Award Date


Degree Type

Doctoral Project

Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

Advisor 1

Kai-Yu Ho, PT, MSPT, Ph.D

First Committee Member

Daniel Young, Ph.D

Second Committee Member

Merrill Landers, Ph.D

Number of Pages



Purpose/Hypothesis: Reduced trunk flexion during running is theorized to be a contributing factor of elevated patellofemoral joint (PFJ) stress in runners with patellofemoral pain (PFP); thus, the primary purpose of this research study was to determine if runners with PFP would exhibit differences in PFJ stress and trunk flexion angle during running as compared to pain-free runners across three speeds. We hypothesized that runners with PFP would exhibit higher PFJ stress and decreased trunk flexion while running compared to the pain- free runners. Number of Subjects: 7 runners with PFP and 5 similar pain-free control runners. Materials/Methods: Kinematics and kinetics of the trunk and lower extremity were obtained at 3 different running conditions: self-selected, fast (10% faster than self-selected), and slow (10% slower than self-selected) speeds. PFJ stress, PFJ reaction force, and PFJ contact area were determined using a biomechanical model that utilized subject-specific input variables (i.e., knee flexion angle and knee extensor moment). A 2-way ANOVA with repeated measures was used to compare outcome variables across the 3 speeds and between the 2 groups. Results: Running speeds were similar between groups. There was no statistically significant difference in peak PFJ stress between groups across the 3 speeds (p>0.05). Additionally, no significant difference was found in trunk flexion angle, PFJ reaction force, PFJ contact area, knee extensor moment, knee flexion angle, GRF at peak stress, PFJ contact area, knee flexion angle, or trunk flexion angle between the two groups across the 3 speeds (p>0.05). Peak PFJ stress was found to be highest during fast running compared to the slow speed across both groups (p= 0.017). Conclusions: Runners with and without PFP exhibited similar peak PFJ stress and trunk flexion angle when running at slow, self-selected, and fast speeds on a treadmill.


Patellofemoral pain; Trunk flexion angle; Running; Patellofemoral joint stress


Physical Therapy

File Format


File Size

1648 KB

Degree Grantor

University of Nevada, Las Vegas