• J Clin Monit Comput · Feb 1999

    Randomized Controlled Trial Clinical Trial

    The effect of maintaining a constant preload or a constant degree of thumb abduction in the isometric twitch force of the thumb.

    • G van Santen, E Otten, and J M Wierda.
    • Research Group for Experimental Anesthesiology and Clinical Pharmacology, University of Groningen, Groningen, The Netherlands.
    • J Clin Monit Comput. 1999 Feb 1; 15 (2): 93-102.

    ObjectiveTo investigate the effects of maintaining a constant preload and of maintaining a constant degree of thumb abduction on the isometric twitch force during mechanomyography of the thumb, we monitored neuromuscular function in patients anaesthetized without the use of a neuromuscular blocking agent. In addition, we studied the relationship between the degree of thumb abduction, twitch force and preload.MethodsFourteen patients were divided randomly into two groups, determining the sequence of the experiments in respect of correcting the preload and maintaining a constant degree of abduction after allowing the twitch forces to stabilize. Both experiments lasted 15 minutes. In both groups the relationship between the degree of thumb abduction, twitch force and preload was studied.ResultsWe found a progressive increase in twitch force both with (6.6%; CI: 3.7-9.3%; p < 0.001) and without (1.9%; CI: 0.4-3.5%; p = 0.020) continuous correction of the thumb preload. A significant greater increase in twitch force was seen when the preload had been corrected than when it was not (4.7%; CI: 0.8-8.7%; p = 0.023). In addition, both twitch force and preload appeared to depend on the degree of thumb abduction both before and at the time of measurement.ConclusionsChanges in length of the contracting muscle fibres and creep phenomena in the connective tissue of the muscles, both leading to changes in the sarcomere length of the muscle fibres, may explain the observations in this study. In general, a stabilized preload at a constant degree of abduction seems to be required in order to obtain a stable twitch force.

      Pubmed     Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…