Age and height effects on the center of mass and center of pressure inclination angles during obstacle-crossing.

Tripping over obstacles has been reported as one of the most frequent causes of falls in the elderly. Maintenance of the body's balance and precise swing foot control is essential for successful obstacle-crossing. The aim of this study was thus to investigate the height and age effects on the center of mass (COM) and center of pressure (COP) inclination angles and angular velocities during obstacle-crossing. Ten healthy young and 15 healthy older adults were recruited to walk and cross obstacles of heights of 10%, 20% and 30% of their leg lengths. The COM and COP position data were calculated using data measured from a three-dimensional (3D) motion analysis system and forceplates. Smaller medial COM-COP inclination angles were found in the older group, suggesting that the neuromusculoskeletal system may have more room to control the swing foot with sufficient foot clearance. Decreased inclination angles with increasing obstacle height suggest that the subjects tended to keep their COM position close to the COP position to increase the body's stability. Greater anterior inclination angular velocities were found in the older group to maintain the same inclination angles as the young. Not only inclination angles, but also COM-COP angular velocity, were useful for assessing one's ability to control the body's dynamic stability.

[1]  D. Winter,et al.  Control of whole body balance in the frontal plane during human walking. , 1993, Journal of biomechanics.

[2]  M. Borrie,et al.  Circumstances and consequences of falls experienced by a community population 70 years and over during a prospective study. , 1990, Age and ageing.

[3]  C Kirtley,et al.  Influence of walking speed on gait parameters. , 1985, Journal of biomedical engineering.

[4]  J. Collins,et al.  Open-loop and closed-loop control of posture: A random-walk analysis of center-of-pressure trajectories , 2004, Experimental Brain Research.

[5]  Y. Pai,et al.  Control of body centre of mass momentum during sit-to-stand among young and elderly adults , 1994 .

[6]  L. Draganich,et al.  Stepping over an obstacle increases the motions and moments of the joints of the trailing limb in young adults. , 1997, Journal of biomechanics.

[7]  K R Kaufman,et al.  Motion of the whole body's center of mass when stepping over obstacles of different heights. , 2001, Gait & posture.

[8]  S. Ebrahim,et al.  Falls by elderly people at home: prevalence and associated factors. , 1988, Age and ageing.

[9]  M. Orendurff,et al.  The effect of walking speed on center of mass displacement. , 2004, Journal of rehabilitation research and development.

[10]  R. Craik,et al.  Gait Variability in Community‐Dwelling Older Adults , 2001, Journal of the American Geriatrics Society.

[11]  Begg,et al.  Time-domain analysis of foot-ground reaction forces in negotiating obstacles. , 1998, Gait & posture.

[12]  Hao-Ling Chen,et al.  Effects of obstacle height on the control of the body center of mass motion during obstructed gait , 2007 .

[13]  Aftab E. Patla,et al.  The role of active forces and intersegmental dynamics in the control of limb trajectory over obstacles during locomotion in humans , 2004, Experimental Brain Research.

[14]  M. Hahn,et al.  Age-related reduction in sagittal plane center of mass motion during obstacle crossing. , 2004, Journal of biomechanics.

[15]  K D Kochanek,et al.  Deaths: final data for 1999. , 2001, National vital statistics reports : from the Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System.

[16]  T. S. Wei,et al.  Fall Characterictics, Functional Mobility and Bone Mineral Density as Risk Factors of Hip Fracture in the Community-Dwelling Ambulatory Elderly , 2001, Osteoporosis International.

[17]  T. Lu,et al.  Comparisons of the lower limb kinematics between young and older adults when crossing obstacles of different heights. , 2006, Gait & posture.

[18]  L. Chou,et al.  Detection of gait instability using the center of mass and center of pressure inclination angles. , 2006, Archives of physical medicine and rehabilitation.

[19]  V. Dietz,et al.  Influence of subjects' height on the stabilization of posture. , 1992, Acta oto-laryngologica.

[20]  A L Hof,et al.  The condition for dynamic stability. , 2005, Journal of biomechanics.

[21]  P. Goldie,et al.  Force platform measures for evaluating postural control: reliability and validity. , 1989, Archives of physical medicine and rehabilitation.

[22]  Tung-Wu Lu,et al.  Comparisons of the joint moments between leading and trailing limb in young adults when stepping over obstacles. , 2006, Gait & posture.

[23]  J. Saunders,et al.  The major determinants in normal and pathological gait. , 1953, The Journal of bone and joint surgery. American volume.

[24]  K. Kaufman,et al.  Medio-lateral motion of the center of mass during obstacle crossing distinguishes elderly individuals with imbalance. , 2003, Gait & posture.

[25]  M. Tinetti,et al.  Prevention of falls among the elderly. , 1989, The New England journal of medicine.

[26]  Herman J. Woltring,et al.  A fortran package for generalized, cross-validatory spline smoothing and differentiation , 1986 .

[27]  Y. Pai,et al.  Center of mass velocity-position predictions for balance control. , 1997, Journal of biomechanics.

[28]  A. N. Exton-smith,et al.  Falls in the elderly related to postural imbalance. , 1977, British medical journal.

[29]  D Fife,et al.  Northeastern Ohio Trauma Study III: incidence of fractures. , 1985, Annals of emergency medicine.

[30]  Wynne A. Lee,et al.  Evaluation of a model that determines the stability limits of dynamic balance. , 1999, Gait & posture.