[1. Chodzko-Zajko W.J., Proctor D.N., Fiatarone Singh M.A., Minson C.T., Nigg C. R., Salem G.J., Skinner J.S. (ACSM) (2009). Exercise and Physical Activity for Older Adults, Medicine & Science in Sports & Exercise, 41(7):1510-1530.10.1249/MSS.0b013e3181a0c95c]Search in Google Scholar
[2. Borras X., Comella A., Marín F., Comella R.R., Cirera, E. (2007) Aplicabilidad de la goniometría mediante videografía en el seguimiento de programas de flexibilidad, Biomecánica, 15(1):28-33.10.5821/sibb.v15i1.1757]Search in Google Scholar
[3. Kanásová J. (2008). Reducing shortened muscles in 10-12-year-old boys through a physical exercise program, Medicina Sportiva, 12:115-123.10.2478/v10036-008-0022-x]Search in Google Scholar
[4. Sainz de Baranda P., Rodríguez P.L., Santonja F.M., López-Miñarro P.A., Andujar P., Ferrer V., Pastor A. (2006). Effects of hamstring stretching exercises on the toe-touch test in elementary schoolchildren, Journal of Human Movement Studies, 51(4):277-289.]Search in Google Scholar
[5. Santonja F., Rodríguez P.L., Sainz de Baranda P., López Miñarro P.A. (2004). Papel del profesor de educación física ante las desalineaciones de la columna vertebral, Selección, 13(1):5-17.]Search in Google Scholar
[6. Brodersen A., Pedersen B., Reimers J. (1994). Incidence of complaints about heel, knee and back related discomfort among Danish children, possible relation to short muscles, Ugeskrift fot Laeger, 156:2243-2245.]Search in Google Scholar
[7. Harreby M., Neergaard K., Jessen T., Larsen E., Storr-Paulsen A., Lindahl A., Fisker I., Laegaard E. (1999). Risk factors for low back pain in a cohort of 1389 Danish school children an epidemiologic study, European Spine Journal, 8:444-450.10.1007/s005860050203]Search in Google Scholar
[8. Rodríguez P.L., Santonja F.M., López-Miñarro P.A., Sáinz de Baranda J.L., Yuste J. L. (2008). Effect of physical education stretching program on sit-and-reach score in schoolchildren, Science & Sports, 23(3-4):170-175.10.1016/j.scispo.2007.12.013]Search in Google Scholar
[9. Penha P.J., Amado Joäo S.M. (2008). Muscle flexibility assessment among boys and girls aged 7 and 8 years old, Fisioterapia e Pesquisa, 15(4):387-391.]Search in Google Scholar
[10. Cabry J., Shiple B., J. (2000). Increasing hamstring flexibility decreases hamstring injuries in high school athletes, Clinical Journal of Sport Medicine, 10:311-312.10.1097/00042752-200010000-00029]Search in Google Scholar
[11. Kendall F.P., McCreary E.K., Provance P.G., Rodgers M.M. Romani W.A. (2005). Muscles: Testing and function with posture and pain, 5th edition, Lippincott, Williams, & Wilkins, Baltimore.]Search in Google Scholar
[12. Esola M.A., McClure P.W., Fitzgerald G.K. Siegler S. (1996). Analysis of lumbar spine and hip motion during forward bending in subjects with and without a history of low back pain, Spine, 21:71-78.10.1097/00007632-199601010-00017]Search in Google Scholar
[13. López-Miñarro P.A., Muyor J.M., Alacid F. (2012). Influence of hamstring extensibility on sagittal spinal curvatures and pelvic tilt in high-trained young kayakers, European Journal of Sport Science, 12(6):469-474.10.1080/17461391.2011.575476]Search in Google Scholar
[14. Feldman D.E., Shrier I., Rossignol M., Abenhaim L. (2001). Risk factors for the development of low back pain in adolescence, American Journal of Epidemiology, 154(1):30-36.10.1093/aje/154.1.30]Search in Google Scholar
[15. Standaert C.J., Herring S. A. (2000). Spondylolysis: A critical review, British Journal of Sports Medicine, 34:415-422.10.1136/bjsm.34.6.415]Search in Google Scholar
[16. Kayser R., Mahlfeld K., Heyde C.E., Grasshoff H., Mellerowicz, H. (2006). Tight hamstring syndrome and extra or intraspinal diseases in childhood: a multicenter study, European Spine Journal, 15(4):403-408.10.1007/s00586-005-0886-6]Search in Google Scholar
[17. Royal Decree 126/2014, the 28th February, laying down the Curriculum for Primary Education, Government Gazette, 52, 19349-19420.]Search in Google Scholar
[18. Coledam D.H.C., Arruda G.A., Ramos de Oliveira A. (2012). Chronic effect of static stretching performed during warm-up on flexibility in children, Revista Brasileira de Cineantropometria e Desempenho Humano, 14:296-304.10.5007/1980-0037.2012v14n3p296]Search in Google Scholar
[19. Benito Peinado P.J., Díaz Molina V., Calderón Montero F.J., Peinado Lozano A.B., Martín Caro C., Álvarez Sánchez M., Pérez Tejero J. (2007). Literature review in exercise physiology: Practical recommendations, Revista Internacional de Ciencias del Deporte, 6:1-11.10.5232/ricyde2007.00601]Search in Google Scholar
[20. Santonja F., Sainz de Baranda P., Rodríguez P. L., López P.A. Canteras M. (2007). Effects of frequency of static stretching on straight leg raise in elementary school children, Journal of Sports Medicine and Physical Fitness, 47(3):304-308.]Search in Google Scholar
[21. Rodríguez García P.L., Santonja Medina F., Canteras Jornada M., Delgado Fernández M., Fernández Piñera J., Balsalobre Marín J. (1999). Mejora de la extensibilidad isquiosural tras un programa escolar de estiramientos, Selección, 8(4):157-164.]Search in Google Scholar
