Abstract
OBJECTIVES:
To describe and correlate tongue force and grip strength measures and to verify the association of these measures with water swallowing in different age groups.
METHOD:
Tongue force was evaluated using the Iowa Oral Performance Instrument and grip strength using the Hand Grip in 90 normal individuals, who were divided into three groups: young (18-39 years old), adult (40-59 years old) and elderly (above 60 years old) individuals. The time and number of swallows required for the continuous ingestion of 200 ml of water were also measured.
RESULTS:
A reduction in tongue force and grip strength, as well as an increase in the time required to drink 200 ml of water, were observed with increasing participant age. There was no difference in the number of swallows among the three groups. A correlation was observed between reductions in tongue force and grip strength in the groups of young and elderly individuals.
CONCLUSION:
There were differences in the measures of tongue force in young, adult and elderly individuals. Greater variations within these differences were observed when repeated movements were performed; in addition, a decrease in strength was associated with an increase in age. The decrease in tongue force among the elderly was offset by the increase in time needed to swallow the liquid. There was an association between the measures of tongue force and grip strength in the different age groups. The results of this study can be applied clinically and may act as a basis for guidelines in healthy or vulnerable elderly populations.
Swallowing; Elderly; Sarcopenia
INTRODUCTION
The orofacial motor system is responsible for stomatognathic functions (breathing, mastication, swallowing, suction and speech). The alteration of any structure involved in these functions can adversely affect swallowing and may ultimately lead to dysphagia.
The tongue plays a very important role in swallowing (11. Clark HM, Solomon NP. Age and sex differences in orofacial
strength. Dysphagia. 2012;27(1):2-9,
http://dx.doi.org/10.1007/s00455-011-9328-2.
http://dx.doi.org/10.1007/s00455-011-932...
); it is responsible for compressing food against the hard palate and
moving food toward the oropharynx (22. Corbin-Lewis K, Liss JM, Sciortino KL. Anatomia Clínica e
Fisiologia do Mecanismo de Deglutição. São Paulo, SP: Cengage
Learning, 2009.). The
tongue consists entirely of muscle and plays an essential role because it exerts the
strongest force required to propel food, liquid, secretions and medicine within the
oral cavity and toward the oropharynx (and ultimately the esophagus) during
swallowing (33. Lima RMF, Amaral AKFJ, Aroucha EBL, Vasconcelos TMJ, Silva HJ,
Cunha DA. Adaptações na Mastigação, Deglutição e
Fonoarticulação em Idosos de Instituição de Longa
Permanência. Rev CEFAC, 2009;11(S3):405-22,
http://dx.doi.org/10.1590/S1516-18462009000700017.
http://dx.doi.org/10.1590/S1516-18462009...
). Studies have shown that
lingual pressure increases when the bolus to be propelled has a more solid
consistency (44. Stierwalt JAG, Youmans SR. Tongue measures in individuals with
normal and impaired swallowing. Am J Speech Lang Pathol.
2007;16(2):148-56,
http://dx.doi.org/10.1044/1058-0360(2007/019).
http://dx.doi.org/10.1044/1058-0360(2007...
).
A reduction in muscle strength may indicate fatigue, which is characterized by an
acute reduction in the ability to exert muscle force (55. Gandevia SC. Spinal and supraspinal factors in human muscle
fatigue. Physiol Rev. 2001;81(4):1725-89.). In normal individuals, the age-related loss of muscle mass
associated with a reduction in muscle strength is called sarcopenia (33. Lima RMF, Amaral AKFJ, Aroucha EBL, Vasconcelos TMJ, Silva HJ,
Cunha DA. Adaptações na Mastigação, Deglutição e
Fonoarticulação em Idosos de Instituição de Longa
Permanência. Rev CEFAC, 2009;11(S3):405-22,
http://dx.doi.org/10.1590/S1516-18462009000700017.
http://dx.doi.org/10.1590/S1516-18462009...
). The functional decrease resulting from
sarcopenia appears in striated muscle tissues; this decrease also involves the
muscles that support swallowing, such as those found in the lips, tongue and cheeks
(66. Gingrich LL, Stierwalt JA, Hageman CF, Lapointe LL. Lingual
propulsive pressures across consistencies generated by the anteromedian and
posteromedian tongue by healthy young adults. J Speech Lang Hear Res.
2012;55(3):960-72,
http://dx.doi.org/10.1044/1092-4388(2011/10-0357).
http://dx.doi.org/10.1044/1092-4388(2011...
).
Some studies have examined the effects of aging on tongue force and the consequent
weakness in swallowing. A relationship between tongue lifting force and age has been
reported; i.e., older individuals exert less tongue force during lifting than young
adults (11. Clark HM, Solomon NP. Age and sex differences in orofacial
strength. Dysphagia. 2012;27(1):2-9,
http://dx.doi.org/10.1007/s00455-011-9328-2.
http://dx.doi.org/10.1007/s00455-011-932...
).
Dysphagic individuals have reduced tongue force (77. Robbins J, Levine R, Woo J, Roecker EB, Luschei E. Age effects on
lingual pressure generation as a risk factor for dysphagia.
J Gerontol A Biol Sci Med Sci. 1995;50(5):M257-62,
http://dx.doi.org/10.1093/gerona/50A.5.M257.
http://dx.doi.org/10.1093/gerona/50A.5.M...
); measures of tongue pressure can reflect dysphagia (88. Yoshida M, Kikutani T, Tsuga K, Utanohara Y, Hayashi R, Akagawa
Y. Decreased Tongue Pressure Reflects Symptom of Dysphagia. Dysphagia.
2006;21(1):61-5, http://dx.doi.org/10.1007/s00455-005-9011-6.
http://dx.doi.org/10.1007/s00455-005-901...
).
Reliable tools to objectively measure tongue force and resistance are currently
available. Studies of these tools have confirmed that, although swallowing pressure
remains constant throughout life, the tongue-pressure functional reserve generally
decreases with age (66. Gingrich LL, Stierwalt JA, Hageman CF, Lapointe LL. Lingual
propulsive pressures across consistencies generated by the anteromedian and
posteromedian tongue by healthy young adults. J Speech Lang Hear Res.
2012;55(3):960-72,
http://dx.doi.org/10.1044/1092-4388(2011/10-0357).
http://dx.doi.org/10.1044/1092-4388(2011...
,77. Robbins J, Levine R, Woo J, Roecker EB, Luschei E. Age effects on
lingual pressure generation as a risk factor for dysphagia.
J Gerontol A Biol Sci Med Sci. 1995;50(5):M257-62,
http://dx.doi.org/10.1093/gerona/50A.5.M257.
http://dx.doi.org/10.1093/gerona/50A.5.M...
,99. Utanohara Y, Hayashi R, Yoshikawa M, Yoshida M, Tsuga K, Akagawa
Y. Standard values of maximum tongue pressure taken using newly developed
disposable tongue pressure measurement device. Dysphagia. 2008;23(3):286-90,
http://dx.doi.org/10.1007/s00455-007-9142-z.
http://dx.doi.org/10.1007/s00455-007-914...
). Furthermore,
studies of individuals who suffer from degenerative diseases have demonstrated that
these individuals show a reduction in the tongue force compared to healthy
individuals (1010. Murdoch BE, Spencer TJ, Theodoros DG,Thompson EC. Lip and tongue
function in multiple sclerosis: a physiological analysis. Motor Control.
1998;2(2):148-60.).
Although tongue force can be measured simply, there is a wide variability of
responses among healthy individuals (99. Utanohara Y, Hayashi R, Yoshikawa M, Yoshida M, Tsuga K, Akagawa
Y. Standard values of maximum tongue pressure taken using newly developed
disposable tongue pressure measurement device. Dysphagia. 2008;23(3):286-90,
http://dx.doi.org/10.1007/s00455-007-9142-z.
http://dx.doi.org/10.1007/s00455-007-914...
).
Thus, it is important to accurately measure tongue forces, which permit us to infer
the force required for swallowing (66. Gingrich LL, Stierwalt JA, Hageman CF, Lapointe LL. Lingual
propulsive pressures across consistencies generated by the anteromedian and
posteromedian tongue by healthy young adults. J Speech Lang Hear Res.
2012;55(3):960-72,
http://dx.doi.org/10.1044/1092-4388(2011/10-0357).
http://dx.doi.org/10.1044/1092-4388(2011...
,99. Utanohara Y, Hayashi R, Yoshikawa M, Yoshida M, Tsuga K, Akagawa
Y. Standard values of maximum tongue pressure taken using newly developed
disposable tongue pressure measurement device. Dysphagia. 2008;23(3):286-90,
http://dx.doi.org/10.1007/s00455-007-9142-z.
http://dx.doi.org/10.1007/s00455-007-914...
).
Grip strength is a basic measurement used for research into the functional integrity
of the body (1111. Moura PML. Estudo da força de preensão palmar em
diferentes faixas etárias do desenvolvimento humano. Mestrado. UNB,
2008.). Decreased grip strength has
been consistently shown to be related to a high probability of premature mortality,
the development of disabilities and, cognitive impairment and an increased risk of
complications or prolonged hospital stays (1212. Bohannon RW. Hand-grip dynamometry predicts future outcomes in
aging adults. J Geriatr Phys Ther. 2008;31(1):3-10,
http://dx.doi.org/10.1519/00139143-200831010-00002.
http://dx.doi.org/10.1519/00139143-20083...
).
Medical professionals use grip strength measurements when evaluating elderly patients
and individuals suffering from degenerative diseases (1111. Moura PML. Estudo da força de preensão palmar em
diferentes faixas etárias do desenvolvimento humano. Mestrado. UNB,
2008.,1313. Krishnan V, Jaric S. Hand Function in Multiple Sclerosis: Force
Coordination in Manipulation Tasks. Clin Neurophysiol. 2008; 119(10):2274-81,
http://dx.doi.org/10.1016/j.clinph.2008.06.011.
http://dx.doi.org/10.1016/j.clinph.2008....
). Measurement
using the Hand Grip is a simple, quick, objective, practical and easy-to-interpret
procedure and is a useful screening indicator of vitality in adults and the elderly
(1414. De Vos NJ, Singh NA, Ross DA, Stavrinos TM, Orr R,
Fiatarone-Singh MA. Effect of power-training intensity on the contribution of
force and velocity to peak power in older adults. J Aging Phys Act.
2008;16(4):393-407.).
To the best of our knowledge, no other published studies have used an integrated approach to relate tongue force, grip strength and swallowing.
METHODS
Tongue force was evaluated using the Iowa Oral Performance Instrument (IOPI; IOPI Medical L.L.C.) and grip strength was evaluated using a manual dynamometer (Hand Grip Crown Manual) in 90 normal individuals who were, between 18 and 86 years old. Participants were recruited from the community and did not have any complaints regarding swallowing or a decrease in strength. The participants were divided into three groups: G1 (18 to 39 years old), G2 (40 to 59 years old) and G3 (60 to 90 years old). To obtain tongue force measures, the anteromedian segment of the tongue was studied while performing an isometric task. Individuals were instructed to place the bulb of the IOPI device in their mouths, centrally position it and then push the tongue with the greatest force possible against the palate while swallowing saliva. Force measures were obtained from the device's display (Figure 1). This procedure was performed three consecutive times (T1, T2 and T3), with the highest measurement obtained from each individual considered for the analyses.
For the measurement grip strength, the participant was asked to assume a seated position, with the shoulder adducted and in neutral rotation, with the elbow flexed at 90 degrees; the forearm was in a neutral position and the wrist was between 0 and 30 degrees of extension (Figure 2). While maintaining this position, the participants were asked to squeeze the Hand Grip as strongly as possible with the dominant hand.
The swallowing of 200 ml of water was verified. Participants were asked to drink the entire volume of water in continuous swallows and the swallowing time was measured from the moment the participants touched the glass with their lower lips until the final moment of the final swallow. The examiner measured swallowing by cervical auscultation using a stethoscope (Littmann, Classic II). The measurements were recorded using a digital timer (Kenko, KK 2808).
The different age groups were compared using the Kruskal-Wallis test; the Friedman test was used to compare grip strength and tongue force within each group; the Mann-Whitney test, adjusted with the Bonferroni correction, was used to identify which groups differed from the others (when compared pairwise); the Wilcoxon Signed-Rank Test was used to verify possible differences in the moments of observation for the variables of interest and by group studied, which were considered pairwise; finally, Spearman correlation was used to verify the association between grip strength and tongue force. The significance level accepted was 5%.
Ethics
This study was approved by the Research and Ethics Committee of the Faculty of Medicine of the University of São Paulo, number 70419, on 08/08/2012. All participants signed an informed consent form to participate in the study.
