Trunk stiffness and stability can be related to the posture and alignment of the human body. This project continues on the evolution of the Twister, a trunk bending apparatus, that is intended to measure and acquire data of axial and torsional stiffness in core muscles. Then, postural performance can be linked to measured torso stiffness examine muscle reaction patterns with the consideration of age, height, weight, and other factors.
In the 1980's, Dr. Victor Gurfinkel, medical researcher at Oregon Health & Science University, developed the Twister to measure torsional muscle tone as well as muscular responses as the apparatus twisted the subject. The body sections considered by the Twister are the neck, trunk, and waist to Then, Dr. Gurfinkel devoted the apparatus to Dr. Rajal Cohen at University of Idaho, Psychology & Communication Studies Department, upon his retirement.
The previous team assembled and modified the structure to be relevant for the trunk bending experiments. They created an interface software to collect data, upgraded the hardware, and built harnesses. The objective is to bring the machine into an operational state by using higher quality parts, completing circuitry, making the machine more user-friendly, adding safety features, and testing and collecting data from the final product.