Assessment of biomechanical behavior of human musculoskeletal structure is essential to recognize bone diseases and to design proper medical devices.  The skeleton system basically adapts to mechanical loadings. Thus, monitoring the bone deformation under load is of great importance to attain better analysis and interpretation.  In recent years, Fiber Bragg Grating sensing devices have been developed and used to monitor strain and temperature of skeleton system.  In this work a Fiber Bragg Grating sensor is designed holding a 1.54 pmµε-1 axial strain sensitivity which is almost 30% higher than the one achieved so far.  The improvement in sensitivity is achieved by adjusting single-mode optical fiber parameters of the structure.