while controlling for MTP joint position. The plantar fascia thickness of forty participants (20 with unilateral plantar fasciitis and 20 control) was measured via ultrasound three times at three different MTP joint positions: 1) at rest, 2) 30 of extension from the plantar surface, and 3) maximal extension possible. The plantar fascia became significantly thinner as MTP joint extension increased in both the plantar fasciitis group (p<0.001) and the control group (p<0.001). When comparing gender differences, males in the plantar fasciitis group had a significantly thicker plantar fascia when compared to female counterparts (P=0.048). However, no significant differences were observed between healthy males and females. The results from the study highlight the need to standardize the position of the MTP joints during measurement of plantar fascia thickness. As well, healthy males and females first begin with very similar plantar fascia thickness levels. However, as the onset of plantar fasciitis develops, males tend to exhibit thicker plantar fasciae than their female counterparts.

LLU Discipline

Rehabilitation Sciences


Physical Therapy


School of Allied Health Professions

First Advisor

Lohman III, Everett B.

Second Advisor

Daher, Noha S.

Third Advisor

Gordon, Keith E.

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Fasciitis; Plantar; Ultrasonography; Ultrasonic imaging; Joints -- Examination;

Subject - Local

MTP joint position; Metatarsophalangeal joint position; Joint extension; Plantar Fascia



Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives