Dynamic analysis of trunk flexion after stroke

Area of Science:

• Biomechanics
• Neurology
• Rehabilitation Science

Background:

• Stroke-associated hemiparesis significantly impacts motor control and functional mobility.
• Understanding trunk movement and weight distribution is crucial for effective rehabilitation strategies.

Purpose of the Study:

• To quantitatively assess trunk movement and lower-extremity weight bearing in individuals with hemiparesis compared to healthy controls.
• To elucidate the biomechanical adaptations following stroke.

Main Methods:

• A controlled study involving 15 participants with hemiparesis and 13 healthy controls.
• Participants performed a trunk flexion task to touch a target while seated on forceplates.
• Key outcome measures included trunk movement amplitude and speed, center of pressure (COP) displacement, and weight distribution on buttocks and feet.

Main Results:

• Participants with hemiparesis demonstrated comparable trunk movement speed and amplitude to healthy subjects.
• However, individuals with hemiparesis showed significantly reduced COP displacement.
• Lower weight bearing on the feet was observed in the hemiparetic group for both paretic and non-paretic limbs.

Conclusions:

• Reduced COP displacement and lower foot weight bearing in hemiparetic individuals suggest altered body mass anterior displacement.
• Trunk movements in hemiparesis may rely more on upper trunk motion with limited pelvic tilt.
• These findings highlight potential targets for physical therapy interventions to improve weight distribution and postural control.