Introduction
Physically impaired people frequently need assistance to perform activities of daily living and compete in sport.1 Blind athletes, for example, require assistance from a sighted guide. The organisation, identification and interpretation of sensory inputs to represent and understand one’s surroundings are among the most important basic psychological processes.2–7
Space, like time, is not an innate notion. In sport, athletes slowly become aware of their surroundings through an initial perception of their bodies in space and the ensuing changes that occur, such as motor and sensory responses. Conceptualisation of position, location, direction and distance is necessary for efficient motor performance.8 9 Spatial representation in blind people, however, is a slower, more complex process that requires accurate information and adequate training.
Space is generally perceived from the position of an object in space, and the information needed for processing this is usually provided by vision, touch or kinesthetic senses. The understanding of space is additionally complemented by the orientation of the person’s body in relation to the surrounding physical space. Spatial perceptual skills encompass the ability to determine the position of one’s body and objects in space, the ability to use spatial references, and the ability to successfully navigate this space.10 11
People are considered blind when they have total vision loss or light perception only; they have a visual acuity of 0.05 or less and a field radius of less than 10°.8 The International Paralympic Committee classifies visually impaired athletes into three sport classes known as T/F11–12–13. Those with the most severe visual impairment (ie, very low visual acuity and/or no light perception) are included in sport class T/F11.12 13
Long jump has featured as a paralympic sport since 1976.14 All athletes are required to wear opaque glasses or equivalent during competition to ensure equal level of visual impairment.15 They thus need to follow the instructions of a sighted guide in their approach to the jump, which ends in a pit measuring 1.00 m×1.22 m.12 The approach, or run-up, is one of the key components of a successful jump. It is largely dependent on consistency of stride length, number of strides and the achievement of an optimal speed just before take-off.16–26
Sighted athletes can adjust their approach during the final phase of the run-up; blind athletes, however, cannot make this visual adjustment, and it could therefore be hypothesised that any changes in final strides would be the result of training targeting the take-off action, with no adjustments in final approach.27 28
The aim of this study was to determine the spatiotemporal characteristics of long jumps performed by blind athletes in the F11 sport class at the Paralympic Games in London, with a focus on variables corresponding to the last three strides taken before take-off and a comparison with findings reported for sighted long jumpers.
Ethical considerations
The study was approved by the bioethics committee at the University of Barcelona (IRB00003099). Anonymity was guaranteed, and the study was conducted in full compliance with the principles of the fifth revision of the Declaration of Helsinki of the World Medical Association (October 2000).