[en] INTRODUCTION: Cerebral palsy (CP) is the main cause of disability in childhood. Among its most prominent and limiting symptoms includes muscle weakness, spasticity and motor control deficits. Muscle strengthening work is increasingly more frequently applied in rehabilitation of this type of patient, however, it has historically been a susceptible subject of controversy for its possible link to increase spasticity. Systematic reviews have not conducted a thorough analysis to provide conclusive data. OBJECTIVE: Determine if muscle strengthening programs have negative effects on spasticity in patients with CP. In addition, it seeks to understand the behavior of muscle strength after application of these programs, maintenance of changes over time and the possible discovery of other adverse effects. MATERIALS AND METHODS: The information search was conducted in the databases of health sciences PubMed, PEDro, CINAHL and Scopus between the months of March and May 2016. The methodological quality of the selected articles was assessed with the PEDro scale. RESULTS: a total of 8 articles that met the established criteria, presenting an average score of 4 out of 10 points on the PEDro scale, were selected. In 6 of them, no changes were found in spasticity between pre- and post-training measurements. Two articles if small changes were recorded in the same corresponding to increase, however these were not maintained over time in subsequent measurements at the end of the program. Muscle strength improved in all controlled trials compared to the control group, as well as in clinical trials were not provided for this group. The values of isometric and concentric force showed more significant improvements. The eccentric force was analyzed in two similar articles getting mixed results. The changes obtained were maintained for at least 4 weeks after the intervention, and could not confirm any adverse effects significantly. CONCLUSIONS: strong evidence that muscle strength training has no negative long-term effects on spasticity was found. Moderate evidence of improved for isometric strength and strong evidence for concentric strength was found after undergoing complete programs; however, the same evidence was not found for the eccentric strength. There is strong evidence that changes on muscle strength are maintained over time.

[gl] INTRODUCCIÓN: A parálise cerebral infantil é a principal patoloxía causante de discapacidade durante a infancia. Entre os seus síntomas mási destacados e limitantes atópanse a debilidade muscular, a espasticidade e o déficit de control motor. O traballo de fortalecemento muscular é aplicado cada vez con máis frecuencia neste tipo de pacientes, sin embargo, históricamente veu sendo un tema susceptible de controversia pola sua posible relación cun aumento na espasticidade. Ninguna revisión sistemática realizou unha análise exhaustiva que aportase datos concluíntes. OBXECTIVO: Coñecer se os programas de fortalecemento muscular teñen efectos negativos sobre a espasticidade en pacientes con PCI. Ademáis, búscase coñecer o comportamento da forza muscular tras a aplicación deste tipo de programas, o mantemento dos cambios rexistrados no tempo e o posible achado doutros efectos adversos. MATERIAL E MÉTODOS: A busca de información realizouse nas bases de datos de ciencias da saúde Pubmed, PEDro, CINAHL e Scopus entre os meses de marzo e maio de 2016. A calidade metodolóxica foi evaluada coa escala PEDro. RESULTADOS: foron seleccionados un total de 8 artículos que cumpriran os criterios establecidos, presentando una puntuación de 4 sobre 10 puntos na escala PEDro. En 6 deles, non se atoparon cambios na espasticidade entre as medición pre- e post- adestramento. Dous artículos rexistraron pequenos cambios na mesma, sen embargo estes non se mantiveron no tempo en medicións posteriores ao remate do programa. A forza muscular mellorou en todos os ensaios controlados con respecto ao grupo control, así como nos ensayon clínicos que non dispuxeron deste grupo. Os valores de forza isométrica e concéntrica mostraron mellorías significativas. A forza excéntrica foi analizada por 2 artículos similares obtendo resultados dispares. Os cambios obtidos mantiveronse polo menos 4 semanas despois da intervención, sen confirmarse efectos adversos. CONCLUSIÓNS: Atopouse evidencia forte de que o adestramento da forza muscular non ten efectos negativos sobre a espasticidade a largo prazo. Existe evidencia moderada da melloría sobre a forza isométrica e evidencia forte sobre a forza concéntrica tras someterse aos programas completos; sen embargo, esta mesma evidencia non se atopou para a forza excéntrica. Existe evidencia forte de que os cambios obtidos sobre a forza muscular se manteñen no tempo.