Fascicle length change of the human tibialis anterior and vastus lateralis during walking.

Study Design: A single-group descriptive experimental design.

Objectives: To determine the fascicle length change in the tibialis anterior (TA) and the vastus lateralis (VL) muscles during walking.

Background: The length of the muscle fibers during isometric actions and during dynamic functional activities is affected by the compliance of the tendon and aponeurosis.