Evaluating the Intensity of Muscle Contraction by Near‐Infrared Spectroscopy, a Potential Application for Scaling Muscle Spasm

• DOI: 10.1002/jbio.70020
• Publication Date: 2025-04-05T00:48:24Z
• Authors: Mehdi Nourizadeh; Yekta Saremi; Amir Parham Pirha...; Sepideh Mortezane...; Iman Amani Tehrani; Jocelyn Bégin; Maria Juricic; Kishore Mulpuri; Babak Shadgan
• Keywords: Intensity

Muscle spasticity, common in conditions such as cerebral palsy, spinal cord injury, and multiple sclerosis, is traditionally assessed using the Modified Ashworth Scale, which lacks consistency. This study evaluates near-infrared spectroscopy (NIRS) a non-invasive tool for measuring muscle contraction intensity. Thirty-seven healthy adults performed isometric contractions at varying intensities (15%, 30%, 45%, 60% of maximal voluntary contraction), with NIRS sensors monitoring changes Tissue Oxygenation Index (TOI) electromyography (EMG) activity. Results demonstrated significant negative correlation between intensity ΔTOI, indicating that higher levels resulted greater reductions oxygenation. Additionally, multinomial logistic regression model confirmed TOI could reliably predict (p < 0.001). technique provide real-time, objective data spasticity assessment, potentially improving treatment plans.