Related Experiment Video
Updated: Aug 23, 2026
Using Gold-standard Gait Analysis Methods to Assess Experience Effects on Lower-limb Mechanics During Moderate High-heeled Jogging and Running
Published on: September 14, 2017
Effect of bracing on patellofemoral joint stress while ascending and descending stairs
Christopher M Powers1, Samuel R Ward, Yu-Jen Chen
1Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089-9006, USA. powers@usc.edu
Objective:
To test the hypothesis that individuals who respond favorably to bracing will exhibit decreased patellofemoral joint stress during stair ambulation.
Design:
A repeated-measures, cross-sectional study.
Background:
Ascending and descending stairs is one of the most painful activities of daily living for persons with patellofemoral pain (PFP). Although patellar bracing has been shown to reduce symptoms during such tasks, the underlying mechanism has not been identified.
Methods:
Fifteen subjects with a diagnosis of PFP completed 2 phases of data collection: (1) magnetic resonance imaging to determine patellofemoral joint contact area, and (2) gait analysis during stair ascent and descent. Data were obtained under braced and non-braced conditions. Variables obtained from both data collection sessions were used as input variables into a biomechanical model to quantify patellofemoral joint stress.
Results:
Although subjects reported an average decrease in pain of 56%, bracing did not reduce peak stress during stair ascent and descent. This finding can be explained by the fact that despite improvements in contact area, bracing resulted in greater knee extensor muscle moments and joint reaction forces.
Conclusions:
Our results do not support the hypothesis that individuals with PFP would demonstrate reduced patellofemoral stress during stair ambulation following the application of a patellar brace.
Clinical Relevance:
Although bracing did not decrease patellofemoral joint stress during stair ascent and descent, the decrease in pain, increase in quadriceps utilization, and tolerance of joint reaction forces would appear to be beneficial consequences of bracing.
Related Concept Videos
01:16Bones of the Lower Limb: Femur and Patella
01:23Stresses under Combined Loadings
The process begins by slicing the tube at critical points and analyzing the internal forces and stress components at these sections, focusing on the centroid. Normal stresses, generated by axial forces and bending moments, are either compressive or tensile and vary across the section from...
01:26Exercise Stress Test
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes
01:22Bearing Stress
Due to the intricacy of these microforces, an average value, known as bearing stress, is often used by...