Movement variability in stroke patients and controls performing two upper limb functional tasks: a new assessment...

Area of Science:

• Biomedical Engineering
• Rehabilitation Science
• Movement Science

Background:

• Current clinical assessments for upper limb impairment post-stroke lack detailed kinematic analysis.
• Existing methods struggle to quantify movement variability during functional tasks.
• A gap exists between complex motion capture systems and simple clinical tests.

Purpose of the Study:

• To present a novel, user-friendly methodology for assessing upper limb movement variability.
• To evaluate signal magnitude and timing variability in upper limb movement trajectories.
• To compare movement variability between stroke patients and matched controls during functional tasks.

Main Methods:

• Utilized dynamic time warping for curve registration to analyze accelerometer data.
• Quantified variability in signal timing and signal magnitude.
• Compared six stroke patients and six matched controls performing unilateral (drinking) and bilateral (plate moving) tasks.

Main Results:

• Significant differences in timing variability were found for the 'drinking' task in stroke patients compared to controls (p = 0.002, p = 0.008).
• Stroke patients exhibited increased signal timing variability during unilateral task performance.
• The 'moving a plate' task showed less distinct group differences.

Conclusions:

• Movement variability metrics, assessed via the new methodology, differ between stroke patients and controls during unilateral tasks.
• The use of inexpensive accelerometers makes this method suitable for routine clinical evaluation.
• Further research with larger studies is recommended to validate the metrics for quantifying impairment levels.