Center and Line of Gravity

Feedback cues:

• Where do you feet start and finish after the movement.

Figure 5: Highlights the movement outside the line and center of gravity required. Adapted from http://getbetterfaster.tv/wp-content/uploads/2014/10/RennerThrowSequence.png

Robert Heppe’s own research and literature review highlights the importance of centre and line of gravity within the American Football throw. Typically in a sporting context athletes aim to plant their feet within shoulder width to widen their base of support, doing this will place the athletes centre of gravity within the base of support and keep the centre of mass and centre of gravity aligned, increasing stability. (Blazevich, 2013, p. 65). This stable position also allows for the greatest range of movement patterns an athlete has a t their disposal, but the specific rotational action of the skill changes the relevance of these principles.  Heppe argues that up to 49 percent of the balls total velocity is generated through stride and rotation of the body at the start of the throwing motion (Heppe, 1992, p. 4) Through testing of right handed athletes Heppe states that an effective athlete actually places their stride foot slightly to the left of the midline, putting the centre and line of gravity slightly to the non-dominant side. He argues by putting the stride and the line of gravity towards one side this allows complete rotation towards the target thus maximum angular velocity as well as better accuracy because of the superior vision afforded by the front on position.

It is important to note that the step and lean needs to be minimal to avoid decreasing the effective ness of the skill. If the athlete is too bent over the angle of release will be effected and if the athlete is leaning too far to one side stability and accuracy may be effected.