The ergonomics is one of the key factors in any service sector where the workers are involved in physical work. The physical strength of an individual is dependent on the human artefacts which may help the system to recruit the suitable person to right place. The present study comprises the body flexibility (Bf) of the servicemen associated to Indian railway. Four inputs i.e. age, height, weight, and waist of all recruited participants are measured and conduct the sit and reach test (S-R test) for the Bf. The statistical analysis is performed for investigating the significance of the inputs on the Bf. Statistically, the inputs Ag (P=0.002), Wg, (P=0.030), and Wa-g (P=0.001) are individually significant whereas the interactional relation of Hg with Ag (P=0.008) and Hg with Wa-g (P≤0.001) is reported. The Bf of Tall Hg is grown up gradually with Ag but it was 20.47% lesser than the maximum Bf. Simultaneously, with the increase in Wa-g of all Hg, the degradation in the Bf is reported.