A Single Trial May Be Used for Measuring Muscle Strength With Dynamometers in Individuals With Stroke: A Cross‐Sectional Study

BACKGROUND: The mean of 3 trials is commonly employed to report measures of muscle strength after a stroke. However, consistent and reliable results have been found for single trial dynamometric measures of grip, pinch, and trunk strength in individuals with stroke. Nevertheless, no studies were found that investigated whether only a single trial could be used for the assessment of the strength of both the upper and lower limb muscles. OBJECTIVE: To determine the best scoring method (one vs the means of 2 or 3 trials) to measure the strength of the upper and lower limb muscles in individuals with sub-acute and chronic stroke. DESIGN: Cross-sectional observational study. SETTING: Research laboratory, participants' homes, and community-based settings. PARTICIPANTS: Fifty-five individuals at the sub-acute (mean age: 61 ± 13 years; 3.7 ± 0.7 months poststroke) and 59 at the chronic poststroke phases (mean age: 57 ± 130 years; 90 ± 71 months poststroke). MAIN OUTCOME MEASUREMENTS: Bilateral maximum isometric strength measures of the shoulder, elbow, and wrist flexors/extensors; shoulder abductors; hip, knee, and ankle flexors/extensors; and hip abductors were obtained with a hand-held dynamometer. METHODS: After familiarization, 3 trials of maximal isometric strength were obtained for all evaluated muscle groups. One-way analysis of variance was used to compare the results obtained with the first vs the means of 2 and 3 trials for all the assessed muscle groups. RESULTS: The values provided by the different scoring methods were similar for all evaluated muscle groups in individuals with sub-acute (.68 ≤ P ≤ .99) and chronic (.69 ≤ P ≤ .99) stroke. CONCLUSIONS: A single trial, after familiarization, may be used for measuring the strength of the upper and lower limb muscles with hand-held dynamometers in individuals with sub-acute and chronic stroke. This increases the clinical applicability of hand-held dynamometers for strength measurement, as it reduces the assessment burden placed on the participants and therapists. LEVEL OF EVIDENCE: III.