Study of the biodynamic response of the foot to vibration exposure

Abstract

Abstract.BACKGROUND: Exposure to foot-transmitted vibration (FTV) has been linked to injury; however, the biodynamic response of the foot to FTV has not been quantified. OBJECTIVE: The objective was to measure vibration transmissibility from the floor-to-ankle, and the floor-to-metatarsal, during exposure to FTV while standing, and to determine if FTV exposure frequency, or participant mass or arch index (AI) influence the transmission of FTV through the foot. METHODS: Participants' AI was measured. Four ADXL326, tri-axial accelerometers were utilized to measure vibration on the platform medial to distal head of first metatarsal, on the distal head of first metatarsal, on the platform paralleling the medial malleolus, and on the lateral malleolus. Participants were randomly exposed to FTV at 25 Hz, 30 Hz, 35 Hz, 40 Hz, 45 Hz, and 50 Hz for 45 seconds. CONCLUSIONS:The greatest transmissibility magnitude measured at the metatarsal and ankle occurred at 50 Hz and 25-30 Hz respectively, suggesting the formation of a local resonance at each location.

Effect of the Shoe Sole on the Vibration Transmitted from the Supporting Surface to the Feet

“…The result confirms that a different shoes compliance does not modify the apparent mass measured at the driving point [25]. Goggins and colleagues [26] also observed a difference in vibration transmissibility over a 25-50 Hz exposure frequency with the greatest magnitude of transmissibility occurring at 25-30 Hz for the ankle and 50 Hz for the first toe.…”

“…Although the participants were asked to maintain this posture for the full 51 s of the vibration exposure, we did not strictly monitor their posture, so it is possible that minor changes in posture occurred. Changes in knee angle or standing center of pressure distribution could influence the magnitude of vibration transmitted through the body [26,31]. However, participants were observed during vibration exposure and no visual deviations from their natural upright standing posture were observed.…”