Effects of trunk stability on isometric knee extension muscle strength measurement while sitting

Abstract

[Purpose] This study aimed to investigate the effect of trunk stability on isometric knee extension muscle strength measurement while sitting by performing simultaneous measurements with a handheld dynamometer (HHD) and an isokinetic dynamometer (IKD) in the same seated condition. [Subjects and Methods] The subjects were 30 healthy volunteers. Isometric knee extension muscle strength was simultaneously measured with a HHD and an IKD by using an IKD-specific chair. The measurement was performed twice. Measurement instrument variables and the number of measurements were examined by using the analysis of variance and correlation tests. [Results] The measurement instrument variables and the number of measurements were not significantly different. The correlation coefficients between the HHD and IKD measurements were ≥0.96. [Conclusion] Isometric knee extension muscle strength measurement using the HHD in the sitting position resulted in a lower value than that using the IKD, presumably because of the effect of trunk stability on the measurement. In the same seated posture with trunk stability, no significant difference in measurement values was observed between the HHD and IKD. The present findings suggest that trunk stability while seated during isometric knee extension muscle strength measurement influenced the HHD measurement.

Validity and reliability of isometric knee extension muscle strength measurements using a belt-stabilized hand-held dynamometer: a comparison with the measurement using an isokinetic dynamometer in a sitting posture

“…These previous studies have suggested that measurement value of IKD is higher than that of HHD, and HHD and IKD are related although the conditions of measurement position for comparing are not similar. In contrast, in the same sitting condition with trunk fixation, no significant difference was reported between the measurements obtained using HHD and IKD 22) . The difference between the measurement values of HHD and IKD was considered to be attributed to the different measurement conditions with respect to the presence or absence of trunk fixation.…”

“…However, a previous study on validity was conducted using different measurement postures or different sitting conditions. In the same postural setting with the participant in the sitting position fixed with straps, Hirano et al 22) reported that the measurement values between the measuring equipment was not significantly different and that the HHD and IKD were correlated (r=0.96 to 0.98, p<0.01).…”

Concurrent validity of a fixated hand-held dynamometer for measuring isometric knee extension strength in adults with congenital heart disease

“…The problem with the HHD measuring lower peak forces than other methods have also been shown in comparison with an isokinetic dynamometer [38,39], however, this is not a universal finding [27,40]. It could be that the difference between a HHD and an isokinetic dynamometer is affected by trunk stability, since when stabilising the trunk during a HHD measurement, the methods seem to measure the same [24]. Within the healthy population, similar to our findings, fixating the HHD against the bunk leg instead of the participant's leg ensures that the results of the fixated HHD and an isokinetic dynamometer, or in our case a load cell, will not statistically differ.…”

“…The make method can be done either with manual resistance or with fixation of the HHD. Even though manual resistance is the most utilised way of using a HHD [19,22,23], the reliability and validity of this technique compared to an isokinetic dynamometer or to a load cell vary markedly between studies [12,19,24]. This could, at least partly, be explained by a lack of a standardised test procedure [19] but it could also be a result of difficulties to manually resist the force produced by the tested limb.…”

Evaluation of bilateral force deficit in shoulder flexion using a handheld dynamometer in healthy subjects

“…However, because these dynamometers are extensive and too large, use in sports-medicine practices are limited 1 ) . In recent years, the validity and reliability of simple handheld dynamometers have been investigated for alternative measurements of muscle strength 2 , 3 ) . Significant correlation coefficients between the values obtained using handheld dynamometers and isometric dynamometers have been reported 2 , 4 , 5 ) .…”