[22. Castro-Piñero J., Chillón P., Ortega F.B., Montesinos J.L., Sjöström M. Ruiz, J.R. (2009). Criterion-related validity of sit-and-reach and modified sit-and-reach test for estimating hamstring flexibility in children and adolescents aged 6-17 years, International Journal of Sports Medicine, 30:658-662.10.1055/s-0029-1224175]Search in Google Scholar
[23. López Miñarro P.A., Sainz de Baranda P., Yuste Lucas J.L., Rodríguez García P.L. (2008). Validity of the unilateral sit-and-reach test as measure of hamstring muscle extensibility. Comparison with other protocols, Cultura, Ciencia y Deporte, 3:87-92.]Search in Google Scholar
[24. Mayorga-Vega D., Merino-Marban R., Viciana J. (2014a). Criterion-related validity of sit-and-reach tests for estimating hamstring and lumbar extensibility: A meta-analysis, Journal of Sports Science and Medicine, 13(1):1-14.10.4100/jhse.2014.91.18]Search in Google Scholar
[25. Sánchez Rivas E., Mayorga-Vega D., Fernández-Rodríguez E., Merino-Marbán R. (2014). Effect of a hamstring stretching program during physical education lessons in primary education, Journal of Sport and Health Research, 6(2):159-168.]Search in Google Scholar
[26. Merino-Marban R., Mayorga-Vega D., Fernandez-Rodriguez E., Vera Estrada F., Viciana J. (2015). Effect of a physical education-based stretching programme on sit-and-reach score and its posterior reduction in elementary schoolchildren, European Physical Education Review 21(1):83-92.10.1177/1356336X14550942]Search in Google Scholar
[27. Mayorga-Vega D., Merino-Marban R., Garrido F. J., Viciana J. (2014b). Comparison between warm-up and cool-down stretching programs on hamstring extensibility gains in primary schoolchildren, Physical Activity Review, 2:16-24.]Search in Google Scholar
[28. Faigenbaum A.D., Belluci M., Bernieri A., Bakker B., Hoorens K. (2005). Acute effects of different warm-up protocols on fitness performance in children, Journal of Strength and Conditioning Research, 19:376-381.10.1519/00124278-200505000-00023]Search in Google Scholar
[29. Gelen E. (2011). Acute effects of different warm-up methods on jump performance in children, Biology of Sport, 28:133-138.10.5604/947456]Search in Google Scholar
[30. Duncan M.J., Woodfield L.A. (2006). Acute effects of warm up protocol on flexibility and vertical jump in children, Journal of Exercise Physiology online, 9:9-16.]Search in Google Scholar
[31. Needham R.A., Morse C.I., Degens H. (2009). The acute effect of different warm-up protocols on anaerobic performance in elite youth soccer players, Journal of Strength and Conditioning Research, 23:2614-2620.10.1519/JSC.0b013e3181b1f3ef]Search in Google Scholar
[32. Di Cagno A., Baldari C., Battaglia C., Gallotta M.C., Videira M., Piazza M., Guidetti L. (2010). Pre-exercise static stretching effect on leaping performance in elite rhythmic gymnasts, Journal of Strength and Conditioning Research, 24:1995-2000.10.1519/JSC.0b013e3181e34811]Search in Google Scholar
[33. Reid D.A. McNair P. J. (2004). Passive force, angle and stiffness changes after stretching of hamstring muscles, Medicine and Science in Sports and exercise, 36:1944-1948.10.1249/01.MSS.0000145462.36207.20]Search in Google Scholar
[34. Nelson R.T. Bandy W.D. (2004). Eccentric training and static stretching improve hamstring flexibility of high school males., Journal of Athletic Training, 39:254-258.]Search in Google Scholar
[35. Mayorga-Vega D., Merino-Marban R., Sánchez-Rivas E., Viciana J. (2014c). Effect of a short-term static stretching training program followed by five weeks of detraining on hamstring extensibility in children aged 9-10 years, Journal of Physical Education and Sport, 14(3):355–359.]Search in Google Scholar
[36. Mayorga-Vega D., Merino-Marban R., Vera-Estrada F., Viciana J. (2014d). Effect of a short-term physical education-based flexibility program on hamstring and lumbar extensibility and its posterior reduction in primary schoolchildren, Kinesiology, 46(2):227-233.]Search in Google Scholar
[37. Cipriani D.J., Terry M.E., Haines M.A., Tabibnia A.P., Lysanova O.(2012). Effect of stretch frequency and sex on the rate of gain and rate of loss in muscle flexibility during a hamstring-stretching program: A randomized single-blind longitudinal study, Journal of Strength and Conditioning Research, 26(8):2119–2129.10.1519/JSC.0b013e31823b862a]Search in Google Scholar
[38. Rancour J., Holmes CF., Cipriani DJ. (2009). The effects of intermittent stretching following a 4-week static stretching protocol: A randomized trial, Journal of Strength and Conditioning Research, 23(8):2217–2222.10.1519/JSC.0b013e3181b869c7]Search in Google Scholar
[39. Willy R.W., Kyle B.A., Moore S.A., Chleboun G.S. (2001). Effect of cessation and resumption of static hamstring muscle stretching on joint range of motion, Journal of Orthopaedic and Sports Physical Therapy, 31(3):138–144.10.2519/jospt.2001.31.3.138]Search in Google Scholar
[40. Mayorga-Vega D., Merino-Marban R., Real J., Viciana J. (2015). A physical education-based stretching program performed once a week also improves hamstring extensibility in schoolchildren: a cluster-randomized controlled trial, Nutricion Hospitalaria, 32(4):1715-1721.]Search in Google Scholar