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Updated: May 6, 2026

Manual Muscle Testing: A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients
Published on: April 12, 2011
[Evolution in muscle strength in critical patients with invasive mechanical ventilation]
G Via Clavero1, M Sanjuán Naváis, M Menéndez Albuixech
1Unidad de Cuidados Intensivos, Hospital Universitari de Bellvitge-IDIBELL, L'Hospitalet de Llobregat, Barcelona, España; Departamento Enfermería Fundamental y Médico-Quirúrgica, Escuela Universitaria de Enfermería, Universidad de Barcelona, L'Hospitalet de Llobregat, Barcelona, España.
Objective:
To assess the evolution of muscle strength in critically ill patients with mechanical ventilation (MV) from withdrawal of sedatives to hospital discharge.
Material And Method:
A cohort study was conducted in two intensive care units in the Hospital Universitari de Bellvitge from November 2011 to March 2012.
Inclusion Criteria:
Consecutive patients with MV > 72h. Dependent outcome: Muscle strength measured with the Medical Research Council (MRC) scale beginning on the first day the patient was able to answer 3 out of 5 simple orders (day 1), every week, at ICU discharge and at hospital discharge or at day 60 Independent outcomes: factors associated with muscle strength loss, ventilator-free days, ICU length of stay and hospital length of stay. The patients were distributed into two groups (MRC< 48, MRC ≥ 48) after the first measurement.
Results:
Thirty-four patients were assessed. Independent outcomes associated with muscle strength weakness were: days with cardiovascular SOFA >2 (P<.001) and days with costicosteroids (P<.001). Initial MRC in MRC<48 group was 38 (27-43), and 52 (50-54) in MRC ≥ 48. The largest muscle strength gain was obtained the first week (31% versus 52%). A MRC < 48 value was associated with more MV days (P<.007) and a longer ICU stay. (P<.003).
Conclusion:
The greatest muscle strength gain after withdrawing of the sedatives was achieved in the first week. Muscle strength loss was associated with a cardiovascular SOFA > 2 and costicosteroids. Patients with a MRC < 48 required more days with MV and a longer ICU stay.
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