Prevalence of hamstring tightness and associated factors among sewing machine operators

Background: Hamstring is a key component of flexibility in the human body and it is more prone to get tightened. Inability to achieve greater than 160 degrees of knee extension when the hip is flexed to 90 degrees is considered as hamstring tightness. Objectives: This study aims to find the prevalence of hamstring tightness among sewing machine operators and to assess the association of hamstring tightness with prolonged sitting, body mass index, physical activity level and gender. Method: A descriptive cross sectional study was carried out among 169 sewing machine operators aged between 18-60 years of a selected garment factory. Passive knee extension (PKE) test was used to measure the hamstring tightness among sewing machine operators. A validated interviewer administered questionnaire was used to determine the physical activity level among the participants. Results: Prevalence of hamstring tightness among sewing machine operators is 83.4% (n=141) and it is higher in males (91.8%) than females (78.7%). There was a significant association between prolonged sitting and hamstring tightness in the dominant limb (p=0.02, chi square = 7.79). Significant associations were not found between hamstring tightness with the BMI level (p=0.46, r=-0.05) and physical activity (p=0.41, r=-0.06). Conclusion: Majority of the sewing machine operators have hamstring tightness. Prolonged sitting is a contributory factor in hamstring muscle tightness.