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Nutrición Hospitalaria

versión On-line ISSN 1699-5198versión impresa ISSN 0212-1611

Nutr. Hosp. vol.35 no.1 Madrid ene./feb. 2018

http://dx.doi.org/10.20960/nh.1052 

Trabajos Originales

Normative reference values for hand grip dynamometry in Spain. Association with lean mass

Valores de normalidad de dinamometría de mano en España. Relación con la masa magra

Francisco-José Sánchez-Torralvo1  , Nuria Porras1  , José Abuín-Fernández1  , Francisca García-Torres1  , María-José Tapia1  , Fuensanta Lima1  , Federico Soriguer1  , Montserrat Gonzalo1  , Gemma Rojo-Martínez1  2  , Gabriel Olveira1  2 

1Unidad de Gestión Clínica de Endocrinología y Nutrición. IBIMA. Hospital Regional Universitario de Málaga-Universidad de Málaga. Málaga, Spain

2CIBERDEM-CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CB07/08/0019). Instituto de Salud Carlos III. Madrid, Spain

Abstract

Background and objectives:

The objective of this study was to establish reference values for hand grip strength, compare the results obtained with Collin and Jamar type dynamometers and determine their association with anthropometric and lean mass measurements.

Material and methods:

This cross-sectional population-based study was undertaken in Pizarra (Málaga, Spain). The grip strength of the dominant hand was measured using Collin and Jamar dynamometers. Skinfolds (triceps, abdominal, biceps of dominant arm and subscapular) were measured, and body composition was estimated. Eight hundred seventeen adults randomly selected from the census were recruited. Dynamometry reference values are presented for the dominant hand, by gender and age groups.

Results:

No determinations could be made with the Collin dynamometer in 69 women due to the difficulty in grasping the dynamometer. We found significant positive correlations between the measurements with Jamar and Collin dynamometers (r = 0.782; p < 0.001) and between grip strength and lean mass index (LMI), determined by both dynamometers (r = 0.538, p < 0.001 and r = 0.462, p < 0.001, respectively). Malnourished patients according to LMI had significantly lower grip strength than normally nourished patients (p < 0.001 for Jamar; p < 0.02 for Collin).

Conclusions:

Dynamometry reference values in the Spanish population are presented. We recommend the use of the Jamar type dynamometer versus the Collin type dynamometer. Hand grip dynamometry is associated with lean mass, which confirms its usefulness in nutritional assessment.

Key words: Hand strength; Reference values; Hand grip; Dynamometry; Nutritional status

Resumen

Antecedentes y objetivos:

no existen valores de normalidad en España con el dinamómetro Jamar. El objetivo fue determinar valores de normalidad de fuerza muscular, comparar los resultados obtenidos con los dinamómetros tipo Collin y tipo Jamar entre sí, y determinar su asociación con medidas antropométricas y de masa magra.

Material y métodos:

estudio transversal de base poblacional en Pizarra (Málaga). Se determinó la fuerza de prensión de la mano dominante mediante dinamómetros Collin y Jamar. Se midieron los pliegues cutáneos (tricipital, abdominal, bicipital del brazo dominante y subescapular) y se estimó la composición corporal. Se reclutaron 817 adultos seleccionados aleatoriamente del censo. Se presentan valores de referencia de dinamometría para la mano dominante, por género y grupos de edad.

Resultados:

no se pudieron realizar determinaciones con el dinamómetro Collin en 69 mujeres debido a la dificultad para agarrar el dinamómetro. Encontramos correlaciones positivas significativas entre las medidas de los dinamómetros Jamar y Collin (r = 0,782; p < 0,001) y entre la fuerza muscular determinada mediante ambos dinamómetros y el índice de masa magra (IMM) (r = 0,538, p < 0,001 y r = 0,462, p < 0,001, respectivamente). Los pacientes desnutridos según IMM presentaron una fuerza muscular significativamente menor a la de los pacientes normonutridos (p < 0,001 para Jamar y p < 0,02 para Collin).

Conclusiones:

se presentan valores de referencia de dinamometría en población española. Recomendamos el uso del dinamómetro tipo Jamar frente al dinamómetro tipo Collin. La dinamometría de mano se asocia con la masa magra, lo que avala su utilidad en la valoración nutricional.

Palabras clave: Fuerza muscular; Valores de normalidad. Prensión de la mano; Dinamometría. Estado nutricional

INTRODUCTION

There is a great variety of techniques to evaluate the nutritional status of a patient, although there is no single parameter available. Malnutrition implies a decrease in muscle mass, which is reflected in poorer performance on functional tests and alterations in body composition 1) (2) (3. This decrease in muscle strength appears before changes in anthropometric measurements and laboratory parameters are observed. Accordingly, the measurement of muscle strength may be a useful tool in screening and assessing malnutrition 4. The American Society for Parenteral and Enteral Nutrition has included the assessment of grip strength by dynamometer as one of the six criteria to define malnutrition 5, encouraging the use of cut-off points in each population by age and gender 6.

There are numerous clinical studies in hospitalized individuals or outpatients (surgical, elderly, oncological, etc.) that demonstrate that decreased grip strength, measured by hand dynamometry, is associated with increased stays, mortality and complications 3) (7) (8. Similarly, in epidemiological studies performed in different age groups, decreased grip strength is also associated with higher mortality and impaired functionality 3. Some body composition measures, like lean mass, seem to have a close relationship with hand strength as well as with physical function 9.

The hand dynamometer evaluates the isometric force of the hand and the forearm providing a quick, easy to use, and inexpensive method to assess the grip strength and, thus, the nutritional status of patients 10. Currently, the Jamar dynamometer is the most commonly used in clinical practice 4) (11) (12) (13. Over the last few years, dynamometry reference values have been published in different countries, usually for the Jamar-type dynamometer 4) (11) (14) (15, including a meta-analysis 16.

In Spain, the normative data are from another type of dynamometer 17) (18) (19 with no studies using the Jamar dynamometer. Likewise, there are no data comparing the results of the two different types of dynamometers, so it remains unknown if the measurements of both dynamometers are comparable in clinical practice. There are only a few studies relating dynamometry results to body composition 15) (20. The objective of this study was to contribute reference values in a sample of subjects belonging to the general population in Spain using the Jamar dynamometer, to compare them with the Collin dynamometer, and to assess the relationship between dynamometry and anthropometric parameters, especially lean mass.

MATERIAL AND METHODS

Our sample comprised a total of 817 healthy adults recruited from the population-based Pizarra study (Malaga) 21. These individuals, aged between 18 and 65 years, were randomly selected from the municipal census. Individuals who were institutionalized, pregnant, or who had severe physical or psychiatric conditions were excluded as were morbidly obese subjects (body mass index [BMI] > 40 kg/m2). All subjects gave their written consent, and the study was approved by the Ethics and Clinical Research Committee of the Regional University Hospital of Malaga.

Anthropometric measurements included weight, obtained with a scale adjusted to 0.1 kg (SECA 665, Seca, Germany), and height, using a stadiometer adjusted to 0.01 m (Holtain Ltd., Croswell, UK), to calculate BMI. Skinfold thicknesses (subscapular, triceps, biceps, abdominal) were measured at standard sites 22 by a single investigator using a plicometer (Holtain Ltd., Croswell, UK) with the precision of 0.2 mm. Three measurements were taken and the mean was calculated. Arm circumference was measured using a flexible measuring tape to the nearest 0.1 cm at the midpoint of the arm. Lean mass and fat mass percentages were estimated using the Durnin 23 and Siri 24 equations. Hand dynamometry was performed using a Collin dynamometer (Medizintechnik AS, Germany) and a Jamar dynamometer (Asimow Engineering Co., Los Angeles, CA).

In the case of the Jamar dynamometer, the subjects were instructed to adjust the device so that the grip would be comfortable for their hand to obtain the best performance 25, although most chose to use the second position (3.8 cm). The subjects were instructed to squeeze the dynamometer with the maximum force they could apply after receiving a verbal command 26.

The measurements were taken with the patients sitting in a straight back chair with both feet on the ground, shoulders close to the body in a neutral position, and the elbow flexed at 90° without rotation 27.

Three measurements were obtained in the dominant hand with a rest period of at least one minute between trial 28. There was a minimum ten minute break between Collin and Jamar measurements, in that order.

The mean was calculated and the highest value was used to represent hand grip strength.

