Graphics Reference
In-Depth Information
FIG 5.61
Young girl jogging
sequence.
and make for more efficient motion, but they do not directly
enable
the
action. In a running action the backward and forward swinging action of the
arms, synchronized with the movement of the legs, makes a considerable
contribution to the effectiveness of the action that is particularly noticeable
at very high speeds. There is clear evidence of the contrary action of arms
and legs in all running actions, regardless of speed; when the right leg is
in the forward position, the right arm is in the backward position; likewise,
when the left leg is in the forward position, the left arm is in the backward
position. These arm movements become less extreme and not such a great
contributing factor at lower speeds, as evidenced by the different actions of a
sprinter and a marathon runner.
The movement of the arms during a jogging action is often even more
subdued than the action in a sustained run at moderate speeds, such as that
of a long distance runner. During a jogging action, arms are generally held
quite rigidly, bent at the elbow with the forearms held at the horizontal. The
swinging action of the arms tends to rise far less, the forearms being brought
across and in front of the torso and the hand seldom rising to a much higher
level than halfway up the chest. By comparison, with the action of a sprinter
off the blocks, the arms are often raised so high that the hand is brought up to
the level of the head.
The stride in a jogging action is often much shorter than in a running action.
The legs are lifted a good deal less during the passing position than within the
run. There is a much shorter frequency of stride length in a jog than in a run.
This, coupled with the far smaller difference in height achieved during the
suspended phase, gives the waveform created by a jogging dynamic a much
