Thermal Constraints on Neural Conduction Velocity: Addressing a Systemic Omission in Avian and Insect Locomotor Biomechanics

Abstract The existing peer-reviewed literature on locomotor biomechanics in heterothermic birds and insects predominantly omits a critical variable: the instantaneous measurement of the localized operating temperature of peripheral neuromuscular tissues. While thermal physiology has long recognized the importance of muscle temperature, biomechanical models frequently fail to integrate these localized thermal states into real-time assessments of neural conduction velocity and motor coordination. This oversight renders historical kinematic data concerning control, agility, and maximum performance unreliable, as nerve signal transmission speed and muscle power output are governed by temperature-dependent kinetics. To address this, the present paper defines this missing variable and establishes three novel indices to quantify functional deficits: the Avian Pedal Neural Conduction Index (APNCI), the Avian Flight Neural Conduction Index (AFNCI), and the Insect Locomotor Neuromuscular Performance Index (ILNPI).