STATISTICAL ANALYSIS

Data analysis was performed using SPSS Statistics software v22. Descriptive data are shown as means and standard deviations. The Kolmogorov-Smirnov test was used to establish whether the variables followed a normal distribution.

In the hypothesis testing for continuous variables between groups, the Student's t test was used in the variables that followed a normal distribution and a non-parametric test (Mann-Whitney) was used for variables that were not normally distributed. We rejected the null hypothesis with an alpha of 0.05 for two tails. The degree of association between hand dynamometry, BMI and body composition measurements was analyzed using the Pearson's correlation coefficient.

RESULTS

A total of 817 adults, 364 men and 453 women, were studied (Table I).

The measurements were valid for the Jamar dynamometer in all subjects studied, but only in 748 cases for the Collin dynamometer (364 men and 384 women), due to the difficulty for grasping the dynamometer. A total of 69 women could not apply the necessary force. Their mean age was 54.6 (± 9.2) years, significantly higher (p < 0.001) than in the group of women who were able to perform the test (47.8 ± 9.2 years). Table II and Table III show the grip strength values for the two dynamometers used, grouped by gender and distributed by age, together with their corresponding percentiles.

Table I General and anthropometric characteristics of the study population 

n: number. BMI: body mass index.

Table II Strength of the dominant hand by gender and age, measured with a Collin dynamometer 

SD: standard deviation.

Table III Strength of the dominant hand by gender and age, measured with a Jamar dynamometer 

SD: standard deviation.

A high correlation was found between the data obtained with the Jamar and Collin dynamometers (r = 0.782; p < 0.001) (Fig. 1). Mean strength was higher in men than in women with both instruments and in all age groups (p < 0.001). There was a tendency towards a negative correlation between age and grip strength with the Jamar dynamometer (r = -0.67; p = 0.58), which was significant with the Collin dynamometer (r = -0.143; p < 0.001). This significant correlation was observed with the Collin dynamometer in the subjects between the ages of 45 and 60 (r = -0.1; p = 0.04), and those above 60 years (r = -0.22; p = 0.02), which was not the case in those under age 45 (r = 0.02; p = 0.74). With the Jamar type dynamometer, this correlation was significant in the group of subjects under age 45 (r = 0.12; p = 0.04), in those between the ages of 45 and 60 (r = -0.12; p = 0.023) and in subjects over 60 years of age (r = -0.2; p = 0.02).

Figure 1 Relationship between hand grip strength measured by Collin dynamometer and Jamar dynamometer. 

A positive correlation was found between grip strength using the Jamar dynamometer and BMI (r = 0.086; p = 0.014). This relationship increased when subjects were classified as normal weight (r = 0.268; p < 0.001) or overweight (r = 0.146; p = 0.006). No association was found between BMI and grip strength in obese patients.

The values obtained using the Jamar dynamometer showed a positive correlation with weight (r = 0.514; p < 0.001), height (r = 0.714; p < 0.001), and arm circumference (r = 0.249; p < 0.001), and a negative correlation with fat mass in kg: (r = -0.597; p < 0.001), triceps skinfold (r = -0.497; p < 0.001), biceps skinfold (r = -0.404; p < 0.001) and subscapular skinfold (r = -0.209; p < 0.001). There was also a significantly positive correlation between muscle strength and lean mass in kg (r = 0.774; p < 0.001) and lean mass index (LMI) (r = 0.538; p < 0.001) (Fig. 2 and Fig. 3).

Figure 2 Relationship between hand grip strength (Jamar) and lean mass. 

Mean values obtained using the Collin dynamometer showed a positive correlation with weight (r = 0.434; p < 0.001), height (r = 0.663; p < 0.001) and arm circumference (r = 0.206; p < 0.001), and a negative correlation with fat mass (kg): (r = -0.569; p < 0.001), triceps skinfold (r = -0.518; p < 0.001), biceps skinfold (r = -0.404; p < 0.001) and subscapular skinfold (r = -0.214; p < 0.001). There was also a significantly positive correlation between grip strength and lean mass (kg) (r = 0.683; p < 0.001) and LMI (r = 0.462; p < 0.001).

Figure 3 Relationship between hand grip strength (Jamar) and lean mass index. 

Stratifying our population by European Society of Clinical Nutrition and Metabolism criteria (LMI of 17 kg/m2 for men and 15 kg/m2 for women [29]), patients considered as malnourished due to low lean mass had significantly lower mean grip strength than normally nourished patients, both with the Jamar dynamometer and with the Collin dynamometer (Table IV).

Table IV Hand grip strength for both dynamometers according to lean mass index as malnutrition criteria 

LMI: lean mass index. Low LMI interpreted as LMI < 17 kg/m2 in men and LMI < 15 kg/m2 in women.

DISCUSSION

In this study, we present normative reference values for the Spanish population using a Jamar hand dynamometer, a dynamometer for which there were no previous references in Spain, providing cut-off points to define malnutrition. Our results are similar to those of other studies that have published reference values for the Jamar-type dynamometer in Caucasian populations 14) (20) (30.

In the total sample, the cut-off points to define malnutrition (5th percentile) were 29 kg in men and 14 kg in women for the Jamar dynamometer, although this varied depending on age (Table III). These values are similar to those of other studies 15) (20 and may be related to poorer functionality, as some authors suggest 31) (32.

Similar to other studies 4) (20) (27, our values were significantly higher in men than in women for all age groups and negative correlations with age were observed, finding a decrease in grip strength (4). This has been attributed to age-related sarcopenia, since the weight loss that occurs with aging is primarily due to the loss of lean mass, thus leading to loss of grip strength 17. In our sample, no significant differences between the groups of individuals under 45 years and between 45 and 60 years were found, possibly because age-related sarcopenia appears especially in subjects aged 60 and older 4.

As in other studies, a positive association was found between grip strength and anthropometric measures such as weight, BMI, arm circumference, and height 11) (33, although the association is weak 14.

A close correlation between dynamometry values and lean mass was also observed. Patients who met criteria for malnutrition according to LMI 29 presented lower hand grip strength. Since malnutrition due to low lean mass is primarily associated with increased morbidity and mortality related to malnutrition 29, dynamometry becomes a measure that provides a clear added value to nutritional assessment.

In subjects with acute or chronic disease, numerous factors may influence decreased muscle strength, including immobilization, decreased intake, inflammation, oxidative stress, electrolyte disturbances, use of drugs (corticosteroids, muscle relaxants, etc.). In this respect, grip strength is an excellent marker of functionality as, unlike weight, it can discriminate between malnourished individuals and those who are simply underweight and share the same BMI 10.

Furthermore, nutritional intervention studies have demonstrated significant improvement in muscle strength in the short and medium term, which also supports hand grip usefulness in patient follow-up 3) (34.

We found good correlations between grip strength measured with both dynamometers. Although the Collin dynamometer is significantly more economical, we believe its use may be less suitable than that of the Jamar dynamometer because some people (especially older women) have some difficulty in correctly grasping the device and applying force, so the measurement may not be valid. This may be of special relevance in the hospital setting, where the mean inpatients age is high.

STRENGTHS AND WEAKNESSES

Our work was carried out in the context of a population-based epidemiological study with an adequate sample size. Moreover, we measured anthropometric parameters enabling us to relate muscle strength to body composition, especially to lean mass.

Nonetheless, this was a cross-sectional study in which other parameters of functionality were not evaluated, nor was the long-term effect on morbidity and mortality verified. Measurements were only taken in the dominant hand, although some studies suggest that dominance does not affect grip strength 15) (33) (35. Finally, there was a large percentage of subjects with obesity, which could have partially conditioned the results.

CONCLUSIONS

We present reference values for hand dynamometry using a Jamar hand dynamometer for a Spanish population, providing cut-off points to define malnutrition. We recommend using the Jamar dynamometer as opposed to the Collin dynamometer in clinical practice. Hand dynamometry is associated with lean mass, which supports its usefulness in nutritional assessment.

ACKNOWLEDGMENTS

We would like to thank the town of Pizarra and all those who participated in the study.

