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Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb
Published on: August 30, 2016
Sensor-derived heel pressure metrics capture reversible gait dysfunction beyond conventional gait measures in normal
Seongmin Hong1, Wonhee Lee2, Seung-Ick Choi3
1Department of Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
Background:
The response to the cerebrospinal fluid (CSF) tap test helps determine the surgical eligibility of individuals with idiopathic normal pressure hydrocephalus (iNPH); however, conventional gait assessments have limited specificity and low negative predictive value. We investigated whether commercially available, low-cost sensor-embedded insoles could offer sensitive gait biomarkers for detecting changes in gait following the CSF tap test.
Methods:
Seventy-seven individuals with iNPH were prospectively enrolled. Participants performed conventional gait assessments, including the 10-m walking test (10MWT), wearing insoles with pressure sensors and an accelerometer before and after the CSF tap test. Spatiotemporal and plantar pressure parameters were compared between individuals with iNPH and control participants without iNPH and between responders and non-responders to the CSF tap test, defined by subjective and objective symptom improvements. Decision curve analysis evaluated clinical utility.
Results:
Individuals with iNPH exhibited significantly impaired gait and balance, reduced heel and toe pressures, and increased pressure variability compared with control participants. Responders (n = 48) demonstrated a significant post-tap increase in right heel pressure and decreased variability (p < 0.001 and p = 0.002, respectively), with sustained improvements at the 3-month follow-up in 19 participants who subsequently underwent surgical intervention. Decision curve analysis showed that models incorporating plantar pressure metrics in combination with the 10MWT yielded higher net benefit than the 10MWT model alone, with the greatest average Δnet benefit observed when multiple plantar pressure metrics were combined (+ 0.093).
Conclusion:
Sensor-derived heel pressure metrics represent a digitally quantifiable biomarker that enhances decision-analytic evaluation of CSF tap test response and may improve early treatment stratification in iNPH. Trial registration The project was retrospectively registered at ClinicalTrials.gov (NCT06722768) on December 9, 2024.
