Circadian Variations in the Kinematics of Handwriting and Grip Strength
- 1 January 2009
- journal article
- research article
- Published by Taylor & Francis Ltd in Chronobiology International
- Vol. 26 (3), 576-594
- https://doi.org/10.1080/07420520902896590
Abstract
The present study determined whether the motor process of handwriting is influenced by a circadian rhythm during writing tasks of high everyday relevance and analyzed the relationship to the circadian rhythm of grip strength. Ten healthy young male subjects underwent a 40 h sleep‐deprivation protocol under constant routine conditions. Starting at 09:00 h, subjects performed three handwriting tasks of increasing perceptual‐motor complexity (writing a sentence, writing one's signature, and copying a text for 3 min) and assessed grip strength of both hands every 3 h. Handwriting performance was analyzed by writing speed, writing fluency, script size, break times, and pen pressure. The handwriting tasks revealed a coincident circadian rhythm for the frequency of handwriting as a measure of movement speed, with slowest writing speed at 03:16 h. A weak effect of task complexity was evident for the non‐writing episodes: while copying a text, break times were influenced by a circadian rhythm, whereas during sentence writing, the non‐writing episodes remained constant. The circadian rhythm of grip strength paralleled the time course of motivation ratings, with least motivation and weakest grip strength around 06:00 h concurrently for both hands. The rate of force production also displayed circadian rhythmicity and sharply decreased with the onset of melatonin secretion. Neither grip strength nor the kinematics of handwriting was influenced by sleep deprivation; only the level of the force rate was decreased the second day. The results show a clear circadian rhythm in the speed of handwriting and grip strength.Keywords
This publication has 36 references indexed in Scilit:
- Circadian Rhythms and Their Association with Body Temperature and Time Awake when Performing a Simple Task with the Dominant and Non‐Dominant HandChronobiology International, 2008
- An oscillatory neuromotor model of handwriting generationInternational Journal on Document Analysis and Recognition (IJDAR), 2007
- Age‐Related Differences in Daily Attention Patterns in Preschool, Kindergarten, First‐Grade, and Fifth‐Grade PupilsChronobiology International, 2007
- Diurnal Variation in Temperature, Mental and Physical Performance, and Tasks Specifically Related to Football (Soccer)Chronobiology International, 2007
- Circadian Rhythms in Sports Performance—an UpdateChronobiology International, 2005
- Effect of time of day on force variation in a human muscleMuscle & Nerve, 1999
- Circadian rhythms in human performance and mood under constant conditionsJournal of Sleep Research, 1997
- Sources of variation in back and leg dynamometryErgonomics, 1994
- Subjective and Objective Sleepiness in the Active IndividualInternational Journal of Neuroscience, 1990
- Diurnal and Sequential Grip Function in Normal Subjects and Effects of Temperature Change and Exercise of the Forearm on Grip Function in Patients With Rheumatoid Arthritis and in Normal ControlsScandinavian Journal of Rheumatology, 1982