Table 1.

Study characteristics.

Author (year)	Study design	Number of participants with stroke	Participant characteristics (1) Age (years) (2) Time after stroke	Baseline measures of stroke severity	Baseline measures of clinical balance /ambulatory performance	Category of balance measure	Dependent measures of postural stability	Statistics for association between WBA and postural stability
Van Asseldonk et al. (2006) [29]	Cross-sectional	N = 8	(1) 59.9 (8.3) (2) 42.4 (17.1) months	MI 51.5 (16.1)	FAC (4-5) BBS 49 (7.6) TUG 21.8 (11.9) TBT (3–4)	DP	Contribution of paretic leg to balance controla	↑ R 2 = 0.26
Mansfield et al. (2011) [10]	Cross-sectional	N = 33	(1) 61 (14) (2) 133 (194) days	NIHSS 4.6 (4.1) ChMcS-leg 4.6 (1.3) ChMcS-foot 4.2 (1.6)	BBS 37.9 (15.6)	QS	COP amplitude synchronizationb	↑ R 2  = 0.19–0.23
Mansfield et al. (2012) [30]	Cross-sectional Retrospective chart Review	N = 100	(1) 66.9 (14.9) (2) 22.9 (23.5) days	NIHSS 3.5 (3.0) ChMcS-leg 4.8 (1.3) ChMcS-foot 4.5 (1.4)	BBS 36.9 (14.6)	QS      CB    FA	COP amplitude synchronizationb   BBS    Faller status	↑ R 2 = 0.032–0.053      ↑ R 2  = 0.049–0.057   Multiple linear regression   P = 0.060 Multiple logistic regression
Marigold et al. (2004) [26]	Cross-sectional	N = 10	(1) 61.3 (8.9) (2) 4.1 (2.9) years	Not reported	BBS 44.9 (8.3)	DP	TA amplitude MG amplitude    TA onset latencies MG onset latencies	F2,18 = 1.51(p), 0.67(np)   ↑ F 2,18  = 6,14(p), 3,78(np)   Anova   F2,18 = 0.15(p), 0.78(np)   F2,18 = 0.19(p), 0.70(np)
Marigold and Eng (2006) [25]	Cross sectional	N = 28	(1) 62.1 (8.6) (2) 4.1 (2.7) years	ChMcS-leg 4 (3-5) ChMcS-foot 5 (4–6)	BBS 46.2 (42.4–48.6) IQR	QS	COP amplitude (AP) COP velocity (AP) COP amplitude (ML) COP velocity (ML)	↑ R 2 = 0.0049 ↑ R 2 = 0.01 ↑ R 2 = 0.044 ↑ R 2  = 0.22
Pereira et al. (2010) [27]	Cross-sectional	N = 14	(1) 65 (10) (2) 29 (23) months	Not reported	Not reported	CB	Functional Reach	NS total group ↓R 2 = 0.10
Peurala et al. (2007) [28]	Cross-sectional	N = 45	(1) Left hemi 53.4 (8) Right hemi 55.1 (8) (2) Left hemi 3.1 (4.8) years Right hemi 2.8 (2.8) years	FIM Left hemi 103.4 (10) Right hemi 101.1 (13)	FAC (2–5)	QS	COP velocity (AP) COP velocity (ML) Power peak magnitude (AP)c Power peak magnitude (ML)c	↑ R 2  = 0.18, ↑ R 2  = 0.25   ↑ R 2  = 0.09–0.14      ↑ R 2  = 0.12–0.20
Roerdink et al. (2009) [24]	Cross-sectional*	N = 33	(1) 61.2 (13.0) (2) 9.8 (5.4) weeks	BFM II–VI	FAC 1–4	QS	Sway aread	↑ R 2 = 0.073
Sackley (1991) [8]	Longitudinal cohort	N = 92	(1) 63.3 (21–87) (2) 11.3 (5) weeks	Not reported	Not reported	FA	Number of falls	NS

Values for descriptive data represent mean (sd) unless stated otherwise. Statistics represent R ² as calculated from bivariate correlations unless stated otherwise. Significant associations are presented in bold. ↑: greater WBA is associated with more postural instability, ↓: greater WBA is associated with less postural instability AP: anteroposterior, BBS: Berg Balance Scale, BFM: Brunnstrom Fugl-Meyer assessment, CB: clinical balance test, ChMcS: Chedoke-McMaster Stroke assessment scores, COP: center of pressure, DP: dynamic posturography, FA: falls in daily life, FAC: Functional Ambulation Categories, FIM: Functional Independence Measure, FR: Functional Reach test, IQR: interquartile range, MG: medial gastrocnemius, MI: Motricity Index, ML: mediolateral, N: number of stroke participants, NIHSS: National Institutes of Health Stroke Scale, NP: non-paretic, NS: no significant association with WBA, p: paretic, QS: quiet standing posturography, TA: tibialis anterior, TBT: Timed Balance Test, TUG: Timed Up and Go test, WBA: weight-bearing asymmetry. *Longitudinal study, but correlations between WBA and postural control were analyzed cross-sectionally. ^a% contribution of the paretic leg to total amount of generated corrective torque. ^bCalculated by cross-correlating COP amplitude time series, ^cpower spectral density functions, ^dtotal area covered by the COP trajectory.