Thoracic Kyphosis and Its Relationship with Hamstring Muscles Flexibility in 12-17 Aged Iranian Students

The purpose of the present study was to investigate thoracic kyphosis and its relationship with hamstring muscles flexibility in Iranian students.

A total of 13’712 students (6968 girls and 6764 boys), aged 12-17, selected randomly from schools of seven geographical regions of Iran, participated in the present study. Thoracic curvature was measured using the flexicurve method and hamstring muscle flexibility was measured using sit and reach test. Making use of descriptive statistics, means and standard deviations were calculated for all the variables. Non-parametric spearman correlation coefficient was used to determine the relationship between sagittal spinal thoracic curvature and the hamstring muscles flexibility.

The results showed that the mean values of thoracic kyphosis was 32.85±11.93 degrees in female students and 36.89±10.61 degrees in male students and the mean values of hamstring muscle flexibility was 33.38±9.62 (cm) in female students and 30.01±10.41 (cm) in male students. Findings also demonstrated that there was no significant relationship between hamstring flexibility and thoracic kyphosis among Iranian male and female students (r = -0.05).  

Based on the findings of the current study, a broad range of thoracic kyphosis and hamstring muscles flexibility was identified according to different age groups and genders. Additionally, no strong relationship has been shown between thoracic kyphosis and hamstring muscles flexibility in Iranian students. These findings can be used as a comprehensive basis for teachers, trainers, and any related parties to the health and education of the students, as well as future studies in this area.