Introduction: studying the influence of surfing on the prevalence of injuries may contribute to prevention. Objective: to analyze the influence of time practicing sports and the occurrence of previous surgery on the profile and prevalence of injuries caused by surfing. Methods: Sixty-six Brazilian surfers (26.16 ± 0.73 years old) participated in this study. Anthropometric data, physical activity level, surfing practice time and the prevalence of injuries (type of injury, anatomical region affected, and mechanism of injury) were evaluated. To assess which of the studied variables exerted significant influence on the mean number of injuries, a Poisson log-linear model was adjusted through R software (p < 0.05). Results: most surfers were classified as eutrophic (73%), very active (60.6%), had an average practice time of 10.1 ± 1 years, and were not members of a surfing federation (74%). It was also observed that 90.9% of participants reported injuries caused by surfing and 44.9% affected the lower limbs. The majority of these injuries affected the integumentary system (46.6%). The main mechanism of injury was impact with the board or seabed (40.4%). Furthermore, it was found that surfing federation members presented an average of 58.4% more injuries than non-members (p = 0.007). Surfers who had undergone previous surgeries showed an average number of injuries that was 56.9% higher than other surfers (p = 0.012). In addition, it was found that for each extra year of surfing, the average number of injuries increased by 2.5% (p = 0.0118). Conclusion: the average number of injuries increased with increment in time practicing the sport, previous surgery and membership in a surfing federation.

| Although surfing can contribute to chronic low back pain, the relationship between functional/kinetic changes and low back pain are still not fully understood.The association between low back pain and functional/ kinetic aspects was investigated in people who had surfed for different numbers of years, in a cross-sectional study involving 66 surfers from the coast of Paraná. The participants were allocated into three groups considering how long they had surfed: G1 (up to 4.9 years), G2 (from 5 to 9.9 years) and G3 (more than 10 years). The following items were evaluated: body mass index; level of physical activity; low back pain; intensity and frequency of low back pain, low back disability, low back function, low back flexibility, low back range of motion, low back and thoracic angles. To analyze the association between functional/ kinetic aspects and low back pain, Pearson's Qui-Square test was used for categorical data, while for nominal data ANOVA with Bonferroni's post-hoc test (p<0.05) was used.The group which had surfed the longest (G3) showed an association with the occurrence of low back pain (p=0.05) and its highest intensity (p=0.01). The group with 5 to 9.9 years of surfing (G2) showed the largest low back angle (p=0.04). We conclude that the surfer's chronic low back Se dividieron a los participantes en tres grupos según su tiempo, en años, de práctica deportiva: G1 (hasta 4,9 años), G2 (de 5 a 9,9 años) y G3 (más de 10 años). Se evaluaron: el índice de masa corporal, el nivel de actividad física, la presencia de dolor lumbar, la intensidad y periodicidad del dolor, la incapacidad lumbar, la funcionalidad lumbar, la flexibilidad lumbar, la amplitud del movimiento lumbar, el ángulo torácico y lumbar. Para analizar la asociación de los aspectos cinético y funcional con el dolor lumbar se empleó la prueba de chi-cuadrado de Pearson para los datos categóricos y para los datos nominales la prueba ANOVA con post-hoc, de Bonferroni (p<0,05). El mayor tiempo de práctica deportiva (G3) fue asociado con la presencia (p=0,05) y mayor intensidad del dolor lumbar (p=0,01). El grupo que practicaba de 5 a 9,9 años (G2) este deporte presentó mayor ángulo lumbar (p=0,04). Se concluye que la presencia de dolor lumbar crónica en surfistas estuvo asociada con la intensidad del dolor, el ángulo de la columna lumbar y el tiempo de práctica del surf.Palabras clave | Deportes; Dolor Lumbar; Curvaturas de la Columna Vertebral; Traumatismos en Atletas; Lordosis.