Physical factors influencing the throwing action in netball and cricket players
Thesis (M Sport Sc (Sport Science))--University of Stellenbosch, 2007.
The ability to execute a powerful throw is an essential skill for netball and cricket players. Numerous accurate, powerful throws are being made during the course of a match. It is thus necessary to focus on the development of excellent technique, as well as the development of the physical aspects that might contribute to the effectiveness and efficiency of the throwing action. The aim of the study was to determine which specific physical factors play a significant role in the distance that netball and cricket players can throw a ball. The distance of the thrown ball was also seen as an indirect measure of the power with which the throw was executed, with a greater distance implying more power. A group of volunteer subjects was drawn from the local netball and cricket clubs from the Stellenbosch area. Thirty nine injury-free, club level subjects participated in the study, of whom twelve (n=12) were male and twenty four (n=24) were female. Various physical factors were selected that give an indication of its contribution to a powerful throw for distance. Range of motion assessments involved the range of the shoulder joint, as well as the elbow joint, wrist joint and the back. The strength of the internal rotators was compared to the strength of the external rotators in the shoulder joint. Core stability was assessed by doing two different tests, with one involving shoulder stability as well. The relationship between upper-limb length and the throwing distance was assessed. Various anthropometric measurements were done, including height, weight, skinfolds, and the “wing span”. Throwing for distance was measured while the subjects remained seated on a chair. This throwing position was chosen in an attempt to eliminate the contribution of the kinetic chain that generates momentum in the lower extremities which get transferred to the upper extremities. It was thus an attempt to only focus on the involvement of the upper extremities. This seated throwing position is also often used as a test for throwing ability in athletes. Throwing for distance was also done with the subject strapped onto the chair to exclude the involvement of the core in the transfer or generation of energy. Results from this study showed that there were very few physical factors that had significant correlations in both groups. In the cricket players, factors from the isokinetic testing played a significant roll, but not in the netball players. There was a significant correlation which was positive with the average peak torque concentric/concentric 180 degrees/second with external rotation seated on the chair (r=0.46; p=0.03). There is also a tendency towards a significant correlation when the subject was seated in average peak torque concentric/concentric at 90 degrees/second both with internal (r=0.52; p=0.06) and external rotation (r=0.62; p=0.05). The peak torque concentric/concentric at 90 degrees/second during external rotation (r=0.61; p=0.06) and the peak torque concentric/concentric at 90 degrees/second during internal rotation (r=0.49; p=0.06). Both tended to a correlation but were not significant. There was found to be a few positive and statistical significant factors the average power concentric/concentric contractions at 90 degrees/second during external rotation when seated on the chair (r=0.64 and p=0.03) and average power concentric/concentric contractions at 180 degrees/second during external rotation when seated on chair (r=0.58; p=0.04) as well as strapped in on chair (r=0.06; p=0.03). It cannot be concluded there are any specific physical factors that would influence the distance thrown in both the netball and the cricket players. It can thus be assumed that a number of other factors might play a more important role in the execution of a powerful throw for distance, such as the involvement of the total well-coordinated kinetic chain, and the throwing techniques.