• Physical Therapy Rehabilitation Science
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• v.5 no.2
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• pp.95-100
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• 2016

Objective: The purpose of this study was to investigate effects of hand grip strength on the muscle activation of shoulder joint in breast cancer patients. Design: Cross-sectional study. Methods: Ten breast cancer patients who agreed to active participation were included. These patients were operated with either conservative surgery or segmental mastectomy, and then were treated with radiation therapy and chemotherapy. The activity of the upper trapezius, lower trapezius, supraspinatus and serratus anterior muscle were measured using surface electrodes during 4 hand gripping tasks (lowered their arms in standing position, 0%, 30%, and 50% of maximum voluntary contraction) in the scapular abduction plane. Results: The results were analyzed using a one-way repeated measures ANOVA. There was a significant difference in the lower trapezius and supraspinatus muscles according to grip strength, lower trapezius and supraspinatus muscles showed significantly difference according to grip strength (p<0.05). The result of the muscle activation according to hand strength (0%, 30%, and 50%) it showed a significant difference between the upper trapezius and supraspinatus in 0% grip strength (p<0.05). In addition, it did not show a significant difference between muscles in 30%, 50% hand strength. Conclusions: This study showed an increase in shoulder muscle activation with increasing hand grip strength with the upper trapezius muscle being more activated than other muscles in 0% grip strength. The finding of this study suggests usefulness for development of preventative measures and rehabilitation strategies for increasing shoulder motor function in patients with breast cancer.

• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.413-423
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• 2016

Objective:The aims of this study are to understand the effects of task (pushing, pulling, and clockwise and counter clockwise twisting) direction on the maximal output and their grip forces and to explore the relationship between the maximal output and the grip forces. Background: Knowing the normative maximal grip force is not enough to design a good hand tool. The industrial designers should understand the required grip forces in various motions toward a specific direction to make an effective and efficient hand tool. Method: Eighteen healthy volunteers participated in the series of isometric maximal output force tests. A custom-made force measuring equipment collected the output and the grip forces for three seconds. Force measurements along the vertical, coronal and sagittal axes were randomly repeated three times. Results: The pulling was strongest and the pushing was weakest in all directions. The effect of motion on the output forces varied in different directions. The corresponding grip force increased in the order of pushing, pulling, clockwise twisting, and counter clockwise twisting in all directions. The maximal output and their grip forces were highly correlated but the relationship was affected by motion and direction. The regression coefficient was greatest in pulling and smallest in clockwise twisting. Conclusion: The effect of motion on the output forces varied in different directions. The maximal output and their grip forces were correlated but the relationship was affected by motion and direction. Application: Findings of this study can be valuable information for industrial designers to develop more productive hand tools and work stations to help preventing the musculoskeletal disorders at work.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.553-563
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• 2014

Objective: The purpose of this study was to evaluate the effect of gender (male, female) and grip spans (45, 50, 60, 70, 80mm) on total grip strength, resultant force, finger force and subjective discomfort rating. Background: In order to prevent musculoskeletal disorders, studies of hand tools need to be preceded based on grip strength, finger force, and subjective discomfort rating. However, experimental apparatus using tools such as pliers that reflect the actual work place was almost non-existent. Method: Fifty-Two (26 males and 26 females) participants were recruited from the student population. In this study, a pair of revised pliers, which can change grip span from 45 to 80mm was applied to estimate total grip strength, resultant force and individual finger forces. All participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: There were significant differences of total grip strength, resultant force, individual finger forces and subjective discomfort rating according to grip span. The lowest total grip strength was obtained from the grip span of 80mm for both genders. For resultant force, the highest resultant force was exerted at grip spans of 50, 60 and 70mm for females and 50 and 60mm for males. The lowest subjective discomfort rating was observed in the 50mm for both genders. Conclusion: Based on the result, 50mm and 60mm grip spans which provide the highest force and lowest discomfort rating might be recommendable for the male and female pliers users. Application: The findings of this study can provide guidelines on designing a hand tool to help to reduce hand-related musculoskeletal disorders and obtain better performance.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.822-832
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• 2018

Objective To determine the socio-demographic, psychologic, hematologic, or other relevant factors associated with hand grip strength in Korean farmers. Methods A total of 528 healthy Korean farmers were enrolled. Hand grip strength was measured in both hands using a hydraulic dynamometer. Socio-demographic characteristics were assessed and anthropometric measurements were obtained. Psycho-cognitive measurements such as sleep quality (Pittsburgh Sleep Quality Index) and Go/No-Go test response time were conducted. In addition to physical measurements, serologic parameters including insulin-like growth factor 1 were measured. The factors associated with hand grip strength were analyzed using multiple linear regression analysis after adjusting for age, height, and weight. Results The mean hand grip strength was associated with the Pittsburgh Sleep Quality Index total score (${\beta}=-0.12$, p=0.01), the Go/No-Go test response time (${\beta}=-0.18$, p=0.001), vitamin D (${\beta}=0.12$, p=0.02), and insulin-like growth factor 1 levels (${\beta}=0.1$, p=0.045). In female farmers, hand grip strength was only associated with the Pittsburgh Sleep Quality Index total score (${\beta}=-0.32$, p<0.001). Conclusion The results of this study demonstrate that hand grip strength was associated with sleep quality and attention in Korean farmers.

