• 대한인간공학회지
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• 제24권2호
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• pp.45-49
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• 2005

The FSA(Force Sensitive Application) system measures hand force by using force resistance sensors. Compared to conventional hand force measurement systems such as Lafayette hand dynamometer and Jamar hydraulic hand dynamometer, the FSA system can be applied to analyze use of hand forces while the hand is manipulating objects for a task, However, the measurement performance of the FSA system has not been objectively evaluated. The present study tested the FSA system in terms of stability, repeatability, accuracy, and linearity. It is shown that the FSA system has good stability (CV$\leq$0.02) and linearity($R^2$=0.82), but has low repeatability(CV=$0.11{\sim}0.19$) and accuracy(22% of underevaluation on average). This performance result indicates that measurements from the FSA system should be used for relative comparison rather than for absolute comparison.

• Archives of Plastic Surgery
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• 제40권1호
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• pp.52-56
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• 2013

Background Measuring grip and pinch strength is an important part of hand injury evaluation. Currently, there are no standardized values of normal grip and pinch strength among the Korean population, and lack of such data prevents objective evaluation of post-surgical recovery in strength. This study was designed to establish the normal values of grip and pinch strength among the healthy Korean population and to identify any dependent variables affecting grip and pinch strength. Methods A cross-sectional study was carried out. The inclusion criterion was being a healthy Korean person without a previous history of hand trauma. The grip strength was measured using a Jamar dynamometer. Pulp and key pinch strength were measured with a hydraulic pinch gauge. Intra-individual and inter-individual variations in these variables were analyzed in a standardized statistical manner. Results There were a total of 336 healthy participants between 13 and 77 years of age. As would be expected in any given population, the mean grip and pinch strength was greater in the right hand than the left. Male participants (137) showed mean strengths greater than female participants (199) when adjusted for age. Among the male participants, anthropometric variables correlated positively with grip strength, but no such correlations were identifiable in female participants in a statistically significant way. Conclusions Objective measurements of hand strength are an important component of hand injury evaluation, and population-specific normative data are essential for clinical and research purposes. This study reports updated normative hand strengths of the South Korean population in the 21st century.

• 대한인간공학회지
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• 제30권3호
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• pp.381-387
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• 2011

Objective: The aim of this study was to investigate the maximal grip strength for the combinations of resting time and trial and to provide guideline of resting time for the maximum gripping task associated with the number of trials. Background: Despite many previous researches for the maximal grip strength, few studies have considered the effect of both trials and rest time on the maximum grip strength. Methods: A total of thirty subjects participated in the study. The average of maximum grip strength was measured using JAMAR hydraulic hand dynamometer. The testing position was same as the position recommended by the American Society of Hand Therapists. The between-subject experimental design has been conducted in this study. Trials(1~20 trials) and rest time(2, 3, and 4min) were considered as independent variables, and the maximum grip strength was considered as dependent variable, respectively, in this study. Results: According to the result of the number of trials, the maximal grip strength decreased gradually as the number of trials increased. The ANOVA result showed that the main effect was significant for both resting time(p<.0001) and trial(p<.0001), and the interaction was significant(p<0.0086). Conclusions: The maximal grip strength decreased gradually as the number of trials increased. Thus, basic guideline of resting time was suggested for the number of trials of maximal grip strength tests in this study.

• 대한통합의학회지
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• 제1권2호
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• pp.23-35
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• 2013

Purpose : We intend to make the study date for an effect of therapy by comparing the functional level both before and after conducting handwriting training and strength training as a part of treatment to improve muscle strength and function of the patient's non-dominant hand. Method : 8 subjects in writing training group conducted hand writing training 30 minutes at once and three times a week for 4 weeks in total 12 times, and 8 subjects in muscle training group conducted muscle training program of putty and Rolyan ergonomic hand exerciser for 15 minutes respectively in sum up 30 minutes at once and three times a week for 4 weeks in total 12 times. 8 subjects in control group are not applied any training for 4 weeks. Results : It was much more effective in handwriting training than muscle strength training by Grooved pegboard because this study showed the speed decrease from 67.11 to 58.26 seconds in handwriting compared with muscle strength training which showed 5.22 seconds decrease from 67.54 to 62.32(P<.05). It showed about 1.34 muscle strength improvement from 6.60 to 7.94 in handwriting training and 0.92 improvement of muscle strength from 7.04 to 7.96 in muscle strength training by 3-jaw chuck pinch, so handwriting training was more effective(P<.05). It showed 11.58 seconds decrease in handwriting training from 26.62 to 18.01 seconds and 10.93 seconds decrease from 27.43 to 16.50 seconds in muscle strength training, so it was significantly shortened both in handwriting and muscle strength training(P<.05). Conclusion : Dexterity, muscle strength, and handwriting ability of non-dominant hand could improve both the handwriting training and the muscle strength training.