Contribution of Muscle Strength and Integration of Afferent Input to Postural Instability in Persons with Stroke

Objective. To determine the relationship of muscle strength to postural sway in persons with stroke under standing conditions in which vision and ankle proprioception were manipulated. Methods. Forty persons with stroke and 40 healthy older adult controls were recruited from the community and underwent balance testing consisting of 6 conditions that manipulate vision and somatosensory information while standing. Postural sway was measured during each condition. In addition, lower extremity joint torques and cutaneous sensation from the plantar surface of the foot were assessed. Results. Postural sway was increased with more challenging standing conditions (i.e., when multiple sensory systems were manipulated) to a greater extent with the group with stroke compared to controls. Muscle strength was only correlated to sway during the most challenging conditions. Furthermore, a greater number of persons with stroke fell during the balance testing compared to controls. Conclusions. Impairments in re-weighting/integrating afferent information, in addition to muscle weakness, appear to contribute to postural instability and falls in persons with stroke. These findings can be used by clinicians to design effective interventions for improving postural control following stroke.

[1]  J. Eng,et al.  Reliability and comparison of weight-bearing ability during standing tasks for individuals with chronic stroke. , 2002, Archives of physical medicine and rehabilitation.

[2]  M. Redfern,et al.  Attention influences sensory integration for postural control in older adults. , 2001, Gait & posture.

[3]  Aftab E Patla,et al.  Contribution of vision and cutaneous sensation to the control of centre of mass (COM) during gait termination , 2001, Brain Research.

[4]  J. Eng,et al.  Reliability of lower extremity strength measures in persons with chronic stroke. , 2002, Archives of physical medicine and rehabilitation.

[5]  P. E. Sullivan,et al.  Balance and physical impairments after stroke. , 1999, Archives of physical medicine and rehabilitation.

[6]  A. Forster,et al.  Incidence and consequences offalls due to stroke: a systematic inquiry , 1995, BMJ.

[7]  L. Wolfson,et al.  Altered sensory function and balance in older persons. , 1993, Journal of gerontology.

[8]  R. A. Davidoff.  The pyramidal tract. , 1990, Neurology.

[9]  Ann Ashburn,et al.  Fall events among people with stroke living in the community: circumstances of falls and characteristics of fallers. , 2002, Archives of physical medicine and rehabilitation.

[10]  T. Mergner,et al.  Human balance control during cutaneous stimulation of the plantar soles , 2001, Neuroscience Letters.

[11]  T. Brandt,et al.  Sensory system interactions during simultaneous vestibular and visual stimulation in PET , 2002, Human brain mapping.

[12]  S. Gandevia,et al.  The distribution of muscle weakness in upper motoneuron lesions affecting the lower limb. , 1990, Brain : a journal of neurology.

[13]  J. Kaye,et al.  Balance in the healthy elderly: posturography and clinical assessment. , 1997, Archives of neurology.

[14]  J. Furman,et al.  Role of Posturography in the Management of Vestibular Patients , 1995, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[15]  S. Ron,et al.  The vestibulo-ocular reflex and dysequilibrium after hemispheric stroke. , 1994, American journal of physical medicine & rehabilitation.

[16]  E. Roth,et al.  The American Heart Association Stroke Outcome Classification: executive summary. , 1998, Circulation.

[17]  M. Woollacott,et al.  Multisensory training of standing balance in older adults: I. Postural stability and one-leg stance balance. , 1994, Journal of gerontology.

[18]  J. Roll,et al.  The plantar sole is a ‘dynamometric map’ for human balance control , 1998, Neuroreport.

[19]  H. Menz,et al.  Visual contribution to postural stability in older adults , 2000 .

[20]  F O Black,et al.  What Can Posturography Tell Us About Vestibular Function? , 2001, Annals of the New York Academy of Sciences.

[21]  J. Mizrahi,et al.  Postural stability in stroke patients: Vectorial expression of asymmetry, sway activity and relative sequence of reactive forces , 1989, Medical and Biological Engineering and Computing.

[22]  T. Brandt,et al.  The Vestibular Cortex: Its Locations, Functions, and Disorders , 1999, Annals of the New York Academy of Sciences.

[23]  L. Brown,et al.  Attentional demands for static postural control after stroke. , 2002, Archives of physical medicine and rehabilitation.

[24]  E. Vicaut,et al.  Reliance on visual information after stroke. Part I: Balance on dynamic posturography. , 2004, Archives of physical medicine and rehabilitation.

[25]  Marjorie H. Woollacott,et al.  Motor Control: Theory and Practical Applications , 1995 .

[26]  J. Wyman,et al.  Test-retest reliability of the sensory organization test in noninstitutionalized older adults. , 1995, Archives of physical medicine and rehabilitation.