Related Experiment Video
Updated: Feb 27, 2026
Quantified Assessment of Infant's Gross Motor Abilities Using a Multisensor Wearable
Published on: May 17, 2024
GriFT: A Device for Quantifying Physiological and Pathological Mirror Movements in Children
Insights
This study introduces the grip force tracking (GriFT) device for quantitatively assessing mirror movements (MM) in children. The GriFT device shows high sensitivity in categorizing physiological MM and clinical applicability for children with unilateral cerebral palsy.
Area of Science:
- Neuroscience
- Motor Control
- Pediatric Neurology
Background:
- Mirror movements (MM) are involuntary actions in the passive limb mirroring voluntary movements.
- MM are typical in children but diminish with age.
- Current MM assessment relies on subjective ordinal scales, limiting clinical utility.
Purpose of the Study:
- To introduce and validate the grip force tracking (GriFT) device for quantitative MM assessment.
- To assess the feasibility and clinical applicability of GriFT in children.
- To explore GriFT's potential for diagnosing and managing neurological disorders like unilateral cerebral palsy.
Main Methods:
- Developed a portable grip force tracking (GriFT) system with force sensors.
- Children performed repetitive unimanual squeezing tasks synchronized with a computer game.
- MM were analyzed based on frequency, amplitude, and temporal synchronization features.
Main Results:
- The GriFT device demonstrated feasibility and validity in typically developing children (N=174, ages 5-15).
- MM frequency and amplitude were key discriminators between clinical MM scores.
- Physiological MM categorization achieved high sensitivity (89%-97%).
Conclusions:
- The GriFT device offers a quantitative and sensitive method for MM assessment.
- The system shows clinical applicability for children with unilateral cerebral palsy.
- Quantitative MM analysis is a promising tool for research and clinical practice in pediatric neurology.
Goal:
Mirror movements (MM) occur during unilateral actions and manifest as involuntary muscle activity of the passive limb, "mirroring" voluntary actions executed by the contralateral homologous body part. They are a normal motor feature in young children that gradually disappears. In children suffering from neurological disorders, e.g., unilateral cerebral palsy, MMs have been proposed to yield relevant information for diagnosis and therapy. However, in clinical practice, MM are typically assessed using an ordinal rating scale. Here, we introduce the grip force tracking (GriFT) device, a portable system to quantitatively assess MM during repetitive unimanual squeezing while playing a computer game.
Methods:
The GriFT device consists of two handles, each equipped with two compressive force sensors (range 0-23 kg, Fz 1000 Hz). Children complete three trials of unimanual squeezing, whereby the visual display on the screen determines the squeezing rhythm (0.67 Hz at 15% maximum voluntary contraction, force-level adjusted per hand). MMs are characterized based on frequency, amplitude, and temporal features (synchronization, timing).
Results:
MM differed significantly between children with different clinical MM scores. MM frequency and amplitude were most discriminative. Categorization of physiological MM proved highly sensitive (89%-97%).
Conclusion:
We demonstrated feasibility and validity of the GriFT device in a large cohort of typically developing children (N = 174, age 5-15 years), and its clinical applicability in children with unilateral cerebral palsy with various levels of hand function.
Significance:
The quantification of MM is a promising tool to further investigate and categorize MM in children with unilateral cerebral palsy.
