• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.4
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• pp.46-53
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• 2002

Push-pull strength has been found to be associated with various work factors such as height, distance, repetition, duration, posture and individual factors. Therefore, this study was performed to investigate the effect of various work factors on push-pull strength and muscle recruitment pattern. Work factors were consisted of grip height(elbow, shoulder), grip distance(100%, 50%, and 25% of maximum grip distance) and shoulder angle(neutral($90^{\cire}$), and abduction($45^{\cire}$, $0^{\cire}$)) during sitting work. The results showed that the normalized strength and EMG value were higher at the elbow height than the shoulder height, and increased with grip distance and shoulder adduction. The results of ANOVA showed that there was significant difference on muscle recruitment patterns among the task conditions. Therefore, it is necessary to consider work factors as well as strength to prevent workers from work-related injuries.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.41-47
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• 2009

The purpose of this study, during the lifting task was researching the difference and a relationship between the ground reaction force and the grip strength by change of position. After grip strength has measured in symmetry position and asymmetry position at 45cm and 75cm of height of hand, ground reaction force was measured by same attitude lifting wooden box. We analyzed the difference of grip strength and ground reaction force in each position change. The results of grip strength, the grip strength of both hand were significant difference that in study subject symmetry and asymmetry position (p<0.01). The results of symmetry lifting task, the study subjects was significant difference of the ground reaction force difference by height (p<0.05). Asymmetry lifting task was significant difference of ground reaction force difference by direction of rotation was changed (p<0.01). The result of it will rotate with non-dominant hand side of lifting tasks from height 75cm where it easily maintains a balance possibility and decreasing the load of the hand. Therefore, from the workshop in the work people, it will be between the height 75cm and non-dominant hand side of trunk rotatory direction in the lifting tasks. Future study is necessary researched about the change of grip strength when the height of the hand is higher, and the difference of the ground reaction force when the change of weight.

• PNF and Movement
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• v.20 no.1
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• pp.125-134
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• 2022

Purpose: The aim of this study was to establish an association between grip strength and gait variability in the elderly. Methods: The participants in this experiment (n = 20) were aged 65 or older. Power grip and lateral pinch forces were obtained in grip strength tests, and spatiotemporal gait parameters were collected from IMU sensors during 6 min actual walking to test the gait of participants. The collected gait parameters were converted to coefficient of variation (CV) values. To confirm the association between grip strength and gait variability, a partial correlation analysis was conducted in which height, weight, and gait speed were input as controlling variables. Results: Grip power showed a significant negative correlation with the stride length CV (r = -0.52), and the lateral pinch force showed a significant negative correlation with the stance CV (r = -0.65) and swing CV (r = -0.63). Conclusion: This study reveals that gait variability decreases as grip strength increases, although height, weight, and gait speed were controlled. Thus, grip strength testing, a simple aging evaluation method, can help identify unstable gait in older adults at risk of falling, and grip strength can be utilized as a non-invasive measurement method for frailty management and prevention.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.13-23
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• 2006

Grip strength provides a quick and objective index of the functional integrity of the upper extremities. It is widely used as an assessment measure in physical and rehabilitation medicine. In this study, maximum voluntary grip strength of 20 college students wearing 5 different gloves were measured using Jamar hand dynamometer. The results show that maximum voluntary grip strength was generally reduced when wearing gloves as compared to bare-handed. More specifically, the grip strength was highest when wearing PVC coated glove or bare-handed and getting lowered as wrist band, rubber, leather, and cotton glove in these order. Depending on the measuring posture of grip strength, shoulder height with arm extended forward was higher than the elbow was flexed 90 degree. Moreover, subjects' demographic factors and hand dimensions were not closely related to the grip strength. It is thus recommended that the proper glove should be provided to reduce the negative consequences including dropping a tool, poorer control of a tool. lower quality work, and increased muscle fatigue and in turn to increase the user safety and satisfaction.

• Journal of the Ergonomics Society of Korea
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• v.16 no.1
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• pp.73-83
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• 1997

It is improtant to get accurate information about the grip strength for designing ergonomic grips and handles. It has been known that the excessive and repetitive use of grip force and unnatural posture of the wrist may cause cumulative trauma disorders (CTDs) such as carpal tunnel syndrome, tendrome, tendonitis, DeQuervan's disease, etc. In this paper we have measured the grip strength for sitting and standing posture for Korean adults ; 114 males and 105 females aged from the 20's to above the 50's. And this paper performed statistical analysis for deriving characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum grip strength posture is exerted under standing posture with the elbow in full extension (180 .deg. ) for both males and females (2) There is significant difference among posture, sex and right and/or left handedness (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has corre- lations with the age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist, and breadth of wrist for males.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.238-243
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• 1996

Grip strength is a very important basic data for ergonomic design of hand tools, grips, handles and etc.. Excessive grip strength is contineously exerted to handle the machines or tools, it might cause a musculoskeletal disorder such as cumulative trauma disorders. Capal tunnel syndrome is a typical nerve disorder anomg CTDs. In this paper we have measured the grip strength under sitting and standing posture for Korean adults ; 113 male and 105 female aged from 20' to the above 50' . And this paper performed statistical analysis for driving out characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum girp strength is exerted under standing posture with the elbow in full extension(180 .deg. ) for both of male and female (2) There is significant difference in posture, sex and right left hand (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has a correlation with age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist and breadth of wrist for male

• Journal of Society of Occupational Therapy for the Aged and Dementia
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• v.12 no.2
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• pp.19-28
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• 2018

Objective : The aim of current investigation was to standardize the grip strength of elders and to examine the correlation between grip strength, anthropometric parameters, depression and quality of life. Method : The researchers used Korea national health and nutrition examination surveys (2016) for analysis and analyzed the data of 919 elders who had completed the screening test among right-handed elderly without activity limitation. The researchers classified the age of the elders as 65~69, 70~74, 75~79, and 80 years old for standardization of grip strength. Anthropometric parameters are height, weight, body mass index, and waist circumference. Depression was measured by PHQ-9(Patient Health Questionnaire-9) and quality of life was assessed by EQ-5D. Result : The ratio of right handedness of the elderly was 87.8%, left handed 4.9%, and both handles 5.7%. In the standardization and correlation analysis, the grip strength decreased with age (p<.01, r=-.308~-.305). The grip strength showed a strong correlation with height (p<.001, r=.747~.741). There was a significant correlation between depression (p<.01, r=-.172~-.163) and quality of life (p<.01, r=.285~.267). Conclusion : The findings of this investigation suggest that height, depression, and quality of life need to be considered when assessing the level of grip strength in the elderly.

• Journal of Korean Physical Therapy Science
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• v.20 no.1
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• pp.43-49
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• 2013

Background and purpose : The shoulder joints permit the greatest mobility of any joint area carries out the important function of stabilization for hand use. Research has now shown that grip strength has proven to be a reliable indicator for quality of life at an older age. The purpose of this study was to investigate the effects of testing posture and shoulder position on grip strength for repetitive gripping task. Methods : Forty(20male, 20female) college adult volunteers with no known shoulder dysfunction participated subject in two testing posture(sitting and standing) and three positions with shoulder flexion: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}$ flexion (3) shoulder $180^{\circ}$ flexion. The paired t-test was used to determine any significant difference in grip strength between the testing posture and shoulder position. Results : The higher grip strength gained in the sitting with the shoulder $180^{\circ}$ flexion and the higher grip strength gained in the standing with the shoulder $180^{\circ}$ flexion. The second experiment showed that the grip strength was significant for sitting, standing position of shoulder $0^{\circ}$ flexion( p<0.05). Grip strength goes up as increase height and weight. Conclusion : These findings demonstrate that the theory does not fit with, because of the influence of gravity, a measure from the shoulder joint is the most high, $0^{\circ}$. And sitting posture and stance in the grip of a difference when compared SIT $0^{\circ}$ and standing position $0^{\circ}$ significant difference in indicated but, $90^{\circ}$ and $180^{\circ}$ in the sitting position and stance in the grip of the difference was not significant difference. To demonstrate the universality of this study's results, future studies should have a larger and more subject as well as a more even distribution of male and female subject. Therefore future research is needed to refine the definition and identify optimal methods of measuring this grip strength.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.449-457
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• 2001

This study was performed to show change of fat-free mass(FFM), representing mostly the muscle mass change, and muscle strength with increasing age, and relationship between dietary, exercise behaviors and FFM in healthy middle-and old aged women who are of age over 55 years. The FFM and correspondingly hand grip strength showed significant positive correlation with age. But concentration of serum albumin showed no significant relationship with age. The subjects were categorized into groups according to FFM tertile. The anthropometry such as weight, BMI, fat mass, circumferences of waist and hip, WHR, and hand grip strength decreased significantly in the lowest FFM group. But the albumin level showed no change according to FFM level. The FFM showed significant correlation with nutrient intakes such as energy, carbohydrate, protein, Fe, P, Ca. No association, however, was shown with exercise behavior probably because of no case with resistance exercise habits. The variance of FFM was explained 55.2% by height and carbohydrate intake. The variance of height-adjusted FFM could be explained only 16.2% by intake amount of carbohydrate. In conclusion, the decrease of FFM may cause to reduce muscle strength in female elderly. The increasing nutrient intakes were associated with the increased FFM and may protect from risk of sarcopenia. However, only the carbohydrate intake could influence independently the FFM in middle- and old-aged women. The FFM has no association with endurance exercise habits. (Korean J Nutrition 34(4) : 449∼457, 2001)

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.209-213
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• 1997

Manual lifting techniques are commonly defined in terms of the postures adopted at the start of the lift. Quantitative definition is problematic, however, because the absolute joint angles adopted to lift an object are influenced by task parameters, such as the initial height of the load. The main objective of this study is to investigate the grip strength of the both hands at the initial lifting points. The survey is conducted by measuring the compression force, anthropometric data and grip strength at the lifting postures for the subjects(n=50) who is assigned to their job as usual. The experiment is peformed at the four lifting postures which involving the combination of two horizontal factors(H1 : 35 cm, H2 : 55 cm) and two vertical factors(V1 : 20~80 cm, V2 : 47~102 cm). The analysis result of lifting posture indicated that each H1-V1, H2-V1 combinations are about 60$^{\circ}$ and each H1-V2, H2-V2 combinations are about $30^{\circ}$. There are significant differences on grip strength between $60^{\circ}$ and $30^{\circ}$ stooped posture. The results of this study can be provided a method defining lifting postures at the minimum grip strength. Also, it is eliminated a hazard of the injuries which are cumulative trauma disorders(CTDs) and back pain, increased a productivity and improved a welfare of workers.