Robotic arm assisting in stroke rehabilitation

Beyond the Ashworth Scale: Can Robotics Revolutionize Spasticity Assessment?

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Rhea Morgan in Health & Wellness December 2025 • 4 min read.

"A new study explores how the REAplan robotic device offers a more objective and sensitive way to measure upper limb spasticity in stroke patients, potentially transforming rehabilitation strategies."


Spasticity, a common consequence of stroke and other central nervous system lesions, significantly impairs motor function and diminishes the quality of life for affected individuals. Traditional methods of assessing spasticity, such as the Modified Ashworth Scale (MAS), rely on subjective clinical evaluations, which can suffer from variability and limited sensitivity.

The quest for more objective and reliable spasticity assessment tools has led researchers to explore innovative technologies, including robotics. A recent study published in the Journal of Rehabilitation Medicine investigates the potential of the REAplan, a robotic device, to quantify upper limb spasticity in stroke patients by measuring resistance force during passive movements.

This article delves into the methodology, findings, and implications of this study, offering insights into how robotic assessments like REAplan could revolutionize spasticity management and rehabilitation strategies for individuals recovering from stroke.

REAplan: A Robotic Approach to Measuring Spasticity

Robotic arm assisting in stroke rehabilitation

The study, led by researchers at the Université catholique de Louvain, involved twelve patients with chronic stroke and upper limb spasticity. The core objective was to determine if the REAplan robotic device could accurately measure overall upper limb peak resistance force, serving as an indicator of spasticity. Here's how the study was conducted:

To validate the REAplan's measurements, researchers compared its results to the MAS, the current standard for clinical spasticity assessment. Furthermore, they analyzed the robot's sensitivity by assessing changes in resistance force after administering a musculocutaneous motor nerve block (MNB) to reduce elbow flexor spasticity.

  • Robotic Mobilization: The REAplan robot passively moved each patient's upper limb through a back-and-forth trajectory at various velocities (10, 20, 30, 40, and 50 cm/s).
  • Resistance Force Measurement: The robot's sensors recorded the resistance force encountered during each forward movement (elbow extension). Ten movements were performed at each velocity, and the average peak resistance force was calculated.
  • Motor Nerve Block: Patients received a musculocutaneous motor nerve block to temporarily reduce spasticity in the elbow flexor muscles. Assessments with the REAplan and MAS were conducted before and after the nerve block to evaluate the robot's sensitivity to changes in muscle tone.
The results showed a strong correlation between the REAplan measurements and the MAS scores, especially at mobilization velocities of 30 cm/s or higher. This suggests that the robotic device can provide a reliable and objective assessment of spasticity that aligns with clinical evaluations. The study also found that the REAplan was sensitive to changes in spasticity, as evidenced by the reduction in resistance force after the motor nerve block at higher velocities (40 and 50 cm/s).

The Future of Spasticity Assessment

This study highlights the potential of robotics to enhance the objectivity and sensitivity of spasticity assessments. The REAplan device offers a promising alternative to traditional manual scales, providing clinicians with more precise data to guide treatment decisions and monitor patient progress.

While the study's sample size was relatively small, the findings warrant further investigation with larger cohorts and diverse patient populations. Future research could explore the integration of robotic assessments into routine rehabilitation programs to personalize treatment strategies and optimize outcomes.

By incorporating robotic assessments such as REAplan into rehabilitation protocols, healthcare professionals can potentially deliver more effective and tailored interventions, ultimately improving the lives of individuals affected by spasticity.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.2340/16501977-2248, Alternate LINK

Title: Assessment Of Upper Limb Spasticity In Stroke Patients Using The Robotic Device Reaplan

Subject: Rehabilitation

Journal: Journal of Rehabilitation Medicine

Publisher: Medical Journals Sweden AB

Authors: S Dehem, M Gilliaux, T Lejeune, C Detrembleur, D Galinski, J Sapin, M Vanderwegen, G Stoquart

Published: 2017-01-01

Everything You Need To Know

1

What is spasticity, and why is it a concern?

Spasticity is a condition characterized by increased muscle tone, leading to stiffness and resistance to movement. It often results from damage to the central nervous system, such as after a stroke or other neurological injuries. This impairs motor function and reduces the quality of life for individuals affected by it.

2

What is the Modified Ashworth Scale (MAS), and what are its limitations?

The Modified Ashworth Scale (MAS) is a common clinical tool used to assess spasticity. It involves a subjective manual evaluation by clinicians to gauge the resistance to passive movement in a limb. However, the MAS relies on the clinician's judgment, which can introduce variability and limit the sensitivity of the assessment. This can lead to inconsistent diagnoses and treatment plans.

3

How does the REAplan robotic device work to assess spasticity?

The REAplan robotic device is an innovative tool used to measure spasticity. It measures the resistance force during passive movements of the upper limb. The study used the REAplan to move the patient's arm through a range of motion at different speeds and measure the force encountered. This provides an objective measure of spasticity, unlike the subjective evaluation of the Modified Ashworth Scale (MAS).

4

What is the significance of the study using the REAplan device?

The study's significance lies in the potential of the REAplan device to provide a more objective and sensitive assessment of spasticity compared to traditional methods such as the Modified Ashworth Scale (MAS). The REAplan demonstrated a strong correlation with MAS scores and was also sensitive to changes in spasticity after a motor nerve block. This advancement could revolutionize how clinicians evaluate spasticity, leading to more accurate diagnoses and improved treatment outcomes for stroke patients and others affected by this condition.

5

What are the broader implications of using the REAplan for spasticity assessment?

The implications of using the REAplan robotic device are far-reaching. By providing objective measurements of spasticity, clinicians can make more informed decisions about treatment strategies, monitor patient progress more accurately, and tailor interventions to individual needs. This could lead to improved rehabilitation outcomes, enhanced motor function, and a better quality of life for individuals recovering from stroke. Furthermore, the use of robotic technology like the REAplan represents a significant step forward in the field of rehabilitation medicine, paving the way for more advanced and personalized approaches to spasticity management.

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