Hip impact velocities and body configurations for voluntary falls from standing height.
J Biomech
; 29(6): 807-11, 1996 Jun.
Article
en En
| MEDLINE
| ID: mdl-9147979
ABSTRACT
Fall dynamics have largely been ignored in the study of hip fracture etiology and in the development of hip fracture prevention strategies. In this study, we asked the following questions (1) What are the ranges of hip impact velocities associated with a sideways fall from standing height? (2) What are the ranges of body configurations at impact? and (3) How do protective reflexes such as muscle activation or using an outstretched hand influence fall kinematics? To answer these questions, we recruited six young healthy athletes who performed voluntary sideways falls on a thick foam mattress. Several categories of falls were investigated (a) muscle-active vs muscle-relaxed falls; (b) falls from a standing position or from walking; and (c) falls in which an outstretched arm was used to break the fall. Each fall was videotaped at 60 frames s(-1). Fall kinematics parameters were obtained by digitizing markers placed on anatomical points of interest. The mean value for vertical hip impact velocity was 2.75 ms(-1) (+ or - 0.42 ms(-1) [S.D.]). The mean value for trunk angle (the angle between the trunk and the vertical) was 17.3 degrees (+ or - 11.5 degrees [S.D.]). We found a 38 percent reduction in the trunk angle at impact, and a 7 percent reduction in hip impact velocity for relaxed vs muscle-active falls. Finally, regarding the. falls in which an outstretched arm was used, only two out of the six subjects were able to break the fall with their arm or hand. For the remaining subjects hip impact occurred first, followed by contact of the arm or hand.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Postura
/
Accidentes por Caídas
/
Articulación de la Cadera
Tipo de estudio:
Etiology_studies
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Biomech
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos