Comparative effect of different treatment approaches on lumbar hyperlordosis, respiratory muscle strength, and balance in diplegic children: A randomized controlled clinical trial
Abstract
The aim of this study was to compare the effect of different treatment approaches (pressure biofeedback training of the abdominal drawing-in maneuver with and without prone hip extension, whole-body vibration, and core stability exercises) on lumbar hyperlordosis, respiratory muscle strength, and balance in children with diplegic cerebral palsy. Forty-five children, ranged in age from 8 to 12 years, were randomly allocated into three groups (A, B, C). All children underwent a specialized exercise program for one hour, three days/ week for three successive months. In addition, group A received pressure biofeedback training, group B underwent the whole-body vibration, and group C underwent the core stability exercises. The lumbar lordotic angle, active lumbar and hip range of motion, respiratory muscle strength, and balance were measured before and after three months of treatment. We found a significant decrease in lumbar lordotic angle along with a significant increase in active lumbar and hip range of motion of group A and group C post-treatment (p < 0.001) in favor of group A, while non-significant change was found in group B (p > 0.05). A significant improvement was recorded in the three groups' respiratory muscle strength and stability indices in favor of group B (p < 0.001). Pressure biofeedback training and core stability exercises are the best adjunctive to traditional physical therapy to improve lumbar hyperlordosis, respiratory muscle strength, and balance together in children with diplegic cerebral palsy. Moreover, whole-body vibration is the best adjunctive to improve respiratory muscle strength and balance.
Downloads
References
Abbasi, E., Kahrizi, S., Razi, M., & Faghihzadeh, S. (2017). The effect of whole-body vibration training on the lower extremity muscles' electromyographic activities in patients with knee osteoarthritis. Medical journal of the Islamic Republic of Iran, 31, 107. https://doi.org/10.14196/mjiri.31.107
Ahmadizadeh, Z., Khalili, M. A., Ghalam, M. S., & Mokhlesin, M. (2019). Effect of whole body vibration with stretching exercise on active and passive range of motion in lower extremities in children with cerebral palsy: A randomized clinical trial. Iranian Journal of Pediatrics, 29(5), e84436.
Akuthota, V., Ferreiro, A., Moore, T., & Fredericson, M. (2008). Core stability exercise principles. Current sports medicine reports, 7(1), 39-44. https://doi.org/01.CSMR.0000308663.13278.69
Ali, M. S., & Abd El-Aziz, H. G. (2021). Effect of whole-body vibration on abdominal thickness and sitting ability in children with spastic diplegia. Journal of Taibah University Medical Sciences, 16(3), 379-386. https://doi.org/10.1016/j.jtumed.2020.11.006
Arpa, S., & Ozcakir, S. (2019). Does electromyographic biofeedback improve exercise effects in hemiplegic patients? A pilot randomized controlled trial. Journal of Rehabilitation Medicine, 51(2), 109-112. https://doi.org/10.2340/16501977-2513
Banky, M., Ryan, H. K., Clark, R., Olver, J., & Williams, G. (2017). Do clinical tests of spasticity accurately reflect muscle function during walking: A systematic review. Brain Injury, 31(4), 440-455. https://doi.org/10.1080/02699052.2016.1271455
Behrens, R., Gregoire, C., Mathern, T., & Pederson, J. L. (2006). An Electromyographic and Electrogoniometric Study of Stair Climbing with and without the Use of the Ez-Stepª and the Quad-Stepª. Physical Therapy Scholarly Projects, 42. https://commons.und.edu/pt-grad/42
Bilgili, F., Temelli, Y., & Akalan, N. E. (2012). Assessment of the hip and knee flexion contractures in cerebral palsy patients with crouch gait. JAREM. Journal of Academic Research in Medicine, 2(2), 33. https://doi.org/10.5152/jarem.2012.11
Boel, L., Pernet, K., Toussaint, M., Ides, K., Leemans, G., Haan, J., ... & Verhulst, S. (2019). Respiratory morbidity in children with cerebral palsy: an overview. Developmental Medicine & Child Neurology, 61(6), 646-653. https://doi.org/10.1111/dmcn.14060
Bottaro, A., Casadio, M., Morasso, P. G., & Sanguineti, V. (2005). Body sway during quiet standing: is it the residual chattering of an intermittent stabilization process? Human movement science, 24(4), 588-615. https://doi.org/10.1016/j.humov.2005.07.006
Briggs, A. M., Greig, A. M., Wark, J. D., Fazzalari, N. L., & Bennell, K. L. (2004). A review of anatomical and mechanical factors affecting vertebral body integrity. International Journal of Medical Sciences, 1(3), 170. https://doi.org/10.7150/ijms.1.170
Bryant, E., Pountney, T., Williams, H., & Edelman, N. (2013). Can a six-week exercise intervention improve gross motor function for non-ambulant children with cerebral palsy? A pilot randomized controlled trial. Clinical Rehabilitation, 27(2), 150-159. https://doi.org/10.1177/0269215512453061
Cavaggioni, L., Ongaro, L., Zannin, E., Iaia, F. M., & Alberti, G. (2015). Effects of different core exercises on respiratory parameters and abdominal strength. Journal of physical therapy science, 27(10), 3249-3253. https://doi.org/10.1589/jpts.27.3249
Chiba, R., Takakusaki, K., Ota, J., Yozu, A., & Haga, N. (2016). Human upright posture control models based on multisensory inputs; in fast and slow dynamics. Neuroscience research, 104, 96-104. https://doi.org/10.1016/j.neures.2015.12.002
Cho, I., Jeon, C., Lee, S., Lee, D., & Hwangbo, G. (2015). Effects of lumbar stabilization exercise on functional disability and lumbar lordosis angle in patients with chronic low back pain. Journal of physical therapy science, 27(6), 1983-1985. https://doi.org/10.1589/jpts.27.1983
Costantino, C., Petraglia, F., Sabetta, L. L., & Giumelli, R. (2018). Effects of single or multiple sessions of whole body vibration in stroke: is there any evidence to support the clinical use in rehabilitation? Rehabilitation research and practice, 2018, 8491859. https://doi.org/10.1155/2018/8491859
Czaprowski, D., Leszczewska, J., Kolwicz, A., Pawłowska, P., Kędra, A., Kriščiūnas, A., ... & Kowalski, I. M. (2013). The influence of self-stretching based on postisometrical relaxation, static stretching combined with stabilizing exercises, and stabilizing exercises only on the flexibility of one-joint and two-joint hip flexors. Medicina, 49(10), 69. https://doi.org/doi.org/10.3390/medicina49100069
Dickin, D. C., Faust, K. A., Wang, H., & Frame, J. (2013). The acute effects of whole-body vibration on gait parameters in adults with cerebral palsy. Journal of Musculoskeletal and Neuronal Interactions, 13(1), 19-26.
Dodd, K. J., Taylor, N. F., & Damiano, D. L. (2002). A systematic review of the effectiveness of strength-training programs for people with cerebral palsy. Archives of physical medicine and rehabilitation, 83(8), 1157-1164. https://doi.org/10.1053/apmr.2002.34286
Elshafey, A., Mahgoub, S.A. & Mohamed, M. (2021). Effect of whole-body vibration on spastic diplegic children. European Journal of Molecular & Clinical Medicine, 8(2), 1025.
Gloeckl, R., Heinzelmann, I., Baeuerle, S., Damm, E., Schwedhelm, A. L., Diril, M., ... & Kenn, K. (2012). Effects of whole body vibration in patients with chronic obstructive pulmonary disease–a randomized controlled trial. Respiratory medicine, 106(1), 75-83. https://doi.org/10.1016/j.rmed.2011.10.021
Gribble, P. A., & Hertel, J. (2003). Considerations for normalizing measures of the Star Excursion Balance Test. Measurement in physical education and exercise science, 7(2), 89-100. https://doi.org/10.1207/S15327841MPEE0702_3
Han, Y., Lee, S. & Yun C. (2019). The immediate influence of various whole-body vibration frequency on balance and walking ability in children with cerebral palsy: A pilot study. Journal of Exercise Rehabilitation, 15(4), 597-602. https://doi.org/10.12965/jer.1938318.159
Hoffmann, T. C., Glasziou, P. P., Boutron, I., Milne, R., Perera, R., Moher, D., ... & Michie, S. (2014). Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide. BMJ, 348. https://doi.org/10.1136/bmj.g1687
Jang, E. M., Kim, M. H., & Oh, J. S. (2013). Effects of a bridging exercise with hip adduction on the EMG activities of the abdominal and hip extensor muscles in females. Journal of physical therapy science, 25(9), 1147-1149. https://doi.org/10.1589/jpts.25.1147
Jeon, I. C., & Jang, J. H. (2017). Comparison of prone hip extension exercise and prone hip extension exercise after iliopsoas stretching on lumbopelvic control and gluteus maximus activity in subjects with short iliopsoas. Journal of Musculoskeletal Science and Technology, 1(1), 19-25. https://doi.org/10.29273/jkema.2017.1.1.19
Jin, Z. H., Kibler, W. B., Press, J., & Sciascia, A. (2008). The role of core stability in athletic function. Journal of Beijing Sport University, 12, 39.
Kendall, F.P., McCreary, E.K., Provance, P.G., Rodgers, M.M. & Romani, W.A. (2005). Muscles: Testing and function with posture and pain. Lippincott Williams & Wilkins, Baltimore.
Key, J. (2013). ‘The core’: understanding it, and retraining its dysfunction. Journal of bodywork and movement therapies, 17(4), 541-559. https://doi.org/10.1016/j.jbmt.2013.03.012
Kim, H. J., Chung, S., Kim, S., Shin, H., Lee, J., Kim, S., & Song, M. Y. (2006). Influences of trunk muscles on lumbar lordosis and sacral angle. European Spine Journal, 15(4), 409-414.
Kim, T. W., & Kim, Y. W. (2015). Effects of abdominal drawing-in during prone hip extension on the muscle activities of the hamstring, gluteus maximus, and lumbar erector spinae in subjects with lumbar hyperlordosis. Journal of physical therapy science, 27(2), 383-386. https://doi.org/10.1589/jpts.27.383
King, M. A. (2000). Functional stability for the upper quarter. International Journal of Athletic Therapy and Training, 5(2), 17-21. https://doi.org/10.1123/att.5.2.17
Kisner, C. & Colby, L. (2018). Therapeutic exercise: Foundations and techniques. F.A. Davis Company, Philadelphia.
Ko, M. S., Sim, Y. J., Kim, D. H., & Jeon, H. S. (2016). Effects of three weeks of whole-body vibration training on joint-position sense, balance, and gait in children with cerebral palsy: a randomized controlled study. Physiotherapy Canada, 68(2), 99-105. https://doi.org/10.3138/ptc.2014-77
Kwon, Y. H., & Lee, H. Y. (2015). Differences in respiratory pressure and pulmonary function among children with spastic diplegic and hemiplegic cerebral palsy in comparison with normal controls. Journal of physical therapy science, 27(2), 401-403. https://doi.org/10.1589/jpts.27.401
Lahtinen, U., Rintala, P., & Malin, A. (2007). Physical performance of individuals with intellectual disability: A 30-year follow-up. Adapted physical activity quarterly, 24(2), 125-143. https://doi.org/10.1123/apaq.24.2.125
Lee, B. K., & Chon, S. C. (2013). Effect of whole body vibration training on mobility in children with cerebral palsy: a randomized controlled experimenter-blinded study. Clinical Rehabilitation, 27(7), 599-607. https://doi.org/10.1177/0269215512470673
Lee, L. W., Kerrigan, D. C., & Della Croce, U. (1997). Dynamic implications of hip flexion contractures1. American journal of physical medicine & rehabilitation, 76(6), 502-508.
Lewis, C. L., Sahrmann, S. A., & Moran, D. W. (2007). Anterior hip joint force increases with hip extension, decreased gluteal force, or decreased iliopsoas force. Journal of biomechanics, 40(16), 3725-3731. https://doi.org/10.1016/j.jbiomech.2007.06.024
Li, Y., Chen, X., Zhang, X., & Zhou, P. (2014). Several practical issues toward implementing myoelectric pattern recognition for stroke rehabilitation. Medical Engineering & Physics, 36(6), 754-760. https://doi.org/10.1016/j.medengphy.2014.01.005
Liebenson, C., Karpowicz, A. M., Brown, S. H., Howarth, S. J., & McGill, S. M. (2009). The active straight leg raise test and lumbar spine stability. PM&R, 1(6), 530-535. https://doi.org/10.1016/j.pmrj.2009.03.007
Lima, P. O., Oliveira, R. R., Moura Filho, A. G., Raposo, M. C., Costa, L. O., & Laurentino, G. E. (2012). Concurrent validity of the pressure biofeedback unit and surface electromyography in measuring transversus abdominis muscle activity in patients with chronic nonspecific low back pain. Brazilian Journal of Physical Therapy, 16, 389-395. https://doi.org/10.1590/S1413-35552012005000038
Magee, D.J. & Manske, R.C. (2020). Orthopedic physical assessment. Saunders Publication, Philadelphia.
Malai, S., Pichaiyongwongdee, S., & Sakulsriprasert, P. (2015). Immediate Effect of Hold-Relax Stretching of Iliopsoas Muscle on Transversus Abdominis Muscle Activation in Chronic Non-Specific Low Back Pain with Lumbar Hyperlordosis. Journal of the Medical Association of Thailand, 98, S6-11.
Marín, P. J., & Rhea, M. R. (2010). Effects of vibration training on muscle power: a meta-analysis. The Journal of Strength & Conditioning Research, 24(3), 871-878. https://doi.org/10.1519/JSC.0b013e3181c7c6f0
McGill, S. (2002). Low back disorders: evidence-based prevention and rehabilitation. Champaign, IL, Human Kinetics.
Mills, J. D., Taunton, J. E., & Mills, W. A. (2005). The effect of a 10-week training regimen on lumbo-pelvic stability and athletic performance in female athletes: a randomized-controlled trial. Physical Therapy in Sport, 6(2), 60-66. https://doi.org/10.1016/j.ptsp.2005.02.006
Miyake, Y., Kobayashi, R., Kelepecz, D., & Nakajima, M. (2013). Core exercises elevate trunk stability to facilitate skilled motor behavior of the upper extremities. Journal of bodywork and movement therapies, 17(2), 259-265. https://doi.org/10.1016/j.jbmt.2012.06.003
Mohamed, R. A., Abd El Aziz, A. S., & El Sayed, H. M. (2019). Effect of Whole Body Vibration versus Suspension Therapy on Balance and Functional Capacity in Children with Diplegic Cerebral Palsy. Journal PharmTech, International Journal, 12(1), 80-89.
Mohamed, R. A., El Sayed, H. M., Habshy, S. M., & Aly, S. M. (2021). Impact of two different pulmonary rehabilitation methods in children with down syndrome. Journal of Bodywork and Movement Therapies, 27, 512-521. https://doi.org/10.1016/j.jbmt.2021.04.009
Moher, D., Hopewell, S., Schulz, K. F., Montori, V., Gøtzsche, P. C., Devereaux, P. J., ... & Altman, D. G. (2012). CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. International journal of surgery, 10(1), 28-55. https://doi.org/10.1016/j.ijsu.2011.10.001
Mustafaoglu, R., Demir, R., Demirci, A. C., & Yigit, Z. (2019). Effects of core stabilization exercises on pulmonary function, respiratory muscle strength, and functional capacity in adolescents with substance use disorder: Randomized controlled trial. Pediatric pulmonology, 54(7), 1002-1011. https://doi.org/10.1002/ppul.24330
Norris, C. M. (2001). Functional load abdominal training: part 1. Physical Therapy in Sport, 2(1), 29-39. https://doi.org/10.1054/ptsp.2000.0032
Oh, D. S., & Park, S. E. (2016). The effect of lumbar stabilization exercise on the pulmonary function of stroke patients. Journal of Physical Therapy Science, 28(6), 1896-1900. https://doi.org/10.1589/jpts.28.1896
Oh, J. S., Cynn, H. S., Won, J. H., Kwon, O. Y., & Yi, C. H. (2007). Effects of performing an abdominal drawing-in maneuver during prone hip extension exercises on hip and back extensor muscle activity and amount of anterior pelvic tilt. Journal of orthopaedic & sports physical therapy, 37(6), 320-324. https://doi.org/10.2519/jospt.2007.2435
O'Leary, S., Jull, G., Kim, M., & Vicenzino, B. (2007). Specificity in retraining craniocervical flexor muscle performance. Journal of orthopaedic & sports physical therapy, 37(1), 3-9. https://doi.org/10.2519/jospt.2007.2237
Park, S. J., Lee, J. H., & Min, K. O. (2017). Comparison of the effects of core stabilization and chest mobilization exercises on lung function and chest wall expansion in stroke patients. Journal of physical therapy science, 29(7), 1144-1147. https://doi.org/10.1589/jpts.29.1144
Park, Y. J., Park, S. W., & Lee, H. S. (2018). Comparison of the effectiveness of whole body vibration in stroke patients: a meta-analysis. BioMed Research International, 2018, 5083634. https://doi.org/10.1155/2018/5083634
Pessoa, M. F., Brandão, D. C., Sá, R. B. D., Barcelar, J. D. M., Rocha, T. D. D. S., Souza, H. C. M. D., & Dornelas de Andrade, A. (2017). Vibrating platform training improves respiratory muscle strength, quality of life, and inspiratory capacity in the elderly adults: A randomized controlled trial. The Journals of Gerontology: Series A, 72(5), 683-688. https://doi.org/10.1093/gerona/glw123
Pleguezuelos, E., Casarramona, P., Guirao, L., Samitier, B., Ortega, P., Vila, X., ... & Miravitlles, M. (2018). How whole-body vibration can help our COPD patients. Physiological changes at different vibration frequencies. International journal of chronic obstructive pulmonary disease, 13, 3373. https://doi.org/10.2147/COPD.S165058
Radziszewski, K. R. (2007). Physical exercise in treatment of patients with lumbar discopathy. Ortopedia, traumatologia, rehabilitacja, 9(1), 98-106.
