Energy consumption in static muscle contraction

Energy consumption during static contraction of the human triceps surae muscles was studied in 11 healthy subjects. The subjects had to stand intermittently on the left and then right foot at different frequencies (for periods of 15 s, 10 s or 5 s), first on the whole foot and then on the forefoot. The mean static energy consumption of all subjects was 13.4 (15) W [mean (s.d.)] at a calf muscle moment of 105 Nm. Assuming that static energy consumption (in W) is proportional to static moment (in Nm), a proportionality factor of 0.17 (0.19) s(-1) is found. Because of the limited attainable accuracy, no significant differences between endurance athletes and sprinters could be found.