Stephen Seiler FASCM and Atle Sæterbakken
A unique core stability training program improves throwing velocity in female high school athletes. Medicine and Science in Sports and Exercise 40(5, supplement), s25, 2008.

28 female handballplayers were divided into two groups. One group trained S-E-T (Redcord) was compared to a control group. Before and after the training intervention throwing velocity with a 600g handball was measured with photo cell array. Testing of one legged balance and push-up in unstable slings was also measured. The S-E-T (Redcord) group performed 6 exercises in closed kinetic chain twice a week for 7 weeks. Averaged throwing velocity increased significantly in the S-E-T (Redcord) group (4,9%) compared to no change in the control group. Functional strength measured as push-up in unstable slings also increased significantly in the S-E-T (Redcord) group. One legged balance was not significantly improved after the intervention in either group. The study conclude that core stability training performed in closed kinetic chain can significantly increase throwing velocity in handballplayers. Only the abstract is so far published.

Purpose
To determine the impact of a Sling Exercise Training (SET) core stability program on maximal throwing velocity in high school age female team handball players.

Methods
28 female team handball players (16.6±0.3 yrs, 63±6 kg, 169±7 cm) were initially divided into an SET training group (n= 15) and a control group that performed their normal training (n=13). After loss to post testing, 14 SET trained (SET) and 9 control athletes (CON) were compared. Before and after the training period, throwing velocity (600 g handball, average of three best throws) was determined from a penalty shot position using a photo cell array, along with one legged balance, unstable push-up strength, and two weak link tests. The SET group performed 6 closed kinetic chain, unstable exercises, 2.wk-1 for 7 weeks.

Results
Averaged throwing velocity increased 4.9% from 17.9±1.8 to 18.8±1.5 m.s-1 in SET (p<0.01), but was unchanged in CON 17.2±1.4 to 17.0±1.3 m.s-1 (p>0.05). Functional strength measured as modified pushups to failure with arms in slings increased in SET from 21±5 to 37±10 (p<0.001) vs from 11±7 to 16±9 in CON. One legged balance was not significantly improved after the intervention in either group.

Conclusion
Core stability for an athlete may be defined as the ability of the hips and trunk to resist rotational torque. A strong and stable core region may be an important precondition for generating high rotational velocity in multi-segmental movements. The results of this study suggest that core stability training using closed kinetic chain exercises performed in unstable slings can significantly improve maximal throwing velocity.