Modified sphygmomanometer test for the assessment of strength of the trunk, upper and lower limbs muscles in subjects with subacute stroke: reliability and validity.

Background: Limitations in activities have been related to weakness of the upper limbs (UL), lower limbs (LL) and trunk muscles after stroke. Therefore, the measurement of strength after stroke becomes essential. The Modified Sphygmomanometer Test (MST) is an alternative method for the measurement of strength, since it is cheap and provides objective values. However, no studies have investigated the measurement properties of the MST in sub-acute stroke.

Aim: To investigate the test-retest and inter-rater reliabilities and criterion-related validity of the MST for the measurement of strength of the UL, LL, and trunk muscles in subjects with sub-acute stroke, and verify whether the number of trials would affect the results.

Design: Diagnostic accuracy.

Setting: Local community, out-patient clinics, and university laboratory.

Population: Sixty- five subjects with sub-acute stroke (62±14 years) participated of the present study.

Methods: The strength of 36 muscular groups was measured with the MST and dynamometers (criterion standard). To investigate whether the number of trials would affect the results, analysis of variance was applied. For the test-retest and inter-rater reliabilities and criterion-related validity of the MST, intra-class correlation coefficients (ICC), Pearson correlation coefficients, and coefficients of determination were calculated.

Results: Similar results were found for all muscular groups and number of trials (0.01≤F≤0.14; 0.87≤p≤0.99) with significant and adequate values of test-retest (0.57≤ICC≥0.98) (exception: first trial of the non-paretic ankle dorsiflexors) and inter-rater (0.50≤ICC≥0.99) (exception: non-paretic ankle plantar flexors) reliabilities and validity (0.70≤r≥0.95; p≤0.001). The values obtained with the MST were good predictors of those obtained with the dynamometers (0.54≤r2≤0.90).

Conclusions: In general, the MST showed adequate reliabilities and criterion-related validity for measuring strength of subjects with sub-acute stroke, and only one trial, after familiarization, provided adequate values.

Clinical Rehabilitation Impact: The MST can be used by health professionals within several clinical contexts to objectively measure strength of the UL, LL, and trunk muscles in subjects with sub-acute stroke. Besides providing objective, reliable, and valid strength measures, the MST is also feasible. The aneroid sphygmomanometer used for the MST assessment is portable, easily found worldwide, and commonly acquired by health professionals. Furthermore, its adaptation is simple, reversible, and cheap.