hello and welcome to this exam question video we're looking at 16.3 today on this aqa gcc paper
and it's asking us to define rotation now before we go into rotation and its definition
and use in sport i quickly want to clarify the difference between rotation and circumduction
because they're quite easy to get round the wrong way and if you describe one
opposed to the other in either situation then it might be an easy two marks that you're missing out
on so to start with what is rotation well it's to do with the axes now an axis is an imaginary line
or an imaginary pole around which our body is able to rotate much like a wheel turns on the axes that
runs through it perpendicular to the direction of the wheel so the wheel is standing upright
then obviously the perpendicular axis that runs through it would be the axle of the car axle axis
similarly in gymnastics which we could actually use here in a sporty example the axes would be
the bar and the gymnast who was holding on to it with their hands is rotating around
that axis perpendicular to it so how do we define rotation it's a circular movement around an axis
now this could be the whole body such as in gymnastics on the bar or doing a somersault or
a backflip or a cartwheel if we were to turn the axis that goes through the front and out the back
of the performer the cartwheel is then turning in that circular motion around that imaginary axis
the other way that we can define rotation is where both ends of the limb are rotating
around the axis that runs through it so if for example you were to stand with your hands
straight down by your side and your palms facing forward in anatomical position and you were to
rotate your whole arm with your elbow locked out your thumb would turn from pointing outwards to
pointing inwards this would be rotation because the whole limb is rotating around that axis that
runs through the limb at the same rate and speed circumduction on the other hand is when one end
or one point of the limb stays fixed and then the other end moves in a circular motion so we
end up with a shape that if you were to trace the movement looks like a circle based pyramid
or a cone shape where the point at the top was the fixed part of the limb i.e the shoulder joint and
the circle base of that cone was drawn out by the hand as it circumducted around so if you were to
example in backstroke in swimming if you were to complete a backstroke by moving that arm around
in a backward circle and you didn't turn your hand so you kept your palm facing the same way
then that would be circumduction but you could use that same example in this definition example for
rotation if in backstroke as the performer reaches for the next part of the water they are rotating
their hand so if it's sticking out like this rotation is turning on itself the whole limb from
top to bottom rotates along the same axis circumduction is when the limb stays fixed
but it actually makes a circle at the end of the bone okay now rotation is on that single
axis circumduction on the other hand is actually moving in all three different planes it's moving
across different axes through different planes in order to actually generate that movement so
it's a combination of flexion extension abduction adduction so how would you define rotation it's a
circular movement of a limb or body around an axis when would we see that in sport we would
see in gymnastics during a somersault or a gymnast on the beams going all the way around or it could
be in cricket or swimming when the whole of the arm turns on itself for example in a spin bowl
in the cricket or in football it could be when a person completes a side foot trap and they
go from standing with their feet facing forwards and they turn their toes to point outwards so that
the inside face of the foot is there to control the ball and that's that the difference between
rotation and circumduction in sport hope it helped and i'll see you again in the next one bye for now