title: Two types of slip-induced falls among community dwelling older adults.
abstract: Little is known about the landing behavior of the trailing (recovery) foot and ensuing types of falls following a forward slip in walking. The purposes of this study were to (1) determine if community-dwelling older adults experienced bilateral slips at the same rate as had been previously observed for young adults during over-ground walking; (2) determine if fall rate in older adults was dependent on slip type (unilateral vs. bilateral); and (3) identify differences in spatiotemporal variables of the trailing leg step between unilateral and bilateral slips. One-hundred-seventy-four participants experienced an unannounced, unrehearsed slip while walking on a 7-m walkway. Each trial was monitored with a motion capture system and bilateral ground reaction force plates. Although the experimental design, developed with original data from a young adult population, favored bilateral slips, more older adults (35%) than anticipated (10% previously observed in young, p<0.001) displayed a unilateral slip. The probability of fall was equal in the two types of slips. Eighty-two people recovered from the slip, while the remaining 92 (53%) fell. These 92 were classified into two exclusive categories based on the heel distance at the time of fall arrest using cluster analysis: those which resembled a fall into a "splits" position (n=47) or a feet-forward fall (n=45). All (100%) unilateral slips led to splits falls, as expected. Yet, not all bilateral slips (only 83%) resulted in feet-forward falls. A longer forward recovery step with a prolonged step time led to both feet slipping, nearly together, hence a feet-forward fall.
authors.affiliation: Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Yang
authors.forename: Debbie
authors.initials: D
authors.lastname: Espy
authors.forename: Tanvi
authors.initials: T
authors.lastname: Bhatt
authors.forename: Yi-Chung
authors.initials: YC
authors.lastname: Pai
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001696:Biomechanical Phenomena; D016000:Cluster Analysis; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008954:Models, Biological; D004856:Postural Balance / Q000502:physiology; D014741:Video Recording; D016138:Walking / Q000502:physiology