Mena Bejarano B1, Rojas González LR1, Quiceno Noguera C1, Mancera Soto EM1
1Universidad Nacional de Colombia, Movimiento Corporal Humano, Bogotá, Colombia
Background: Based on the benefits of eccentric exercises, the physical demand on soccer players, the strength deficiency in lower limbs and its relationship with injure incidence worldwide, the importance of establishing new intervention programs is determined. This research allows recording changes in the strength of knee flexors and its relationship with the dynamic knee stability.
Purpose: To determine the effectiveness of the Nordic modified training protocol on the dynamic knee stability in soccer players.
Methods: Randomized Controlled Trial. The assessment was conducted with a Cybex Norm dynamometer before and at the end of the intervention protocols.The isokinetic conventional CON/CON bilateral assessment was defined for flexion/extension knee muscles at 60º/s, 180º/s and 300º/s speed. 22 soccer players participed. The participants were randomly to control group (CG) and experimental group (EG). EG developed a modified Nordic (MN) protocol for hamstring muscles and CG developed a convencional Nordic (N) protocol during 10 weeks.. A statistical analysis was performed using a factorial ANOVA model with three analysis models that allows determining the maximum strength peak (MSP), the bilateral index (BI) and unilateral index (UI) of knee flexion/extension muscles at the different speeds.
Results: EG showed increase in MSP at the end of the protocol at the three speeds. At 60 °/seg, the MSP of left side knee flexors increase 7 N (p 0,014). There were significant differences in the maximal strength of right-side knee flexors at 180º/s between EG (65,8N) and CG (51,2N) (p 0,050). At 300º/s , the 2:3 flexion/extension ratio is conserved in the right lower limb in both groups. (p 0.01). There is no significant difference in the unilateral knee flexion/extension index.
Conclusion(s): SPM increased in knee flexors after applying the protocols N and NM. The NM protocol significantly contributes to the maximum strength increase in knee flexion muscles. On the other hand NM favors the knee flexion/extension balance and allows developing strength in the weaker muscle groups by contributing to the bilateral balance of the player. These modifications improve the player's functional performance during the match and the sporting gesture. Additionally ,NM could prevent sports injuries and enhance dynamic bilateral knee stability.
Implications: The implementation of NM has a positive effect on the prevention of sports injuries in acyclic sports that involve changes in speed and direction, accelerations, jumps, among others. They also optimize physical performance and promote joint stability and proprioception
Keywords: Knee, soccer, Training
Funding acknowledgements: This study was funding by Coldeportes Colombia
Purpose: To determine the effectiveness of the Nordic modified training protocol on the dynamic knee stability in soccer players.
Methods: Randomized Controlled Trial. The assessment was conducted with a Cybex Norm dynamometer before and at the end of the intervention protocols.The isokinetic conventional CON/CON bilateral assessment was defined for flexion/extension knee muscles at 60º/s, 180º/s and 300º/s speed. 22 soccer players participed. The participants were randomly to control group (CG) and experimental group (EG). EG developed a modified Nordic (MN) protocol for hamstring muscles and CG developed a convencional Nordic (N) protocol during 10 weeks.. A statistical analysis was performed using a factorial ANOVA model with three analysis models that allows determining the maximum strength peak (MSP), the bilateral index (BI) and unilateral index (UI) of knee flexion/extension muscles at the different speeds.
Results: EG showed increase in MSP at the end of the protocol at the three speeds. At 60 °/seg, the MSP of left side knee flexors increase 7 N (p 0,014). There were significant differences in the maximal strength of right-side knee flexors at 180º/s between EG (65,8N) and CG (51,2N) (p 0,050). At 300º/s , the 2:3 flexion/extension ratio is conserved in the right lower limb in both groups. (p 0.01). There is no significant difference in the unilateral knee flexion/extension index.
Conclusion(s): SPM increased in knee flexors after applying the protocols N and NM. The NM protocol significantly contributes to the maximum strength increase in knee flexion muscles. On the other hand NM favors the knee flexion/extension balance and allows developing strength in the weaker muscle groups by contributing to the bilateral balance of the player. These modifications improve the player's functional performance during the match and the sporting gesture. Additionally ,NM could prevent sports injuries and enhance dynamic bilateral knee stability.
Implications: The implementation of NM has a positive effect on the prevention of sports injuries in acyclic sports that involve changes in speed and direction, accelerations, jumps, among others. They also optimize physical performance and promote joint stability and proprioception
Keywords: Knee, soccer, Training
Funding acknowledgements: This study was funding by Coldeportes Colombia
Topic: Sport & sports injuries; Musculoskeletal: lower limb
Ethics approval required: Yes
Institution: Universidad Nacional de Colombia
Ethics committee: Medicine Faculty
Ethics number: Register 003-016-15
All authors, affiliations and abstracts have been published as submitted.
