In figure skating is immediately obvious that the 'balance is the primary determinant of the performance of this sport. The 'balance of the skater is manifested in all phases of' learning and 'training: it is at first to maintain a stable position despite a travel speed, changing direction and pace, spins and shapes made to land. For this phase the reference points visual and kinaesthetic are very important, the body must also be perfectly balanced and stable way to prepare an optimal stage of momentum, the only guarantee for the success of the jump.
To maintain or restore the 'balance, the skater uses several factors: the rate of movement, centrifugal force, bending the knee, the movement and position of the arms and free leg, the tension of the body, rhythm. Each figure is broken down into different sequences and repeated until it is mastered perfectly.
The static equilibrium
Maintain or restore the 'balance in place in different conditions. In this case play a key role in the visual receptors and foot, the first gives information about the geometry of the area 's support of the body to the ground and the characteristic reaction force which is exercised. The damage points on second 'vertical axis. At first glance, the 'balance without moving the body seems to be the easiest to find or to restore, but in reality the variations are endless. Just think of the standing su una superficie stabile e di grandi dimensioni senza influssi esterni, all’ equilibrio su una sola gamba, ad occhi chiusi ,su una panca rovesciata mentre si gioca con una pallina, o infine su una superficie in movimento o instabile (esempio: atterraggio di un salto).
Equilibrio dinamico
Mantenere o ristabilire l’ equilibrio con un movimento traslatorio del corpo. In questo caso sono i recettori dell’ orecchio interno a svolgere un ruolo di primaria importanza, rilevando le accelerazioni sul piano orizzontale e verticale. Questa forma di equilibrio comprende movimenti semplici, come camminare o salire le scale. Il piede mantiene il contatto con la superficie d’ appoggio diretta (terreno, acqua, asse, ponte, corda) o indiretta (bicicletta, pattini, sci). Come per quello statico, il compito si fa più difficile man mano che la superficie d’ appoggio diminuisce, cambia, diventa instabile e contemporaneamente aumentano il numero di informazioni cinestetiche e tattili necessarie. Si deve anche tenere conto di spostamenti effettuati in varie direzioni a velocità variabile.
Equilibrio nelle rotazioni
Mantenere o ristabilire l’ equilibrio durante e dopo le rotazioni intorno ai tre assi del body (transverse, longitudinal, sagittal). The vestibulo ocular allows, in this case, to stabilize gaze during head movement and keep it that way a reference point. The receptors of the 'inner ear record and transmit to the central nervous system the angular accelerations of the head, allowing the reactions to initiate appropriate muscle to straighten the body. Variations and combinations are endless in this area: turn on the same ground, with eyes closed (longitudinal axis), different chain wheels (sagittal axis) flipped back and forth, back flips (lateral axis)
balance in flight
Maintain or restore the 'balance in the air phase. The flight phase may vary in different sports from a few tenths of a second a few seconds. L 'absence of a stable further complicates the achievement of the motor task. Kinesthetic receptors ongoing information on the position of the engines of the body segments and muscle tension, which is essential for keeping the body itself. This form of balance is almost always combined with the previous one. The jump in the most acrobatic, are accompanied in fact from spin. The 'zero gravity complicates the process of balance because of lack of references to vertical and the weight of the body in such cases are the visual receptors to assume the main function.
These four forms of equilibrium described above never occur alone but are always combined together in the 'context of a movement, sensory information at all times cooperate to manage the imbalance. Their hierarchy is not limited to depending on the motor task, but also of 'age, experience, physical and mental state of the subject at the time of' activities.
0 comments:
Post a Comment