|dc.description.abstract||During a javelin throw, research suggests that 70% of the release speed is provided during
the point of foot contact with the ground at the start of the block and the point of release,
yet this only lasts one tenth of a second. This study was designed to analyse this short
period of time; more specifically, whether the rate of force development exerted into the
ground during the block directly linked to speed of release? Three elite throwers were used
as participants and were studied over six trials each. CODA motion analysis system (200
Hz), a force plate (1000 Hz) and a video camera (50 Hz) were used to conduct a 3D
analyses of the participants’ block.
No definitive correlation was found between rate of force development and the speed of
release (correlations of 0.39, -0.48 and 0.44 for participants one, two and three
respectively) however after including other factors a strong relationship was found
between the two variables. To enhance speed of release the amount of time the force is
applied on the object and the magnitude of this force needs to be optimised. An effective
block increased the time between the point of foot contact and release (the time the force
was acting on the object), as well as increased the magnitude of the force by increasing
the separation angles between joints, thus increasing the torque; however movements
became slow (reducing the force) if the time continued to increase. An effective block also
aided momentum transfer into the hip strike, further increasing the magnitude of the force.
The findings suggested that an effective block is vital in optimising the speed of release.
This entails achieving the highest rate of force development possible during the block
(found to be highly dependent on an individual’s optimal run up speed)||en_US