RESULTS
The groups were compared according to the following variables: age, number of swallows and drinking time for 200 ml of water, tongue force and grip strength. Differences were observed in the drinking time for 200 ml of water, tongue force and grip strength. These results are presented in Table 1. Table 2 shows the difference between groups G1 and G3 with respect to drinking time for 200 ml of water, tongue force and dominant hand force; Table 2 also shows differences among tongue forces between groups G2 and G3.
Tongue force measurements were performed three times and were compared among the groups. The older groups showed significant differences in terms of the force variation of the successive tests. The results of this comparison are shown in Table 3.
The T1 observation was disregarded because it represents the moment when individuals had their first contact with the device; the T2 and T3 observations were similar (Table 4).
Wilcoxon Signed-Rank Test, which was used to verify possible differences among the moments of observation, (considered pairwise), for the variables of interest and by group studied.
Finally, the associations between grip strength and tongue force were analyzed among the three groups. Positive and significant correlations were observed; however, the correlation coefficients between the forces of the young and elderly groups were of medium strength, as shown in Table 5.
In short, significant reductions in tongue force and grip strength (as well as significant increases in drinking time for 200 ml of water) were observed with increasing age. The groups exhibited differences with respect to tongue force and grip strength. There was more variability in consecutive tests among individuals from the adult and elderly groups. There was a correlation between tongue force and grip strength in the young and elderly individuals.
DISCUSSION
The objective of this study was to analyze tongue force and grip strength among healthy individuals from different age groups. In addition, this study measured water swallowing times and correlated tongue forces with grip strength among participants of different ages.
It has been proven that age affects swallowing. Although there was no significant
difference in the number of water swallows among the three groups, the drinking time
in the elderly increased substantially, which can be interpreted as an adaptation
and adjustment strategy. This finding is similar to previous studies showing that an
increased swallowing time in individuals with presbyphagia was associated with
functional efficiency (1515. Humbert IA, Robbins JA. Dysphagia in the Elderly. Phys Med
Rehabil Clin N Am. 2008;19(4):853-66,
http://dx.doi.org/10.1016/j.pmr.2008.06.002
http://dx.doi.org/10.1016/j.pmr.2008.06....
).
Although the maintenance of functionality indicates that swallowing impairment in elderly individuals cannot be considered dysphagia, presbyphagia patients have slightly decreased functional reserves. Therefore, it is important to observe the nature of compensation as the drinking time increases. These successful and spontaneous compensatory mechanisms should be disclosed to caregivers of older patients.
The successive measures of tongue force varied significantly among the adult and
elderly groups. Oropharyngeal functional decline is part of the sarcopenia syndrome
and it is no surprise that this syndrome occurs as an individual ages, as has been
reported in other studies (77. Robbins J, Levine R, Woo J, Roecker EB, Luschei E. Age effects on
lingual pressure generation as a risk factor for dysphagia.
J Gerontol A Biol Sci Med Sci. 1995;50(5):M257-62,
http://dx.doi.org/10.1093/gerona/50A.5.M257.
http://dx.doi.org/10.1093/gerona/50A.5.M...
). However, the
decrease in force with age occurs during pre-senescence, which is unusual. In our
study, there was a significant reduction in the G2 and G3 groups. These data confirm
the idea that the functional reserve in elderly individuals is lower than in younger
individuals (1616. Ney D, Weiss J, Kind AJH, Robbins J. Senescent swallowing:
Impact, strategies and interventions. Nutr Clin Pract. 2009;24(3):395-413,
http://dx.doi.org/10.1177/0884533609332005.
http://dx.doi.org/10.1177/08845336093320...
).
One important aspect that should be considered is the risk for dysphagia, which can lead to pulmonary and nutritional complications in the elderly and contributes to a decrease in the quality of life in this population.
It is possible to infer swallowing force by measuring the swallowing of saliva (77. Robbins J, Levine R, Woo J, Roecker EB, Luschei E. Age effects on
lingual pressure generation as a risk factor for dysphagia.
J Gerontol A Biol Sci Med Sci. 1995;50(5):M257-62,
http://dx.doi.org/10.1093/gerona/50A.5.M257.
http://dx.doi.org/10.1093/gerona/50A.5.M...
