<p><b>Introduction: </b>The objective of the study was to assess the flexibility of the hamstring muscles and their relationship with the position of the spine, shoulder and pelvic girdles in individual planes in boys training football. <p><b>Material and methods: </b>The study included 28 boys aged 10-14, training football 3 times a week for at least 2 years. The subjects were divided into two groups: correct bilateral flexibility of the hamstring muscles, bilateral shortening of the hamstring muscles. Body height and weight were measured and BMI was calculated. The three-dimensional position of the trunk was examined using the Zebris pointer ultrasound system. The passive straightleg- raising test was used to assess the flexibility of the hamstring muscles. <p><b>Results: </b>32% of people were diagnosed with the correct length of both hamstring muscles, 57% had shortened muscles in both limbs. Mean values determining the depth of thoracic kyphosis indicated its deepening in each of the groups, however, lower values were recorded in boys with reduced flexibility of the hamstring muscle mass. This group was also characterised by a better balance of the trunk in the sagittal plane. The average depth of lumbar lordosis in both groups was within the normal range. In the frontal plane, in both groups of footballers there was a tendency to lift the left shoulder (more frequent in the group with normal flexibility), the pelvis on the left side and shift the trunk to the right. <p><b>Conclusion: </b>Shortening of the hamstring muscles is common in boys who train football, but no evidence of a relationship between the limited flexibility of these muscles and the position of the trunk was found.
Reconstruction of a scoliotic spine using a three-dimensional medical ultrasound system
