Alteration in the center of mass trajectory of patients after stroke

Abstract

Background:

The movement disorders due to stroke can alter the motion of the Center of Mass (CoM) of the body. Thus, the analysis of the CoM motion can be an alternative to diagnostic the stroke gait disturbances and has not been widely explored.

Objective:

To identify and to analyze the alterations of CoM trajectory during both of gait cycles, affected and unaffected, of post-stroke patients comparing to healthy subjects.

Methods:

The CoM trajectory was obtained using a gold standard method, the three-dimensional (3D) kinematics associate to anthropometry. Two experimental groups were compared: Hemiparetic Group (HG) consisted of fourteen chronic hemiparetic patients and Control Group (CG) by fourteen able-bodied subjects.

Results:

The statistical analysis (P ≤ 0.05) revealed the following average gait alterations in the HG, in the stance phase of the affected side: higher lateral (midstance), lower vertical (midstance and terminal stance), and lower forward displacement (heel strike until terminal stance). In the swing phase of the affected side, HG showed higher lateral (preswing and initial swing) and vertical displacement (preswing until terminal swing), and lower forward (preswing until terminal swing) displacement of the CoM. There was also anticipation of the instants of maximum displacements in the lateral and vertical directions and lower total range in the forward direction.

Conclusion:

The CoM trajectory analysis pointed out that the gait after stroke was altered such in the affected as in the unaffected lower limbs, mainly in the single support phase of the affected side, but also in the swing phase of the gait cycle.

Keywords:

• Stroke
• Center of mass
• Gait analysis
• Biomechanics
• Walking