Effect of Double-density Insoles on Muscle Activity Frequency During Running and Side Cutting in Adolescent Volleyball Players

Purpose: Volleyball is a complex sport with specific muscular demands and a variety of explosive physical characteristics.The present study aimed to examine the effect of double-density insoles on the frequency of muscle activity during running and side cutting in volleyball players.Methods: This quasi-experimental study was conducted with 30 teenage boys and girls, divided into two groups of 15 participants.The electrical activity of seven lower limb muscles was recorded during six running attempts and lateral sliding attempts using a biometric 8-channel electromyography device with 2-pole surface electrodes, according to the SENIAM European protocol. Results:The results revealed that double-density insoles significantly influenced the frequency of BF muscle activity during running (P=0.045,d=0.136).Group differences significantly affected the frequency of tibialis anterior (TA) muscle activity (P=0.027,d=0.163) and vastus medialis (VM) muscle activity (P=0.006,d=0.239) during lateral sliding.Additionally, the interaction between double-density insoles and group classification significantly influenced semitendinosus (ST) muscle activity during lateral sliding (P=0.037,d=0.146), with boys showing increased ST activity but not girls. Conclusion:The use of double-density insoles at the frequency of the biceps femoris (BF) muscle can prevent anterior cruciate ligament (ACL) damage and acute muscle injuries during running.At the frequency of the ST muscle during sliding, it can be effective in preventing genu varum injury in volleyball players.