Skip to main content

Medical Research Council-sumscore: a tool for evaluating muscle weakness in patients with post-intensive care syndrome

Dear Editor,

COVID-19 may lead to severe acute respiratory distress syndrome requiring intensive care unit (ICU) support. Patients surviving respiratory distress could develop post-intensive care syndrome (PICS) that includes ICU-acquired weakness (ICUAW). Nearly 66% of COVID-19 patients have clinically important muscle weakness following discharge [1]. Therefore, communication between the critical care and rehabilitation physician is important to evaluate the physical function of COVID-19 survivors to start rehabilitation timely.

The comprehensive examination of muscle strength in COVID-19 is not easy. Muscle strength can be evaluated by manual muscle testing and dynamometer. Electrophysiological study is important in diagnosing critical illness neuromyopathy; however, its correlation with muscle weakness is not clear. Ultrasonography can detect atrophy and structural changes but does not correlate with muscle function [2].

Medical Research Council (MRC)-sumscore evaluates global muscle strength. Manual strength of six muscle groups (shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion) is evaluated on both sides using MRC scale. Summation of scores gives MRC-sumscore, ranging from 0 to 60. This score was developed for detecting early strength alterations in patients with Guillain-Barré syndrome, especially who were bedridden and receiving artificial ventilation. The sensitivity and interobserver agreement of MRC-sumscore was demonstrated [3]. Despite its ceiling effect, this score reliably identifies significant weakness (< 48) and even better in severe weakness (< 36) [4] which is the main medical interest for treatment in ICUAW.

Handgrip strength is a rapid, simple, and objective tool that is measured by handheld dynamometer represents global muscle strength. The cutoff value for handgrip strength in critically ill patients is defined as < 11 kg force for males and < 7 kg force for females which is below that of the age- and sex-matched patients [5]. It was proposed as an alternative to MRC in ICUAW [5]. However, examination of other muscles by MRC-sumscore might give additional information since the neurological consequences of COVID-19 are not clear yet. ICUAW is more pronounced in proximal muscles; therefore, direct evaluation of proximal muscles is also valuable. MRC is associated with mortality, hospital, and ICU-free days in ICUAW more strongly than handgrip strength [5].

In conclusion, MRC-sumscore is a valid, reliable, objective, and easy method to evaluate the global muscle strength including PICS related to COVID-19. It provides beneficial information about the clinical course. Its bedside applicability without necessitating any device makes MRC-sumscore a valuable tool in the follow-up of patients with PICS.

Availability of data and materials

Not applicable



Intensive care unit


Intensive care unit acquired weakness


Medical Research Council


Post-intensive care syndrome


  1. Wang Z, Wang Z, Sun R, Wang X, Gu S, Zhang X, et al. Timely rehabilitation for critical patients with COVID-19: another issue should not be ignored. Version 2. Crit Care. 2020;24(1):273.

    Article  PubMed Central  PubMed  Google Scholar 

  2. Hermans G, Van den Berghe G. Clinical review: intensive care unit acquired weakness. Crit Care. 2015;19(1):274.

    Article  PubMed Central  PubMed  Google Scholar 

  3. Kleyweg RP, van der Meché FG, Schmitz PI. Interobserver agreement in the assessment of muscle strength and functional abilities in Guillain-Barré syndrome. Muscle Nerve. 1991;14(11):1103–9.

    Article  CAS  PubMed  Google Scholar 

  4. Hermans G, Clerckx B, Vanhullebusch T, Segers J, Vanpee G, Robbeets C, et al. Interobserver agreement of Medical Research Council sum-score and handgrip strength in the intensive care unit. Muscle Nerve. 2012;45(1):18–25.

    Article  PubMed  Google Scholar 

  5. Ali NA, O’Brien JM Jr, Hoffmann SP, Phillips G, Garland A, Finley JC, et al. Acquired weakness, handgrip strength, and mortality in critically ill patients. Am J Respir Crit Care Med. 2008;178(3):261–8.

    Article  PubMed  Google Scholar 

Download references


Not applicable


No competing interest exist.

Author information

Authors and Affiliations



ZT contributed substantially to the conception and design of the study, drafted and provided critical revision of the article, and took responsibility in necessary literature review for the study. MT contributed substantially to the conception of the study and took responsibility in necessary literature review for the study. OOT contributed substantially to the conception and design of the study and drafted and provided critical revision of the article. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Zeynep Turan.

Ethics declarations

Ethics approval and consent to participate

Not applicable

Consent for publication

Not applicable

Competing interests

No competing interest exist.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Turan, Z., Topaloglu, M. & Ozyemisci Taskiran, O. Medical Research Council-sumscore: a tool for evaluating muscle weakness in patients with post-intensive care syndrome. Crit Care 24, 562 (2020).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: