Concurrent validity and discriminative ability of force plate measures of balance during the sub-acute stage of stroke recovery

Raabeae Aryan; Kara K Patterson; Elizabeth L Inness; George Mochizuki; Avril Mansfield

doi:10.1016/j.gaitpost.2024.12.001

Concurrent validity and discriminative ability of force plate measures of balance during the sub-acute stage of stroke recovery

Gait Posture. 2024 Dec 5:117:31-37. doi: 10.1016/j.gaitpost.2024.12.001. Online ahead of print.

Authors

Raabeae Aryan¹, Kara K Patterson², Elizabeth L Inness², George Mochizuki³, Avril Mansfield⁴

Affiliations

¹ Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada; KITE Research Institute, Toronto Rehabilitation Institute-University Health Network, Toronto, ON, Canada.
² Rehabilitation Sciences Institute, University of Toronto, Toronto, ON, Canada; KITE Research Institute, Toronto Rehabilitation Institute-University Health Network, Toronto, ON, Canada; Department of Physical Therapy, University of Toronto, Toronto, ON, Canada.
³ School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, ON, Canada.
⁴ KITE Research Institute, Toronto Rehabilitation Institute-University Health Network, Toronto, ON, Canada; Evaluative Clinical Sciences, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Physical Therapy, University of Toronto, Toronto, ON, Canada. Electronic address: avril.mansfield@uhn.ca.

PMID: 39667307
DOI: 10.1016/j.gaitpost.2024.12.001

Abstract

Background: Many objective measures of balance control, including force plate measures of standing balance, lack sufficient validation for use in the stroke population.

Research questions: Do force plate measures of quiet standing balance during the sub-acute stage of stroke recovery have concurrent validity (i.e., correlate with functional balance measures) and discriminative ability (i.e., differentiate fallers from non-fallers and/or those with low-moderate versus high risk of falling)?

Methods: Participants completed one trial of quiet standing with eyes open, lasting for 30 seconds. History of falls was identified retrospectively, based on falls during the acute-care stay. Risk of falling was determined at admission to inpatient rehabilitation using the STRATIFY scale. Mean speeds of centre of pressure along the anterior-posterior and medial-lateral axes, weight-bearing asymmetry, and symmetry index were calculated. Concurrent validity of these measures were quantified against the Berg Balance Scale; their abilities in differentiating fallers from non-fallers, and individuals with low-moderate versus high risk of falling were evaluated using the area under the receiver operating curve (AUC).

Results: Among the measures studied, mean speeds of centre of pressure along the anterior-posterior and medial-lateral axes demonstrated moderate concurrent validity (ρ=-0.490, and -0.440, respectively; p-values≤0.002), while the other two measures did not show sufficient concurrent validity. Weight-bearing asymmetry showed some ability in differentiating fallers from non-fallers (AUC=0.67); however, other measures demonstrated negligible to no discriminative ability.

Significance: Our findings suggest that speeds of centre of pressure have moderate concurrent validity to quantify balance during the sub-acute stage of stroke; they can be used to better inform rehabilitation practice about the balance ability following a stroke. Weight-bearing asymmetry has some ability to discriminate people with and without a history of falls; however, research is required to identify its ability to discriminate future fallers and non-fallers.

Keywords: Biomechanics; Falls; Kinetics; Postural balance; Stroke; Validity.