Peak pressure and contact profile during sideways falls on the hip:​ links with individual characteristics and falling configuration

Levine, I. C.; Laing, A. C.

Affiliations

¹Department of Kinesiology, University of Waterloo, Waterloo, ON

Abstract

Characterization of load distribution in the floor-pelvis contact plane during a fall may improve prediction of hip fracture risk, protective equipment design, and identification of “high-risk” falling configurations. Further, while estimation of the forces applied tothe hip during a fall can be achieved through multi-body modeling, Hertzian and volumetric contact models assume circular contact profiles. No published literature has linked falling configuration or soft tissue thickness (STT) with peak pressure or contact profile. The objective of this study was to test the hypotheses that (1) peak pressure would be greater in males and low-STT participants, as well as during fall simulation protocols (FSP: “Pelvis Release”, “Kneeling Release” and “Squat Release”) with less hip flexion; (2a) overall contact area and Harmonic 0 (mean radius) would be lower in males and low-STT participants, but similar between FSP; (2b) ) the Pelvis Release protocol would produce contact profiles most circular in shape; (3) contact profile elements would negatively correlate with peak pressure. Forty-four young, healthy participants (23 female) consented to undergo an eighteen-trial protocol. STT was measured via ultrasound. Peak pressure, contact area and ellipse descriptors were quantified at time of peak pressure. No pressure or contact profile variable differed significantly between males and females. Peak pressure ranged from 307-9992 kPa, and differed between FSP. Contact Area and Harmonic 0 were lower for lowSTT fallers, and lower during Pelvis Release. Contact profiles differed between STT-groups and FSP, and 76.1% of trials had contact profiles with eccentricity greater than 2.0. Peak pressure was negatively correlated with ellipse descriptors only during Pelvis Release. To summarize, peak pressure varied substantially only between falling configurations. However, contact profile characteristics were linked with peak pressure; unexplored individual characteristics or falling kinematics may drive these variables. Finally, contact profiles were substantially “round”, but more work should examine the sensitivity of load prediction models to more complex contact profiles.

Links

URL: http://ibrc.osu.edu/wp-content/uploads/2017/03/Levine-Laing-2017-OSUIBS.pdf

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Cited By (1)

Year	Entry
2018	Levine IC, Pretty SP, Laing AC. Modeling pelvis contact during lateral falls: multi-criteria evaluation of model performance and error source identification. In: Proceedings of the 14th Ohio State University Injury Biomechanics Symposium. May 20-22, 2018; Columbus, OH.