PURPOSE: The purpose of this study is to verify the effect of soft tissue stiffness on joint range of motion and athletic performance in soccer players.METHODS: Fifteen adult male soccer players participated in the study. After the warm-up, calf muscle and Achilles tendon stiffness were measured. Subsequently, range of motion of the ankle joint and 30 m sprint and vertical jump were performed. Exercise performance was assessed as a field test to create an experimental environment similar to that of actual training and competition.RESULTS: Achilles tendon stiffness showed a significant correlation with the 30 m sprint and the vertical jump (<i>p</i><.05). A moderate correlation was observed between the 30 m sprint and the vertical jump(<i>p</i><.01). Soleus muscle stiffness was significantly correlated with the 30 m sprint(<i>p</i><.05). No other correlations were observed.CONCLUSIONS: Therefore, it was confirmed that Achilles tendon stiffness affects exercise performance. In a follow-up study, it was necessary to confirm the effect of the stiffness of various soft tissues on exercise performance.

PURPOSE: This study aimed to investigate the effects of circuit-type neuromuscular training (CTNT) on strength, power, and functional performance among the MZ generation.METHODS: Twenty-eight participants were assigned to either the circuit-type neuromuscular training group (CTNTG, n=14) or the control group (CG, n=14). CTNT was performed for 50 minutes a day, 2–3 times a week, for 6 weeks. The CG only performed activities of daily living during the study period. Baseline and post measures included isometric muscular strength (knee flexion, knee extension, back flexion, back extension), vertical jump, 30 m sprint, T-agility, and Y-balance tests.RESULTS: The results showed that the CTNT had a positive effect on the improvement of knee flexion (<i>p</i>=.015), knee extension (<i>p</i>=.047), back extension (<i>p</i>=.003), vertical jump (<i>p</i>=.025), T-agility (<i>p</i>=.046), posteromedial (<i>p</i>=.031), posterolateral (<i>p</i>=.022), and composite score (<i>p</i>=.032).CONCLUSIONS: These findings can be a factor that the strength, power, and functional performance of MZ generation can be sufficiently improved through the CTNT program. This suggests that CTNT is the most appropriate exercise intervention method to improve the strength, power, and functional performance of the MZ generation.

PURPOSE: This study aimed to investigate the effect of dynamic warm-up (DW), including DW and self-myofascial release (SMFR), on soft tissue stiffness and exercise performance.METHODS: Eight adult men participated in this study. The procedure was conducted twice every 2 weeks. Soft tissue stiffness measurements and exercise performance were performed as a pre-post-test. DW only and DW with SMFR were performed as an exercise intervention for the two groups, respectively.RESULTS: In the group conducted solely by DW, the stiffness of the gastrocnemius and rectus femoris muscles increased (<i>p</i><.05), and in the DW group including SMFR, the stiffness of the rectus femoris muscle (<i>p</i><.01) and biceps femoris muscle increased (<i>p</i><.05). The Achilles and patellar tendon showed no significant changes in either group. A significant increase was observed in both the DW group and the DW group containing SMFR in the 30 m sprint (<i>p</i><.01). The vertical jump (VJ) showed no significant change in both groups.CONCLUSIONS: Therefore, DW, including DW with SMFR, increased muscle stiffness, specifically through a 30-m sprint. In a followup study, it is considered necessary to investigate the effect of the VJ through the development of a DW program that changes the stiffness of tendons.

PURPOSE: This study aimed to analyze the acute effect of active tibial rotation exercise on tibial torsion angle, ankle range of motion, and neuromuscular control.METHODS: This study was based on AB/BA Cross-over design, and participants were divided into two conditions (core-tex tibial and manual tibial rotation exercises). Before and after the exercise intervention, tibial torsion angle, non-weight bearing ankle range of motion, weight-bearing ankle range of motion and dynamic balance test, and Shark skill test were conducted.RESULTS: An interaction effect was found in the left non-weight-bearing ankle range of motion and the right posterolateral (PL) of theY Balance Test. In addition, there were significant differences between periods in left tibial torsion angle, non-weight-bearing anklerange of motion, bilateral weight-bearing ankle range of motion, bilateral AN, bilateral posteromedial, right PL, bilateral compositescore, and bilateral Shark skill test.CONCLUSIONS: Tibial rotation exercise is considered valuable as sports injury prevention training due to its effectiveness for lowerextremities functionally and structurally regardless of tibial rotation exercise type.