Smartphone-recorded real-world physical performance compared to standardized capacity-based outcome in patients with...

Area of Science:

• Biomedical Engineering
• Orthopedics
• Digital Health

Background:

• Degenerative lumbar disorders (DLD) with sciatica significantly impact patient mobility and function.
• Current assessment methods like patient-reported outcome measures (PROMs) and standardized tests may not fully capture real-world physical activity.
• Smartphones offer a continuous, accessible method for monitoring daily movement patterns, but their reliability in DLD sciatica patients is unestablished.

Purpose of the Study:

• To evaluate the accuracy of smartphone-derived daily step counts as a measure of real-life physical performance in patients with DLD-related sciatica.
• To examine the correlation between smartphone step counts and established subjective and objective outcome measures.

Main Methods:

• A prospective observational cohort study involving 50 patients with DLD-related sciatica scheduled for microsurgery.
• Physical performance assessed via smartphone step count and the 6-minute Walking Test (6WT-app).
• Subjective disability measured using paper-based PROMs (COMI-Back, ODI); data standardized using z-scores and analyzed with Spearman correlations.

Main Results:

• Mean daily step count was 4602 (z-score -1.1) and mean 6WT distance was 398 meters (z-score -1.4).
• Step count showed strong correlation with 6WT (r=0.70) and moderate correlations with ODI (r=-0.63) and COMI-Back (r=-0.65).
• Discrepancies noted between physical capacity and real-life performance, indicating distinct aspects of disability captured by each.

Conclusions:

• Smartphone-based step counting is a valid and objective indicator of physical performance in sciatica patients with DLD.
• The strong association with functional tests and self-reported disability suggests smartphone data can practically augment existing evaluation methods.