REFERENCES

1. Hornby ST, Nunes QM, Hillman TE, Stanga Z, Neal KR, Rowlands BJ, et al. Relationships between structural and functional measures of nutritional status in a normally nourished population. Clin Nutr 2005;24(3):421-6. [ Links ]

2. Norman K, Schütz T, Kemps M, Lübke HJ, Lochs H, Pirlich M. The Subjective Global Assessment reliably identifies malnutrition-related muscle dysfunction. Clin Nutr 2005;24(1):143-50. [ Links ]

3. Norman K, Stobäus N, González MC, Schulzke JD, Pirlich M, Symreng T, et al. Hand grip strength: Outcome predictor and marker of nutritional status. Clin Nutr 2011;30(2):135-42. [ Links ]

4. Budziareck MB, Pureza Duarte RR, Barbosa-Silva MCG. Reference values and determinants for handgrip strength in healthy subjects. Clin Nutr 2008;27(3):357-62. [ Links ]

5. White JV, Guenter P, Jensen G, Malone A, Schofield M, Academy of Nutrition and Dietetics Malnutrition Work Group, et al. Consensus statement of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition: Characteristics recommended for the identification and documentation of adult malnutrition (undernutrition). J Acad Nutr Diet 2012;112(5):730-8. [ Links ]

6. Malone A, Hamilton C. The Academy of Nutrition and Dietetics/The American Society for Parenteral and Enteral Nutrition Consensus Malnutrition Characteristics: Application in Practice. Nutr Clin Pract 2013;28(6):639-50. [ Links ]

7. Gale CR, Martyn CN, Cooper C, Sayer AA. Grip strength, body composition, and mortality. Int J Epidemiol 2007;36(1):228-35. [ Links ]

8. Rantanen T, Volpato S, Ferrucci L, Heikkinen E, Fried LP, Guralnik JM. Handgrip strength and cause-specific and total mortality in older disabled women: Exploring the mechanism. J Am Geriatr Soc 2003;51(5):636-41. [ Links ]

9. Araujo AB, Chiu GR, Kupelian V, Hall SA, Williams RE, Clark R V, et al. Lean mass, muscle strength, and physical function in a diverse population of men: A population-based cross-sectional study. BMC Public Health 2010;10(1):508. [ Links ]

10. Vaz M, Thangam S, Prabhu A, Shetty PS. Maximal voluntary contraction as a functional indicator of adult chronic undernutrition. Br J Nutr 1996;76:9-15. [ Links ]

11. Mitsionis G, Pakos EE, Stafilas KS, Paschos N, Papakostas T, Beris AE. Normative data on hand grip strength in a Greek adult population. Int Orthop 2009;33(3):713-7. [ Links ]

12. Schlüssel MM, Dos Anjos LA, De Vasconcellos MTL, Kac G. Reference values of handgrip dynamometry of healthy adults: A population-based study. Clin Nutr 2008;27(4):601-7. [ Links ]

13. Werle S, Goldhahn J, Drerup S, Simmen BR, Sprott H, Herren DB. Age- and gender-specific normative data of grip and pinch strength in a healthy adult Swiss population. J Hand Surg Eur Vol 2009;34(1):76-84. [ Links ]

14. Massy-Westropp NM, Gill TK, Taylor AW, Bohannon RW, Hill CL. Hand grip strength: Age and gender stratified normative data in a population-based study. BMC Res Notes 2011;4:127. [ Links ]

15. Peters MJH, Van Nes SI, Vanhoutte EK, Bakkers M, Van Doorn PA, Merkies ISJ, et al. Revised normative values for grip strength with the Jamar dynamometer. J Peripher Nerv Syst 2011;16(1):47-50. [ Links ]

16. Bohannon RW, Peolsson A, Massy-Westropp N, Desrosiers J, Bear-Lehman J, Rothstein JM, et al. Reference values for adult grip strength measured with a Jamar dynamometer: A descriptive meta-analysis. Physiotherapy 2006;92(1):11-5. [ Links ]

17. Lázaro MLM, Penacho Lázaro MA, Losantos FB, Plaza Bayo A. Nuevas tablas de fuerza de la mano para población adulta de Teruel. Nutr Hosp 2008;23(1):35-40. [ Links ]

18. Luna-Heredia E, Martín-Peña G, Ruiz-Galiana J. Handgrip dynamometry in healthy adults. Clin Nutr 2005;24(2):250-8. [ Links ]

19. Marrodán Serrano MD, Romero Collazos JF, Moreno Romero S, Mesa Santurino MS, Cabañas Armesilla MD, Pacheco Del Cerro JL, et al. Handgrip strength in children and teenagers aged from 6 to 18 years: Reference values and relationship with size and body composition. An Pediatr 2009;70(4):340-8. [ Links ]

