Force clamp and electrical stimulation on decapod appendages

The musculature of the decapods allows for a wide variety of motion given the limited degrees of freedom of motion granted. This study focuses on a single degree of motion of a single leg segment of the crab (Menippe mercenaria) in response to electrical stimulation. A microprocessor was programmed to trigger an electrical stimulator and to provide force and length controls of the induced contraction. Digital feedback control algorithms were implemented on the microprocessor in conjunction with the Aurora Dual Mode Lever System to provide force clamp, length clamp, as well as other loading conditions. The resulting experiment setting provides a useful platform for studying the mechanics of muscle contractions.