Muscle weakness associated with hospitalization is known to be a significant predictor of functional decline in older adults hospitalized for acute conditions. Previous studies have shown that physical and functional decline associated with hospitalization in older adults considerably lengthened hospital stays and increased post-discharge caregiver burden, risk of disability and death and medical expenses. The most widely used muscle strength assessments in hospital settings are handgrip dynamometry and the Medical Research Council (MRC) scale. However, the MRC score is time-consuming to obtain in hospitalized patients and requires adequate training. As such, in hospital settings handgrip dynamometry is noteworthy for its consistent measurements, short application time, simplicity and objectivity in application and scoring and ability to identify overall muscle strength.

Investigate the association and agreement between handgrip dynamometry measures and the MRC test at admission in hospitalized older adults.

A methodological (cross-sectional) study with 148 older adults hospitalized in a public hospital in the Federal District, Brazil. Data on age, sex, body mass index (BMI) and engagement in regular physical exercise were collected for sample characterization. The main variable was muscle strength, measured by handgrip dynamometry and the Medical Research Council (MRC) scale. The data were analyzed using descriptive statistics, Spearman's correlation and the Kappa statistic (α=5%).

of the older adults included in the study, 41.9% were women, 79.7% were sedentary, aged 60 to 101 years (median = 70 years), taking 5.14 continuous use drugs, with an average BMI of 26.22 Kg/m². The average handgrip strength was 23.83 Kgf (SD=8.45) and the MRC score was 54.94 points (SD=5.709). Muscle weakness was identified in 60.8% of participants via handgrip dynamometry and in 10.8% via the MRC. There was a moderate correlation (r=0.646; p<0.001) between handgrip strength and MRC score and weak agreement (K=0.122; p=0.004) between the muscle weakness diagnoses of the two instruments.

Unlike the muscle weakness diagnoses obtained by handgrip strength assessment, a minority of participants exhibited muscle weakness when evaluated by the MRC scale, displaying weak agreement between the measures investigated despite the moderate correlation.

These results suggesting that handgrip strength and MRC be used in sequence, with dynamometry as a rapid initial screening tool that, when abnormal, should be followed by the MRC to specifically identify the typical distribution of muscle weakness. Information on muscle strength from hospital admission to discharge can provide specific starting points for personalized interventions to combat sarcopenia and prevent functional decline in the hospital setting and after acute hospitalization.