20. Dodds RM, Syddall HE, Cooper R, Benzeval M, Deary IJ, Dennison EM, et al. Grip strength across the life course: Normative data from twelve British studies. PLoS One 2014;9(12):e113637. [ Links ]

21. Soriguer F, Gutiérrez-Repiso C, Rubio-Martín E, García-Fuentes E, Almaraz MC, Colomo N, et al. Metabolically healthy but obese, a matter of time? Findings from the prospective Pizarra study. J Clin Endocrinol Metab 2013;98(6):2318-25. [ Links ]

22. Olveira G. Manual de nutrición clínica y dietética. 3rd ed. Olveira G, ed. Madrid: Díaz de Santos; 2007. p. 188-9. [ Links ]

23. Durnin JV, Womersley J. Body fat assessed from total body density and its estimation from skinfold thickness: Measurements on 481 men and women aged from 16 to 72 years. Br J Nutr 1974;32(1):77-97. [ Links ]

24. Siri WE. Body composition from fluid spaces and density: Analysis of methods. 1961. Nutrition 1993;9(5):480-92. [ Links ]

25. Boadella JM, Kuijer PP, Sluiter JK, Frings-Dresen MH. Effect of self-selected handgrip position on maximal handgrip strength. Arch Phys Med Rehabil 2005;86(2):328-31. [ Links ]

26. Johansson CA, Kent BE, Shepard KF. Relationship between verbal command volume and magnitude of muscle contraction. Phys Ther 1983;63(8):1260-5. [ Links ]

27. Mathiowetz V, Kashman N, Volland G, Weber K, Dowe M, Rogers S. Grip and pinch strength: Normative data for adults. Arch Phys Med Rehabil 1985;66(2):69-74. [ Links ]

28. Watanabe T, Owashi K, Kanauchi Y, Mura N, Takahara M, Ogino T. The short-term reliability of grip strength measurement and the effects of posture and grip span. J Hand Surg Am 2005;30(3):603-9. [ Links ]

29. Cederholm T, Bosaeus I, Barazzoni R, Bauer J, Van Gossum A, Klek S, et al. Diagnostic criteria for malnutrition - An ESPEN Consensus Statement. Clin Nutr 2015;34(3):335-40. [ Links ]

30. Mendes J, Alves P, Amaral TF. Comparison of nutritional status assessment parameters in predicting length of hospital stay in cancer patients. Clin Nutr 2014;33(3):466-70. [ Links ]

31. Lauretani F, Russo CR, Bandinelli S, Bartali B, Cavazzini C, Di Iorio A, et al. Age-associated changes in skeletal muscles and their effect on mobility: An operational diagnosis of sarcopenia. J Appl Physiol 2003;95(5):1851-60. [ Links ]

32. Sallinen J, Stenholm S, Rantanen T, Heliövaara M, Sainio P, Koskinen S. Hand-grip strength cut points to screen older persons at risk for mobility limitation. J Am Geriatr Soc 2010;58(9):1721-6. [ Links ]

33. Günther CM, Bürger A, Rickert M, Crispin A, Schulz CU. Grip strength in healthy Caucasian adults: Reference values. J Hand Surg Am 2008;33(4):558-65. [ Links ]

34. Olveira G, Olveira C, Doña E, Palenque FJ, Porras N, Dorado A, et al. Oral supplement enriched in HMB combined with pulmonary rehabilitation improves body composition and health related quality of life in patients with bronchiectasis (Prospective, Randomised Study). Clin Nutr 2016;35(5):1015-22. [ Links ]

35. Bohannon RW. Grip strength: A summary of studies comparing dominant and nondominant limb measurements. Percept Mot Skills 2003;96(3 Pt 1):728-30. [ Links ]

Received: February 19, 2017; Accepted: October 09, 2017

Correspondence: Gabriel Olveira. Unidad de Gestión Clínica de Endocrinología y Nutrición. Hospital Civil (Complejo del Hospital Regional Universitario de Málaga). Plaza del Hospital Civil, s/n. Pabellón 1, sótano. 29009 Málaga e-mail: gabrielm.olveira.sspa@juntadeandalucia.es

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