Influence of invertor and evertor muscle fatigue on functional jump tests and postural control: A prospective cross-sectional study

Proprioceptive neuromuscular facilitation warm-ups: a key to improved isokinetic performance

This study examined the immediate effects of proprioceptive neuromuscular facilitation warm-ups on isokinetic strength, endurance, and body balance in 50 football players. Data collection spanned four sessions, each separated by full rest. The isokinetic strength of the hip, knee, and ankle flexion and extension was measured using a dynamometer at 60°/s, 180°/s, and 240°/s. Endurance was assessed at 240°/s through 25 repetitions, analyzing peak torque changes. On the first day, participants performed general warm-ups followed by balance and strength tests. Subsequent sessions repeated these tests with additional measurements. Results showed that proprioceptive neuromuscular facilitation warm-ups significantly improved the static and dynamic balance compared to other methods. Peak torque measurements at all speeds also highlighted the superior effectiveness of proprioceptive neuromuscular facilitation warm-ups. Additionally, this warm-up approach provided greater acute enhancement in knee joint isokinetic endurance. In conclusion, proprioceptive neuromuscular facilitation warm-ups increased the isokinetic strength, endurance, and balance in football players. Incorporating proprioceptive neuromuscular facilitation warm-ups into football training especially for lower body preparation is recommended. Combining them with active warm-ups may further boost acute performance.

The bone mineral density and isokinetic knee strength in amputee soccer players

OBJECTIVE

The aim of this study was to examine the isokinetic knee strength, H/Q ratio (%), and bone mineral density values between amputees (n=14; amputee soccer players) and healthy football players (n=14; non-amputee soccer players).

METHODS

A total of 28 amputee soccer players and non-amputee soccer players participated in the study. An isokinetic dynamometer was used to determine the knee flexion/extension forces of the dominant legs of the athletes at 60, 180, and 240°/s. Bone mineral density scans were performed using dual-energy X-ray absorptiometry.

RESULTS

H/Q ratio and 60º/s flexion and 180 and 240º/s flexion/extension strength (p<0.05) were found to be high (180º/s, p=0.03; 240º/s, p=0.048) in the non-amputee soccer player group. Accordingly, the bone mineral density values of the lumbar vertebra, femoral neck, proximal metaphysis of the femur (p<0.01), tibia/fibula proximal metaphysis, and tibia/fibula distal metaphysis (p<0.05) were found to be high. A correlation was observed between the 60º/s knee extension strength and tibia/fibula diaphyseal bone mineral density (p=0.025; r=0.594) and tibia/fibula distal metaphysis bone mineral density (p=0.017; r=0.623) values in the amputee soccer players group. The Z-scores of the amputee soccer players and non-amputee soccer players were in the expected range according to age (>-2).

CONCLUSION

The bone mineral density, H/Q ratio, and all measured angular velocities of isokinetic strength were high in non-amputee soccer players. This finding made us think that lower extremity amputation may also be associated with losing strength. However, it was observed that the relationship between strength and bone mineral density in amputee athletes might vary according to different angular velocities. It is recommended that isokinetic strength measurement can be evaluated together with bone mineral density in athletes.

Acute effect of kinesio tape on postural control in individuals with functional ankle instability following ankle muscle fatigue

Background: Kinesio taping (KT) is one of the therapeutic interventions in sports medicine practice. The study aims to assess the acute effect of different KT methods on postural control in individuals with functional ankle instability (FAI) after ankle muscle fatigue.

Methods: Twenty-eight participants with FAI were recruited to complete maximum voluntary isometric contraction (MVIC) and proprioception of ankle using isokinetic dynamometer, dynamic postural control using Y-balance test and static postural control using a force platform after a fatigue protocol in four taping conditions: facilitatory KT (FKT), ankle balance taping (ABT), sham taping (ST) and no taping (NT).

Results: No significant difference was observed for the data MVIC and proprioception after ankle muscle fatigue amongst the four taping treatments. A significant difference in Y-Balance Test was observed amongst the four taping treatments at posterolateral direction (p < 0.001) and posteromedial direction (p < 0.001), suggesting that KT may significantly improve dynamic postural control following ankle muscle fatigue. For Center of pressure (COP) measurements, the mediolateral COP sway range of NT was significantly larger than that of FKT (p = 0.003) and ST (p < 0.001), suggesting that the placebo effect of KT was inevitable.

Conclusion: The effect of KT seems increased dynamic postural control in individuals with FAI after ankle muscle fatigue, and this effect is not strongly related to the taping methods. By preventing fatigue-related impairments of postural control, KT may help reduce the risk of injury in individuals with FAI.