Effect of flow material ski boots on foot circulation

Abstract

The effect of modern "flow material" ski boots on foot circulation was studied. Pressure inside a flow material ski boot was found to be markedly higher than in a conventional ski boot. In some places the pressure exceeded the diastolic pressure in the foot. 113mIndium chloride, which when injected intravenously is bound to transferrin was used for blood pool scanning. In healthy young volunteers the uptake of radioactivity in the two feet--one with and one without a ski boot--was compared. The activity level of the foot with the ski boot was significantly lower than in the other foot. After corrections were made for absorption by the boot, a significant difference remained. Plethysmographic studies were performed with a mercury strain gauge using a ski boot in which a hole was cut over the big toe. No difference was demonstrated between the blood pressure at the leg just above the boot top and at the big toe. The arterial pulse wave at the big toe was altered; i.e., there was an absence of a dichrotic wave. Intramuscular perfusion was studied with 133xenon. The disappearance curve in a foot with a boot was more shallow than that in a bare foot. Unbuckling resulted in an immediate fall in radioactivity, the disappearance curve then becoming identical to that of the bare foot. The results indicate that when flow material ski boots are to be used by skiers who are not in the habit of unbuckling for short intervals, buckle tension should not be too high.