). Therefore, we understand that the detection
of a decrease in swallowing force among elderly individuals can indicate the need
for beginning preventive measures, such as training to increase functional reserve,
once the elderly become vulnerable to presbyphagia and other diseases that accompany
impaired swallowing.
It would be interesting to incorporate the measurement of tongue force in clinical evaluations to identify vulnerable individuals. Such investigations may lead to other untapped avenues relating to our work.
The loss of muscle strength associated with sarcopenia is generally measured by grip strength, which constitutes an individual's vitality index. In addition to being associated with fragility, a decrease in strength is also an indicator of cognitive impairment (1717. Neri AL, Yassuda MS, Araújo LF, Eulálio M do C, Cabral BE, et al. Caderno de Saúde Pública. 2013;29(4):778-92.). In Brazil, this measure determines whether one can renew a driver's license (1818. www.denatran.gov.br/download/Resolucoes/resolucao080_98.doc. Researched in 2013 Nov.). Thus, the measurement of grip strength is used often and is available for a wide range of elderly individuals.
As observed in Buehring's study (1919. Buehring B, Hind J, Fidler E, Krueger D, Binkley N, Robbins J.
Tongue strength is associated with jumping mechanography performance and
handgrip strength but not with classic functional tests in older adults.
J Am Geriatr Soc. 2013;61(3):418-22,
http://dx.doi.org/10.1111/jgs.12124.
http://dx.doi.org/10.1111/jgs.12124...
), our
study demonstrated that there is a relationship between tongue force and grip
strength measures in both the youngest (G1) and the oldest age groups (G3). This
relationship was not observed in G2, perhaps due to the number of individuals in the
study. There is value in measuring the association between grip strength and tongue
force in elderly individuals, even those without sarcopenia (1919. Buehring B, Hind J, Fidler E, Krueger D, Binkley N, Robbins J.
Tongue strength is associated with jumping mechanography performance and
handgrip strength but not with classic functional tests in older adults.
J Am Geriatr Soc. 2013;61(3):418-22,
http://dx.doi.org/10.1111/jgs.12124.
http://dx.doi.org/10.1111/jgs.12124...
), due to the vulnerability of this age group.
The finding of an association between grip strength and tongue force shows the necessity for consideration of including both measurements when evaluating the elderly; furthermore, it is important to consider the role of preventive actions for swallowing dysfunction within this age group.
The objective of our study was to evaluate tongue force, grip strength and swallowing function (during continuous swallows of water) in an integrated fashion. This integrated approach made it possible to incorporate signals from different evaluations to detect potential deficits in swallowing.
There were differences in the tongue force measures among the young, adult and elderly individuals. These differences appeared to have increased variability when consecutive movements were performed; in addition, there was an association between decreased strength and increased age.
The decrease in tongue force in the elderly age group was offset by the increased time to swallow liquids.
There was a relationship between tongue force and grip strength in the different age groups.
The results of this study can be applied clinically and may act as a basis for guidelines in both healthy and vulnerable elderly individuals.
We thank all participants in this study.
REFERENCES
-
1Clark HM, Solomon NP. Age and sex differences in orofacial strength. Dysphagia. 2012;27(1):2-9, http://dx.doi.org/10.1007/s00455-011-9328-2.
» http://dx.doi.org/10.1007/s00455-011-9328-2 -
2Corbin-Lewis K, Liss JM, Sciortino KL. Anatomia Clínica e Fisiologia do Mecanismo de Deglutição. São Paulo, SP: Cengage Learning, 2009.
-
3Lima RMF, Amaral AKFJ, Aroucha EBL, Vasconcelos TMJ, Silva HJ, Cunha DA. Adaptações na Mastigação, Deglutição e Fonoarticulação em Idosos de Instituição de Longa Permanência. Rev CEFAC, 2009;11(S3):405-22, http://dx.doi.org/10.1590/S1516-18462009000700017.
» http://dx.doi.org/10.1590/S1516-18462009000700017 -
4Stierwalt JAG, Youmans SR. Tongue measures in individuals with normal and impaired swallowing. Am J Speech Lang Pathol. 2007;16(2):148-56, http://dx.doi.org/10.1044/1058-0360(2007/019).
» http://dx.doi.org/10.1044/1058-0360(2007/019) -
5Gandevia SC. Spinal and supraspinal factors in human muscle fatigue. Physiol Rev. 2001;81(4):1725-89.
