Spatial references
Spatial organization is essential for skiing actions, so we need precise references for that. Space is perceived through visual references that provide support for spatial orientation and path control, which allows us locating objects and people, calculate distances, and determine spatial positions on topographic surfaces like ski slopes.
These references are directional invariants built on combined or pondered sensory information by the activity of the individual, filtering its previous motor and cognitive experiences (Isableu et al., 1997). The reference frame allows the individual to perceive and analyze its spatial orientation and objects to organize postural-motor activities (Le Goïc, 2013). The variables that serve as a reference to balance control and space oriented actions are self-centered, allocentric or geocentric nature (Paillard, 1971).
The egocentric spatial reference is centered in our body, based on objects and people’s location in relation to our body. The knowledge of our own space, i.e., the one occupied by our body, serves as a reference for the rest of our surrounding space. This self-centered reference in relation to space is discriminated by the left or right location of an object or person.
When we set a turn towards one side or another, we decompose space with reference to us, accepting ourselves as an axis from which space expands. Several authors suggest the use of multiple egocentric references based on different body parts like head, trunk, or limbs used for different tasks.
The exocentric or allocentric spatial reference refers to the external reference input to our body, being another form of representing positions in space that consist of relating objects and people between ourselves or to an external body reference. This reference is discriminated in relation to the proximity of the current object or established person, and the object or person to be established. This visual reference pattern refers to vertical and horizontal lines available in the environment provided by trees, lift towers, constructions, etc.
The geocentric spatial reference is about our body movements in relation to gravity directed towards the center of the earth and the reaction forces of the base of support (our feet). Terrestrial gravity constitutes an external body reference which is very important for us since being constant and omnipresent, sets a fundamental element for the constitution and maintenance of the relationship with our surroundings, i.e., something invariably of the terrestrial space. It sets an external reference in which our posture and movements are represented in relation to a gravitational referential, influencing body perception in relation to space.
The topographic spatial references are topographic marks or terrain relief as slopes, elevations, depressions, etc. considered by us when deciding trajectories. Detecting topographic references decreases motion uncertainty in good visibility conditions, but increases it in poor visibility due to low or inexistent reference detection.
The spatiality of position and spatiality of situation
If we admit that our body occupies a space and that is situated in it, then we can include the spatiality of position, which is the location of our body in space while recognizing postures and movements; and the spatiality of situation, referring to the participation of our body in actions as a dynamic body schema attribute, installing relationships with objects and other nearby people.
Initially, when we were beginners, we developed our actions in a space in which the limits were imposed by our technical limitation, by slope inclination, traffic or snow conditions, and all of this constrained us to evolve in a limited space. Through various experiences we constituted our own space, setting references that we took into account as our body, distances, terrain contour, objects, etc. As we became familiar with the surroundings, vision facilitated the perception of a wider space of action.
We learned to occupya skiing space and situatein it because of our motions, establishing relations with objects and, above all, with the fall line. At the same time, we established the basic elements for temporal organization of our motions, as the duration and continuity of the descents. Also, we took conscience of time in the simultaneity and succession of movements.
In our first attempts, we limited our visual field and were concerned mainly with our motor possibilities. We progressed in a restricted and non-coordinated space, which we appropriated it gradually through the acquisition of motion control through the use of sensations in a period known as sensorimotor.
While incorporating more technical elements, we expanded our skiing displacements, spatially appropriating other areas of the ski resort in what is called a functional space. In certain situations, and because of psychological or technical reasons, instead of experiencing space by ourselves, we may have the propensity to be structured in a restricted space, limiting our own functional space.
Spatial disorientation
Spatial disorientation occurs when we misperceive posture, movements, motion, skis setting or ourselves in relation to references provided by ground surface or by gravity. This commonly happens on days with thick fog (white out) or flat light conditions, in which we do not accurately perceive ground surface irregularities neither its inclination.
These weather conditions may cause a temporary disability to properly determine our actions and motions, as well as our condition related to the ground, even being experienced skiers. In this context, disorientation is due to optical sources deterioration (ground or lamellar optic flow) where visual references are insufficient to determine, altering the vestibular system, so our brain receives inaccurate sensory information.
Spatial disorientation is classified into three types: first, disorientation occurs when we are not conscious of our wrong perception, then we acknowledge disorientation and can fix it decreasing speed or braking, and finally, we experience such a disturbing sensation that prevents us from recovering, resulting in a fall.
According to these considerations, you can apply the following recommendations in your own skiing:
- When you set a turn towards one side or another, you decompose space with reference to you, accepting yourself as an axis from which space expands.
- Recognize that terrestrial gravity constitutes an external body reference which is very important in your relationship with your surroundings.
- Learn to occupy a skiing space and situate in it with your motions, establishing a strong relation with the fall line.
- Setting vertical and horizontal references provided by trees, lift towers, constructions, or other people will contribute to your spatial orientation.
