Background Anterior cruciate ligament injury prevention programs may be received more warmly if a program is presented with the emphasis on performance improvement.
Objective To examine the effect of an original exercise program (GLAB program) using ReaLine BalanceShoes (RBS) on measures of athletic performance in young volleyball players.
Design A single-blinded randomised controlled trial.
Setting Three volleyball teams.
Participants 57 volleyball players aged 16–22 with no current history of lower extremity injuries; 29 players (17 females, 12 males) allocated to the intervention group; 28 players (17 females, 11 males) to the control group.
Interventions The intervention group used RBS, a shoe-type training device aimed for correcting dynamic knee abduction. The sole of the RBS remains horizontally balanced only if the knee-over-the-toe position is maintained. A 4-staged progressive exercise program was developed, including slow closed-chain strengthening, joint realignment (restoring screw-home movement), balancing (biofeedback), feed-forward (landing) and plyometric (jumping) components. The control group performed same exercises without wearing RBS. One session taking 15 min was executed 3 days a week for 4 weeks.
Main outcome measurements Vertical jump height (VJH) and single-leg hop distance (SLHD).
Results Average increase in VJH and SLHD (right and left) of the intervention group were 4.5 ± 5.3 cm, 9.0 ± 9.9 cm, and 10.2 ± 11.9 cm, respectively; corresponding values in the control group were 0.9 ± 3.7 cm, 5.7 ± 8.8 cm, 2.6 ± 12.8 cm. Between-group comparisons indicated the GLAB program resulted in greater improvements in VJH and left SLHD as compared with the control program (p=0.004, 0.02, respectively).
Conclusion The GLAB program using the RBS enhanced athletic performance. A noteworthy is a VJH increase by 4.5 cm only in 4 weeks. This finding would likely be helpful in promoting injury prevention program to athlete at large.