Minimal detectable change for gait variables collected during treadmill walking in individuals post-stroke

Area of Science:

• Rehabilitation Medicine
• Biomechanical Engineering
• Neuroscience

Background:

• Post-stroke gait impairments significantly affect mobility and community participation.
• Treadmill training is an effective rehabilitation strategy for improving gait post-stroke.
• Assessing gait performance often involves kinematic and kinetic data from treadmill walking.

Purpose of the Study:

• To compute minimal detectable change (MDC) values for post-stroke gait kinematics, ground reaction force (GRF) indices, and spatial-temporal measures during treadmill walking.
• To provide a reference for interpreting the significance of gait changes following interventions.
• To address the lack of reported MDC values for these specific gait variables in the post-stroke population.

Main Methods:

• Nineteen individuals with chronic post-stroke hemiparesis underwent two gait testing sessions on a treadmill.
• Gait variables including kinematics (joint angles), GRF, temporal, and spatial measures were collected.
• Test-retest reliability was assessed using intraclass correlation coefficients (ICCs) to calculate MDCs.

Main Results:

• Excellent test-retest reliability was observed for all tested gait variables (ICCs ranging from 0.799 to 0.986).
• Specific MDCs were reported for hip, knee, and ankle joint angles, peak anterior and mean vertical GRF, temporal variables, and paretic step length.
• Ranges for MDCs included joint angles (3.8°–11.5°), GRF (2.85%–4.65% body weight), temporal variables (3.2%–4.2% gait cycle), and paretic step length (6.7 cm).

Conclusions:

• The computed MDCs offer a crucial reference for clinicians and researchers.
• These values enable the differentiation of true gait improvements from measurement error or day-to-day variability.
• The findings support the use of these MDCs in evaluating the effectiveness of gait rehabilitation interventions post-stroke.