title: Reliability and gender differences of static explosive grip parameters based on force-time curves.
abstract: OBJECTIVE
  The purpose of this study was to examine the reliability and gender differences of static explosive grip (SEG) parameters based on force-time curves.
  
  
  METHODS
  
  
  
  METHODS
  data were collected from 2 trials of SEG tests on the same day and 2 trials 1 week later.
  
  
  METHODS
  50 healthy young males (21.2+/-1.57 yrs) and females (20.1+/-1.18 yrs) participated in this study.
  
  
  METHODS
  12 variables based on factors such as time-course of force, average force, integrated area, maximal rate of force development, the product of force and inclination and exponential function of force development (EXP-M) were selected as force-time parameters in SEG testing.
  
  
  RESULTS
  A significant reliability was obtained for all force-time parameters except the time to 90% of maximal grip strength (MAX), with the reliability of integrated area, average force, maximal rate of force development (DFmax), and the product of force and inclination being particularly high (ICC=0.633-0.930 for the same day, ICC=0.612-0.828 for different days). There were gender differences for all parameters except the time to MAX and EXP-M (p<0.05). In addition, many of the correlation coefficients between parameters were high, particularly for males. The average force, integrated area for 1 sec, and the product of force and inclination during the developmental phase significantly correlated with MAX in both males and females. The ratio between males and females in these force-time parameters was smaller than that of MAX (71.3%).
  
  
  CONCLUSIONS
  It is considered that these parameters are dependent on the speed of muscle contraction. These results suggest that the evaluation parameters, such as average force, integrated area, the product of force and inclination, and maximal rate of force development are useful for evaluating static explosive grip.
authors.affiliation: Department of Physical Education, Kanazawa University, Kanazawa, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Demura
authors.forename: S
authors.initials: S
authors.lastname: Yamaji
authors.forename: Y
authors.initials: Y
authors.lastname: Nagasawa
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: M
authors.initials: M
authors.lastname: Minami
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D015203:Reproducibility of Results; D012737:Sex Factors; D013223:Statistics as Topic; D013647:Task Performance and Analysis; D013995:Time; D014894:Weights and Measures / Q000592:standards*