Inclined foot switches for surgical microscopes: a comfortable design for seated surgeons: technical note

During microneurosurgical procedures, surgeons sitting on a stool may experience muscular fatigue in the lower half of the body due to repeat manipulation of foot switches controlling the surgical microscope. The mechanisms contributing to this fatigue were examined and a method developed for fatigue reduction. The switch panel harboring the pedals was originally designed to be placed horizontally, but was inclined toward the surgeon with a sandbag placed under the panel. The modified panel was used in consecutive surgeries by 3 surgeons. Surface electromyographs of the bilateral gastrocnemius and gluteus maximus muscles were obtained during simulated activation of the switches on horizontal and inclined panels using the left foot. Inclined panels facilitated stepping on the pedals, required less muscle power, and lessened fatigue and hip pain. Electromyographs obtained during stepping on the switches on the horizontal panel showed contraction of the left gluteus maximus, and the right gastrocnemius and gluteus maximus, muscles that do not directly contribute to stepping, in addition to contraction of the left gastrocnemius, a main muscle in the stepping motion, i.e. flexion of the ankle. Electromyographs obtained during stepping on the switches on the inclined panel showed muscle contraction was limited to the left gastrocnemius with lower frequency and amplitude motor unit potentials compared to those elicited during use of the horizontal panel. Our simple modification facilitates operating microscope manipulation and reduces surgeon fatigue.