Richardson, C.A., Hodges, P. & Hides, J. (2004). Therapeutic exercise for lumbopelvic stabilization: a motor control approach for the treatment and prevention of low back pain, Edinburgh, Churchill, Livingstone.
Roelants, M., Verschueren, S. M., Delecluse, C., Levin, O., & Stijnen, V. (2006). Whole-body-vibration-induced increase in leg muscle activity during different squat exercises. Journal of strength and conditioning research, 20(1), 124.
Rosenbaum, P., Paneth, N., Levinton, A., Goldstein, M., Bax, M., Damiano, D., & Jacobsson, B. (2006). The definition and classification of cerebral palsy. NeoReviews, 7(11), e569. https://doi.org/10.1542/neo.7-11-e569
Roussouly, P., Gollogly, S., Berthonnaud, E., & Dimnet, J. (2005). Classification of the normal variation in the sagittal alignment of the human lumbar spine and pelvis in the standing position. Spine, 30(3), 346-353. https://doi.org/10.1097/01.brs.0000152379.54463.65
Ruas, C. V., Brown, L. E., Lima, C. D., Costa, P. B., & Pinto, R. S. (2018). Effect of three different muscle action training protocols on knee strength ratios and performance. The Journal of Strength & Conditioning Research, 32(8), 2154-2165. https://doi.org/10.1519/JSC.0000000000002134
Starr, J., Dalton, D., Cynthia, C. & Pamela, K. (2011). Joint structure and function, FA Davis Company, Philadelphia.
Sterba, J. A., Rogers, B. T., France, A. P., & Vokes, D. A. (2002). Horseback riding in children with cerebral palsy: effect on gross motor function. Developmental Medicine and Child Neurology, 44(5), 301-308. https://doi.org/10.1017/S0012162201002122
Strongoli, L. M., Gomez, C. L., & Coast, J. R. (2010). The effect of core exercises on transdiaphragmatic pressure. Journal of sports science & medicine, 9(2), 270.
Sumners, D. P., Green, D. A., Mileva, K. N., & Bowtell, J. L. (2008). Increases in inspiratory neural drive in response to rapid oscillating airflow braking forces (vibration). Respiratory physiology & neurobiology, 160(3), 350-352. https://doi.org/10.1016/j.resp.2007.10.005
Tang-Wai, R., Webster, R. I., & Shevell, M. I. (2006). A clinical and etiologic profile of spastic diplegia. Pediatric neurology, 34(3), 212-218. https://doi.org/10.1016/j.pediatrneurol.2005.08.027
Tayashiki, K., Maeo, S., Usui, S., Miyamoto, N., & Kanehisa, H. (2016). Effect of abdominal bracing training on strength and power of trunk and lower limb muscles. European journal of applied physiology, 116(9), 1703-1713. https://doi.org/10.1007/s00421-016-3424-9
Tecklin, J. (2014). Pediatric physical therapy, Philadelphia: Lippincott Williams &Wilkins, Wolter Kluwer.