• 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.

• The Journal of Korean Physical Therapy
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• v.20 no.2
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• pp.49-55
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• 2008

Purpose: The purpose of this study is to find the effect of grip strength of the grasping reflex skill training of 4 case children with spastic cerebral palsy. Smedley hand dynamometer(JAMAR, USA) was used for measuring grip strength. Methods: Smedley hand dynamometer(JAMAR, USA) was used for measuring grip strength. Cases were chosen mild, moderate and severe spastic cerebral palsy with sitting balance and perception. To achieve that purpose, this training program was carried out 5 times a week for 4 weeks with 4 children. The performance of grasping reflex skill training and grip strength was evaluated each other. Results: Both hands were investigated with grasping reflex skill test and grip strength in two week intervals. In the dominant or nondominant hand, the more improvement of grasping reflex skill test is high, the more that of grip strength is high. Conclusion: The result were as follows that. The grasping reflex skill training was effective in grip strength.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.17 no.1
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• pp.24-28
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• 2011

Background: The purpose of this study is to make a grip strength checker to make people measure their grip strength easily, based on standardized grip strength checker chart. Method: In this study, we measured right hand grip strength of 80 women residents of Deajeon (women in their 30s to 60s, 20 in each) 2 times per day for 5days in same conditions from 20th of November 2010 to 24th of November. it was measured by Jamar Hydraculic Hand Dynamometer made lately to compare with the current measuring equipment. No matter how big their hands are, their hands were fixed at second level. Measured as they sit on a chair and let their shoulders gathered and not be rotated, let their arms be 90 degree, wrist and forearm be at the middle for the first time, and took another after they took a rest, and measured the average of the two. Result: There was not a meaningful difference between the current measuring equipment and the equipment made lately (p>.05). Conclusion: It is thought that the equipment made lately can be believed. In addition, we want people to realize their own grip strength easily by this study.

• Journal of agricultural medicine and community health
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• v.48 no.4
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• pp.275-284
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• 2023

Objectives: This study aimed to assess hand grip strength and femoral neck bone mineral density levels among Korean fishery workers and investigate their association. Methods: Hand grip strength and femoral neck bone mineral density were measured in a survey and health examination conducted in 2021 among fishery workers in a southern region of South Korea. Covariates including gender, age, education level, income level, smoking behavior, drinking behavior, family history of hip fractures, use of calcium and vitamin D supplements, hypertension, diabetes, regular exercise, and body mass index were investigated. Multiple regression analysis was employed to assess the association between hand grip strength and femoral neck bone mineral density. Results: Among 147 fishery workers, 8.16% exhibited low hand grip strength levels indicative of possible sarcopenia, and a significant association was found between low hand grip strength and decreased femoral neck bone mineral density (β = -89.14, 95% CI = -160.50, -17.78). Additionally, factors such as women gender, advanced age, family history of hip fractures, and a body mass index below 25 kg/m² were associated with decreased femoral neck bone mineral density. In the subgroup analysis by gender, a correlation between low hand grip strength and decreased femoral neck bone mineral density was observed only in men. Conclusions: Further research is needed to explore various determinants and intervention strategies to prevent musculoskeletal disorders among fishery workers, ultimately enhancing their quality of life and well-being.

• Korean Journal of Adult Nursing
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• v.16 no.1
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• pp.123-134
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• 2004

Purpose: The purpose of this study was to examine the effect of use of a horticultural program on the cognitive function, activities of daily living, and hand grip strength of institutionalized dementia patients. Method: Twenty three study participants completed a five week protocol comprised of one week of baseline and four weeks of treatment. The study design was a one group repeated measurement study. For the first and fifth week of the study period, data was collected with 3 instruments: Korean Version of Hasegawa Dementia Scale (HDS-K), Katz's ADL index, hand grip strength. Data analysis was conducted by SPSS version 10.0. Result: Total HDS-K score(p=.000), Activities of daily living(p=.013) and hand grip strength(p=.001) was significantly improved after treatment compared to the baseline. Conclusion: The horticultural program was effective for improving cognitive function, ADL and hand grip strength of the dementia patients. Repeated studies utilizing a control group are needed, using various durations, plants and processes, to confirm these results and to standardize the horticultural program protocol.

• Journal of the Ergonomics Society of Korea
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• v.16 no.1
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• pp.15-27
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• 1997

The objectives of this study were twofold; (1) to determine an optimal handle size of a signal billy, based on the subjective assessment of grip comfort and (2) to investigate the relationship between hand anthropometry and the optimal handle size. Thirty-seven university male students were asked to rate seven cylindrical handles of different diameters in barehanded and gloved conditions, respectively. Among these handles, 3.5cm diameter of the handle size was found to be the most comfortable, in both bardhanded and gloved conditionsl. However, no statistically significant reduction in grip comfort occurred within handle diameter ranging from 2.5cm to 4.0cm. As the handle diameter was deivated from the range, grip discomfort in creased significantly. A Spearman rank correlation coefficient test revealed that hand anthropometries such as finger lengths, hand circumference, and hand thickness were statistically significant factors on the determination of the optimal handle size. The implications of these findings were discussed. The results of this study can be used as guidelines in designing the hand tools for power grip.