The link between weight shift asymmetry and gait disturbances in chronic hemiparetic stroke patients

Figures & data

Table 1 Demographic and clinical characteristics

Characteristics	Poststroke group (n=22)	Control group (n=22)	Statistical tests; P-values
Age (years), mean (SD)	68 (11)	69 (7)	t=1.22; P=0.75
Gender (men), n (%)	14 (64)	14 (64)	χ^2=0.0; P=1.0
AIa, mean (SD)	0.09 (0.06)	0.03 (0.01)	t=3.07; P=0.00
GGI, mean (SD)	86.8 (45.2)	13.9 (6.3)	t=6.86; P=0.00
Walking speed (m/s), mean (SD)	0.41 (0.09)	1.39 (0.23)	t=4.67; P=0.00
Step length asymmetryb (m), mean (SD)	0.19 (0.02)	0.08 (0.01)	t=4.03; P=0.00
Time since stroke (months), mean (SD)	30 (1.92)
Brunnström recovery stage, maximum 6 (grade range)	4–6
Modified Modified Ashworth Scale, maximum 4 (grade range)	0–3
Medical Research Council Scale, minimum 0 (grade range)	3–5

Notes: Asymmetry of WB distributions, the GGI variables and selected spatiotemporal gait parameters (step length and walking speed) for the poststroke group (n=22) and control group (n=22), means (SD) of the outcome (95% CI), and comparison between the groups (statistical tests and P-values).

a AI = (NP − P)/(NP + P); NP = the nonparetic/dominant side percentage load distribution; and P = paretic/nondominant side percentage load distribution.

b NP − P; NP = the step length of nonparetic/dominant lower limb; and P = the step length of paretic/nondominant lower limb.

Abbreviations: AI, asymmetry index; GGI, Gillette Gait Index; WB, weight-bearing.

Table 2 The characteristics of gait parameters

Outcome	Poststroke group (n=22)	Control group (n=22)	Statistical tests; P-values
1. Time of toe-off (% gait cycle), mean (SD)	59.5 (6.78)	57.7 (9.38)	t=0.75; P=0.45
2. Walking speed/leg length (m/s), mean (SD)	0.56 (0.03)	1.27 (0.33)	t=−9.81; P=0.00
3. Cadence (step/second), mean (SD)	0.73 (0.41)	0.92 (0.12)	t=−4.54; P=0.00
4. Mean pelvic tilt (°), mean (SD)	13.67 (3.12)	6.28 (5.78)	t=5.27; P=0.00
5. ROM of pelvic tilt (°), mean (SD)	8.24 (3.21)	4.56 (1.42)	t=4.90; P=0.00
6. Mean pelvic rotation (°), mean (SD)	−8.61 (6.75)	0.41 (2.96)	t=−5.74; P=0.00
7. Minimum hip flexion (°), median (range)	−12.36 ([−37.02]–18.20)	−10.48 ([−18.39]–[−2.96])	U=210; P=0.45
8. ROM of hip flexion/extension (°), mean (SD)	14.37 (3.51)	32.36 (6.06)	t=−12.03; P=0.00
9. Peak hip abduction in swing (°), mean (SD)	11.54 (5.76)	1.76 (4.23)	t=6.41; P=0.00
10. Mean hip rotation in stance (°), median (range)	15.42 (10.44–27.40)	7.39 (−8.20–17.70)	U=48.00; P=0.00
11. Knee flexion at IC (°), mean (SD)	6.07 (3.01)	6.93 (3.36)	t=−0.89; P=0.37
12. Time of peak knee flex in swing (%), mean (SD)	44.94 (12.55)	62.96 (7.52)	t=−0.77; P=0.45
13. ROM of knee flexion (°), mean (SD)	30.23 (5.79)	58.70 (5.20)	t=−15.32; P=0.00
14. Peak dorsiflexion in stance (°), mean (SD)	−1.67 (1.94)	13.76 (3.52)	t=−18.01; P=0.00
15. Peak dorsiflexion in swing (°), mean (SD)	−2.75 (2.38)	6.77 (3.78)	t=−9.98; P=0.00
16. Mean foot progression (°), median (range)	−0.93 (−30.00–24.00)	13.26 (8.69–20.18)	U=32; P=0.00

Note: Means (SD) of the 16 gait parameters that composed the GGI for the paretic lower limb (poststroke group; n=22) and nondominant lower limb (control group; n=22), means (95% CI) of the between-group differences and statistical tests and P-values.

Abbreviations: GGI, Gillette Gait Index; IC, initial contact; ROM, range of motion; t, Student’s t-test for independent samples; U, Mann–Whitney U-test.

Table 3 The correlations between asymmetry index and Gillette Gait Index

Parameter	AI
	r	P-value
1. Time of toe-off (% gait cycle)	–	–
2. Walking speed/leg length (km/h)	−0.51	0.01
3. Cadence (step/second)	–	–
4. Mean pelvic tilt (°)	–	–
5. ROM of pelvic tilt (°)	–	–
6. Mean pelvic rotation (°)	–	–
7. Minimum hip flexion (°)	–	–
8. ROM of hip flexion/extension (°)	–	–
9. Peak hip abduction in swing (°)	–	–
10. Mean hip rotation in stance (°)	–	–
11. Knee flexion at IC (°)	–	–
12. Time of peak knee flex in swing (%)	–	–
13. ROM of knee flexion (°)	−0.48	0.04
14. Peak dorsiflexion in stance (°)	–	–
15. Peak dorsiflexion in swing (°)	−0.61	0.00
16. Mean foot progression (°)	–	–
GGI	0.47	0.03
Step length (m)	−0.68	0.00

Notes: Statistically significant correlations between AI and GGI, step length, and 16 distinct gait parameters that composed the GGI for the paretic lower limbs for the poststroke participants. r, Spearman’s rank correlation; P-value, statistical significance. AI of the posturographic weight-bearing distribution between body sides was calculated as follows: NP = the nonparetic/dominant side percentage load distribution, and P = paretic/nondominant side percentage load distribution.

Abbreviations: AI, asymmetry index; GGI, Gillette Gait Index; IC, initial contact; ROM, range of motion.