Tupimai, T., Peungsuwan, P., Prasertnoo, J., & Yamauchi, J. (2016). Effect of combining passive muscle stretching and whole body vibration on spasticity and physical performance of children and adolescents with cerebral palsy. Journal of physical therapy science, 28(1), 7-13. https://doi.org/10.1589/jpts.28.7
Unger, M., Faure, M., & Frieg, A. (2006). Strength training in adolescent learners with cerebral palsy: a randomized controlled trial. Clinical Rehabilitation, 20(6), 469-477. https://doi.org/10.1191/0269215506cr961oa
Uyanik, M., & Kayihan, H. (2010). Down syndrome: sensory integration, vestibular stimulation and neurodevelopmental therapy approaches for children. Stone JH, Blouin M. International Encyclopedia of Rehabilitation, 9.
Vaz, G., Roussouly, P., Berthonnaud, E., & Dimnet, J. (2002). Sagittal morphology and equilibrium of pelvis and spine. European spine journal, 11(1), 80-87. https://doi.org/10.1007/s005860000224
Willson, J. D., Dougherty, C. P., Ireland, M. L., & Davis, I. M. (2005). Core stability and its relationship to lower extremity function and injury. JAAOS-Journal of the American Academy of Orthopaedic Surgeons, 13(5), 316-325.
Wolf, S. L., Blanton, S., Baer, H., Breshears, J., & Butler, A. J. (2002). Repetitive task practice: a critical review of constraint-induced movement therapy in stroke. The neurologist, 8(6), 325. https://doi.org/10.1097/01.nrl.0000031014.85777.76
Woodford, H. J., & Price, C. I. (2007). EMG biofeedback for the recovery of motor function after stroke. Cochrane Database of Systematic Reviews, (2). https://doi.org/10.1002/14651858.CD004585
Woollacott, M. H., & Shumway-Cook, A. (2005). Postural dysfunction during standing and walking in children with cerebral palsy: what are the underlying problems and what new therapies might improve balance? Neural plasticity, 12(2-3), 211-219. https://doi.org/10.1155/NP.2005.211
Xu, C., Fu, Z., & Wang, X. (2021). Effect of Transversus abdominis muscle training on pressure-pain threshold in patients with chronic low Back pain. BMC Sports Science, Medicine and Rehabilitation, 13(1), 1-15. https://doi.org/10.1186/s13102-021-00262-8
The works and papers that are published in this Journal are subject to the following terms:
1. The Publication Service of the University of Murcia (the publisher) has the Publication Rights (Copyright) to the published papers and works, and favors and permits the reusing of the same under the license indicated in point 2.
© Servicio de Publicaciones, Universidad de Murcia, 2013
2. The papers and works are to be published in the digital edition of the Journal under the license Creative Commons Reconocimiento-No Comercial-Sin Obra Derivada 3.0 España (legal text). The copying, using, spreading, transmitting and publicly displaying of the papers, works or publication are permitted as long as: i) the authors and original sources (Journal, publisher and URL of the publication) are quoted; ii) it is not used for commercial benefit; iii) the existence and specifications of this users license are mentioned.
3. Conditions of Self-Archiving. It is permitted and encouraged that the authors spread electronically the pre-print (before printing) and/or post-print (the revised, evaluated and accepted) versions of their papers or works before their publication since this favors their circulation and early diffusion and therefore can help increase their citation and quotation, and also there reach through the academic community.
The works and papers that are published in this Journal are subject to the following terms:
1. The Publication Service of the University of Murcia (the publisher) has the Publication Rights (Copyright) to the published papers and works, and favors and permits the reusing of the same under the license indicated in point 2.
© Servicio de Publicaciones, Universidad de Murcia, 2013
2. The papers and works are to be published in the digital edition of the Journal under the license Creative Commons Reconocimiento-No Comercial-Sin Obra Derivada 3.0 España (legal text). The copying, using, spreading, transmitting and publicly displaying of the papers, works or publication are permitted as long as: i) the authors and original sources (Journal, publisher and URL of the publication) are quoted; ii) it is not used for commercial benefit; iii) the existence and specifications of this users license are mentioned.
3. Conditions of Self-Archiving. It is permitted and encouraged that the authors spread electronically the pre-print (before printing) and/or post-print (the revised, evaluated and accepted) versions of their papers or works before their publication since this favors their circulation and early diffusion and therefore can help increase their citation and quotation, and also there reach through the academic community.