The influence of static stretching of specific lower limb muscle groups on the jump height parameter of volleyball players aged 16-17: a pilot study

Introduction
The jump is one of the most important parameters in volleyball. Often, warmup exercise strategies are based on static stretching. The aim of the study is to show whether the static stretching of muscles of the lower limbs influences the jump parameter of volleyball players.

Material and methods
The study included 25 players (16-17 years) from the club AKS Resovia Rzeszów. The study consisted of two measurements (M1 and M2) with intervention conducted between them. The vertical jump and heel to buttock tests were performed. Quadriceps femoris, iliopsoas and gastrocnemius were subjected to static stretching.

Results
Statistically significant differences in the heel-buttock test between the M1 and M2 for both right and left lower limbs were found. The average distance between the anthropometric points in M1 for the left lower limb was 14.54±6.16 cm. This tendency was similar to the right lower limb. After the intervention in M2, the average distance was 11±6.06 cm. A significant reduction of the value of the vertical jump after the intervention has been noted. The average value of the jump before the intervention was 325.64±10.15 cm. In M2 the mean value was 324.24±9.81 cm. The difference between M1 and M2 was statistically significant.

Conclusions
It has been found that in the study group static stretching had negative influence on the jump parameters directly after performing it. A positive effect of static stretching on increasing the range of mobility of the knee joint was noted.