Dynamometry for the measurement of grip, pinch, and trunk muscles strength in subjects with subacute stroke: reliability and different number of trials

Abstract

BackgroundMuscle strength is usually measured in individuals with stroke with Portable dynamometers (gold standard). However, no studies have investigated the reliability, the standard error of measurement (SEM) and the minimal detectable difference (MDD95%) of the dynamometry for the measurement of hand grip, pinch grip and trunk strength in subjects with subacute stroke.Objective1) To investigate the intra and inter-rater reliability, the SEM and the MDD95% of the portable dynamometers for the measurement of grip, pinch and trunk strength in subjects with subacute stroke, and 2) to verify whether the use of different number of trials (first trial and the average of the first two and three trials) affected the results.Method32 subjects with subacute stroke (time since stroke onset: 3.6 months, SD=0.66 months) were evaluated. Hand grip, 3 pinch grips (i.e. pulp-to-pulp/palmar/lateral) and 4 trunk muscles (i.e. flexors, extensors, lateral flexors and rotators) strength were bilaterally assessed (except trunk flexors/extensors) with portable dynamometry by two independent examiners over two sessions (1-2 weeks apart). One-way ANOVAs and intraclass correlation coefficients (ICC2,k) were used for analysis (α=0.05). SEM and MDD95% were also calculated.ResultsFor all muscular groups and sources of outcome values, including one trial, after familiarization, similar results were found (0.01≤F≤0.08; 0.92≤p≤0.99) with significant and adequate values of intra-rater (0.64≤ICC≤0.99; 0.23≤95%CI≤0.99) and inter-rater (0.66≤ICC≤0.99; 0.25≤95%CI≤0.99) reliability. SEM and MDD95% were considered low (0.39≤EPM≤2.21 Kg; 0.96≤MMD95%≤6.12 Kg) for all outcome scores.ConclusionOnly one trial, following familiarization, demonstrated adequate intra-rater and inter-rater reliability of the portable dynamometers for the measurement of hand grip, pinch grip and trunk strength in subjects with subacute stroke.

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

“…Previous studies that investigated whether dynamometry strength measures based upon various numbers of trials were statistically different, found similar results for the following muscle groups: grip; pulp‐to‐pulp, palmar, and lateral pinch; and trunk flexors/extensors, lateral flexors, and rotators of individuals with sub‐acute (.92 ≤ P ≤ .99) and chronic (.85 ≤ P ≤ .99) stroke. In addition, Coldham et al reported that only a single trial of grip strength, measured with a dynamometer, in healthy individuals and in individuals who had undergone orthopedic surgery, is as reliable as the mean and the best value of 3 trials .…”

“…Consequently, there is less chance for the regression toward the mean phenomenon to occur . Because hand‐held dynamometers have shown to provide reliable measures of strength of the upper and lower limb muscles of individuals with stroke (0.58 ≤ correlation coefficient ≤ 0.99) , this may justify the findings; that is, similar values were provided by different scoring methods.…”

“…Because hand-held dynamometers have shown to provide reliable measures of strength of the upper and lower limb muscles of individuals with stroke (0.58 ≤ correlation coefficient ≤ 0.99) [3][4][5][6], this may justify the findings; that is, similar values were provided by different scoring methods. Previous studies that investigated whether dynamometry strength measures based upon various numbers of trials were statistically different, found similar results for the following muscle groups: grip; pulp-to-pulp, palmar, and lateral pinch; and trunk flexors/extensors, lateral flexors, and rotators of individuals with sub-acute (.92 ≤ P ≤ .99) [5] and chronic (.85 ≤ P ≤ .99) [6] stroke. In addition, Coldham et al reported that only a single trial of grip strength, measured with a dynamometer, in healthy individuals and in individuals who had undergone orthopedic surgery, is as reliable as the mean and the best value of 3 trials [14].…”

“…This device is portable, so it may be used within clinical settings, is easy to use, provides objective measures of strength of various muscle groups, and is sensitive for detecting changes over time [2][3][4]. In addition, it provides valid and reliable measures of strength in individuals with sub-acute and chronic stroke [2][3][4][5][6].…”

Does grip strength predict lower limb global strength in subjects with stroke?

“…Considering that the association between grip strength and lower-limb muscle function has been proved to be a relevant parameter to be investigated in older adult population [17], investigating this association in different populations with muscle weakness and disabilities becomes necessary. In this context, post-stroke individuals must be considered, since this population commonly present lower thresholds for muscle fatigue as well as muscle weakness [12,19]. Thus, a fast and objective measure such as grip strength would optimize the clinical evaluation process by informing about lower-limb global strength.…”