The relationship between elbow flexor volume and angular stiffness at the elbow.

OBJECTIVE: The purpose of this experiment was to determine if a correlation exists between the volume of the elbow flexors and angular stiffness at the elbow, and to determine the contribution of the biceps brachii and the brachialis muscles to angular stiffness. DESIGN: This study is a descriptive, correlational study and presents a graphical model of the passive properties of muscle. BACKGROUND: The correlation between arm volume and angular stiffness has been shown, but the measurement of arm volume was not specific to the structures being strained.