The study is planned to be conducted in 2025. The methods used in the study are non-invasive methods. The study groups will perform 1 to 3 static stretching sessions per week. The number of series per session will be from 1 to 3. The static stretching time of the back band in the series will be from 20 s to 60 s. The total stretching time per week will be from 45 s to 135 s. The break between series will be 45 s, and the duration of the intervention will be from 6 to 8 weeks. During stretching, the subject maintains a maximum bend with straight knee joints for a specified time. Before starting the study, participants will undergo a toe-to-floor test to assess the flexibility of the back band. The test will be repeated after the intervention. The aim of the study is to determine the minimum effective dose of static stretching. Currently, anecdotal evidence suggests that this dose is 90 seconds of static stretching per week.

The study does not involve any likelihood of harm to study participants as a result of participating in the study.

Inclusion Criteria:

• Age over 18 years,
• No lower limb injuries, no spinal injuries and no craniocerebral injuries in the last 6 months,
• No lower limb surgeries, no spinal surgeries and no central nervous system surgeries in the last 6 months,

Exclusion Criteria:

• Age under 18 years
• Injuries to the lower limbs, spine or craniocerebral injuries within the last 6 months,
• Surgical procedures to the lower limbs, spine or surgical procedures to the central nervous system within the last 6 months,