Assessment of the mechanical properties of muscles in adults in relation to the position of the hip bones – preliminary study

Asymmetry in the form of Lumbo–Pelvic–Hip Complex (LPHC) is a common phenomenon in the adult population. No consensus has been reached in the literature reviewed, as far as the impact of posture defects upon the occurrence of muscle imbalance, faster development of degenerative changes in the joints and pain intensity are concerned. Thus, it needs to be defined clearly in which cases the diagnosis of (LPHC) asymmetry in adults provides the basis for starting rehabilitation. The aim of the study was to determine whether in the case of this asymmetry changes in the viscoelastic and biomechanical properties of LPHC muscles occur. Methods: The study comprised 64 adults, divided into two groups on the basis of physical examination: pelvic symmetrical (n = 34), and pelvic asymmetrical (n = 30). Myotonometric measurements of output parameters: tension, stiffness and elasticity were carried out to assess the mechanical properties of LPHC muscles in both groups. Results: Tension, stiffness and elasticity of the examined muscles, namely: abdominal muscles, rectus femoris muscle, erector muscle of the spine and biceps femoris muscle were measured. The pelvic symmetrical group, and the pelvic asymmetrical group did not differ with statistical significance as regards the comparison between the left and right sides of the body of the subjects. Also, no statistically significant differences in the occurrence of pain were found between the study groups. Conclusions: Our findings have important clinical implications. The asymmetry of LPHC, commonly diagnosed in adults during functional examination for the purpose of physiotherapy, should not provide the basis for starting rehabilitation, in the absence of pain.