Abstract
Post-traumatic joint contracture (PTJC) of the elbow results in pain, stiffness, and loss of motion that can substantially impair daily function. While flexion-extension deficits in PTJC have been well characterized, the effects on pronation-supination remain poorly understood due to limited testing capability. The objective of this study was to develop and validate a method for quantifying rat elbow pronation-supination motion to better characterize elbow dysfunction. An existing load-controlled cyclic testing protocol was adapted using a rack-and-pinion system to convert linear displacement into forearm rotation, generating torque-displacement curves from which range of motion (ROM) and stiffness were evaluated. The protocol was optimized by reducing the applied force limit, increasing testing speed, and improving fixture alignment and repeatability. The updated method was validated by testing arthritis (CIA) and control (PBS) rat elbows. CIA elbows exhibited significantly greater total ROM and neutral zone length, as well as reduced stiffness compared to PBS elbows, somewhat consistent with prior findings in flexion-extension motion. These results demonstrate the effectiveness of the developed pronation-supination testing protocol and highlight the importance of evaluating multiple degrees of freedom to fully characterize elbow joint dysfunction. This method provides a critical tool for future studies investigating PTJC-induced functional deficits in the elbow.
Document Type
Final Report
Class Name
Mechanical Engineering and Material Sciences Independent Study
Language
English (en)
Date of Submission
12-15-2025
Recommended Citation
Jarrell, Genevieve, "Development and Validation of a Pronation-Supination Testing Protocol for Rat Elbow Joint Function" (2025). Mechanical Engineering and Materials Science Independent Study. 308.
https://openscholarship.wustl.edu/mems500/308