Assessing Gait Function in Lower Limb Rehabilitation: The Role of the Gait Analysis and Motion Score (GAMS)

Abstract

Background: Assessment of gait function is crucial for optimising rehabilitation outcomes. The gait analysis and motion score (GAMS) summarises qualitative and quantitative gait parameters from treadmill-based analyses to evaluate functional walking status. Objectives: To assess the sensitivity of the GAMS for detecting short-term changes, its test-retest reliability, and its correlation with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Timed Up and Go (TUG) test. Methods: A retrospective analysis of 94 inpatient rehabilitation patients with hip, knee, or ankle impairments was performed. Changes in GAMS, WOMAC, and TUG scores and their interrelationships were assessed at both admission and discharge. Results: GAMS, WOMAC, and TUG showed significant improvements over time, with medium effect sizes (η² = 0.303 to 0.434; p < 0.001). No significant differences in outcome measures were observed between groups. Moderate to strong correlations were found between pre- and post-rehabilitation scores for GAMS, TUG, and WOMAC (r = 0.58 to r = 0.90), indicating good test-retest reliability. A significant low negative correlation between GAMS and TUG was observed for all patients at admission (r = -0.30, p = 0.003) and discharge (r = -0.26, p = 0.030). No significant correlations were observed between GAMS and WOMAC in any patient group. Baseline GAMS scores significantly influenced change scores. Conclusions: GAMS is a sensitive and reliable tool for detecting short-term changes in gait parameters. GAMS and TUG assess related but distinct constructs, with GAMS and WOMAC assessing different domains of gait function. Therefore, GAMS provides complementary information not captured by WOMAC or TUG.

Keywords: gait analysis; healthcare; lower extremity; outcome assessment; rehabilitation; reproducibility of results.

Figure 1

Comparison of performance using z-transformed T2D scores. TUG—Timed Up and Go test; WOMAC—Western Ontario and McMaster Universities Osteoarthritis Index; GAMS—gait analysis and motion score; z—z-transformed T2D scores, WOMAC and TUG T2D were inverted to align their scales with GAMS, ensuring that all measurements are presented in the same direction; 95% CI—error bars are at 95% confidence interval; p—significance level of ANOVA with group as independent variable; *—p-value of post hoc analysis, p < 0.05.

Figure 2

Dependence of changes on GAMS baseline value. GAMS—gait analysis and motion score; Δ [t1 − t2]—change score = discharge score—admission score; t1—time point of admission measurement; R² Linear—R-squared effect size of linear regression; Pearson correlation coefficient of admission and change score for GAMS, r = −0.45, p < 0.001; for TUG, r = −0.63, p < 0.001; for WOMAC, r = −0.65, p < 0.001.

Figure 3

Mean GAMS values for admission and discharge on item level. GAMS—gait analysis and motion score; mean scores for admission and discharge across the 15 items, two sub-domains and total; error bars at standard deviation; first ten items classified as visual parameters, last five items classified as technical parameters; scale from 0 (indicating impairment) to 1 (indicating no impairment); effect size η_p² (partial eta squared) for subdomains and total score; (*)—significance of ANOVA, p < 0.1; *—significance of ANOVA, p < 0.05; **—significance of ANOVA, p < 0.01; ***—significance of ANOVA, p < 0.001.