Coordinative characterization of front crawl swimmers with Down syndrome

Objective: Literature regarding the performance of swimmers with mental disabilities is scarce. Thus, it was purposed to carry out a Down syndrome characterization on front crawl swimming, examining several parameters: velocity, intra-cyclic velocity fluctuation, arm coordination, propelling efficiency and stroke parameters. Design: Six international level Down syndrome swimmers performed a 20 m maximal intensity front crawl bout. Video analysis was used to assess intra-cyclic velocity fluctuation of the hip, arm coordination and propelling efficiency. Results: It was observed that velocity, stroke rate, stroke length, index of coordination and propelling efficiency were lower for swimmers with Down syndrome when compared to the literature for swimmers without disabilities, which seems to reflect the lower coordinative development and technical efficiency of people with Down syndrome. However, these swimmers presented a direct relationship between velocity and stroke length (r=0.83, p<0.05) and between index of coordination and stroke rate (r=0.90, p<0.05), as is presented in the literature for swimmers without disabilities. Additionally, intra-cyclic velocity fluctuation was higher in swimmers with Down syndrome, evidencing an inability to maintain continuous propulsive actions. This fact is also evidenced by their catch-up coordination mode (negative index of coordination) that is typical for normal young stages of development. Conclusions: These findings suggest that lower swimming ability is evident in Down syndrome swimmers when compared with swimmers without disability. However, our subjects are involved in a training program and therefore probably more able to better perform activities of daily living when compared with other Down syndrome subjects, since coordination is a requirement for the training program. In addition, coordination is essential to maintain physical independence.