-
6Gingrich LL, Stierwalt JA, Hageman CF, Lapointe LL. Lingual propulsive pressures across consistencies generated by the anteromedian and posteromedian tongue by healthy young adults. J Speech Lang Hear Res. 2012;55(3):960-72, http://dx.doi.org/10.1044/1092-4388(2011/10-0357).
» http://dx.doi.org/10.1044/1092-4388(2011/10-0357) -
7Robbins J, Levine R, Woo J, Roecker EB, Luschei E. Age effects on lingual pressure generation as a risk factor for dysphagia. J Gerontol A Biol Sci Med Sci. 1995;50(5):M257-62, http://dx.doi.org/10.1093/gerona/50A.5.M257.
» http://dx.doi.org/10.1093/gerona/50A.5.M257 -
8Yoshida M, Kikutani T, Tsuga K, Utanohara Y, Hayashi R, Akagawa Y. Decreased Tongue Pressure Reflects Symptom of Dysphagia. Dysphagia. 2006;21(1):61-5, http://dx.doi.org/10.1007/s00455-005-9011-6.
» http://dx.doi.org/10.1007/s00455-005-9011-6 -
9Utanohara Y, Hayashi R, Yoshikawa M, Yoshida M, Tsuga K, Akagawa Y. Standard values of maximum tongue pressure taken using newly developed disposable tongue pressure measurement device. Dysphagia. 2008;23(3):286-90, http://dx.doi.org/10.1007/s00455-007-9142-z.
» http://dx.doi.org/10.1007/s00455-007-9142-z -
10Murdoch BE, Spencer TJ, Theodoros DG,Thompson EC. Lip and tongue function in multiple sclerosis: a physiological analysis. Motor Control. 1998;2(2):148-60.
-
11Moura PML. Estudo da força de preensão palmar em diferentes faixas etárias do desenvolvimento humano. Mestrado. UNB, 2008.
-
12Bohannon RW. Hand-grip dynamometry predicts future outcomes in aging adults. J Geriatr Phys Ther. 2008;31(1):3-10, http://dx.doi.org/10.1519/00139143-200831010-00002.
» http://dx.doi.org/10.1519/00139143-200831010-00002 -
13Krishnan V, Jaric S. Hand Function in Multiple Sclerosis: Force Coordination in Manipulation Tasks. Clin Neurophysiol. 2008; 119(10):2274-81, http://dx.doi.org/10.1016/j.clinph.2008.06.011.
» http://dx.doi.org/10.1016/j.clinph.2008.06.011 -
14De Vos NJ, Singh NA, Ross DA, Stavrinos TM, Orr R, Fiatarone-Singh MA. Effect of power-training intensity on the contribution of force and velocity to peak power in older adults. J Aging Phys Act. 2008;16(4):393-407.
-
15Humbert IA, Robbins JA. Dysphagia in the Elderly. Phys Med Rehabil Clin N Am. 2008;19(4):853-66, http://dx.doi.org/10.1016/j.pmr.2008.06.002
» http://dx.doi.org/10.1016/j.pmr.2008.06.002 -
16Ney D, Weiss J, Kind AJH, Robbins J. Senescent swallowing: Impact, strategies and interventions. Nutr Clin Pract. 2009;24(3):395-413, http://dx.doi.org/10.1177/0884533609332005.
» http://dx.doi.org/10.1177/0884533609332005 -
17Neri AL, Yassuda MS, Araújo LF, Eulálio M do C, Cabral BE, et al. Caderno de Saúde Pública. 2013;29(4):778-92.
-
18www.denatran.gov.br/download/Resolucoes/resolucao080_98.doc. Researched in 2013 Nov.
-
19Buehring B, Hind J, Fidler E, Krueger D, Binkley N, Robbins J. Tongue strength is associated with jumping mechanography performance and handgrip strength but not with classic functional tests in older adults. J Am Geriatr Soc. 2013;61(3):418-22, http://dx.doi.org/10.1111/jgs.12124.
» http://dx.doi.org/10.1111/jgs.12124
-
No potential conflict of interest was reported.
Publication Dates
-
Publication in this collection
Jan 2015
History
-
Received
14 Oct 2014 -
Reviewed
12 Nov 2014 -
Accepted
12 Nov 2014