Persons with lower-limb amputation have impaired trunk postural control while maintaining seated balance

Area of Science:

• Biomechanics
• Neuroscience
• Rehabilitation Science

Background:

• Lower-limb amputation (LLA) can disrupt normal movement mechanics, potentially increasing spinal stability demands and altering postural control.
• Understanding these effects is crucial for managing long-term health consequences in individuals with LLA.

Purpose of the Study:

• To investigate the impact of unilateral lower-limb amputation on trunk postural control and stability during a seated balance task.
• To compare postural control strategies between individuals with LLA and healthy controls.

Main Methods:

• Utilized a seated balance task involving eight males with unilateral LLA (transtibial and transfemoral) and eight matched healthy controls.
• Employed traditional center of pressure (COP) measures and non-linear stabilogram diffusion analyses to assess trunk postural control.
• Measured normalized trunk muscle activity.

Main Results:

• Participants with LLA exhibited significantly larger traditional COP-based sway measures (ellipse area, RMS distance, mean velocity), indicating reduced trunk postural control.
• Non-linear analyses revealed significant differences in antero-posterior postural control for individuals with LLA.
• Normalized trunk muscle activity was elevated in the LLA group.

Conclusions:

• Unilateral LLA is associated with reduced trunk postural control and stability during seated balance.
• These deficits may stem from adaptations in neuromuscular responses and tissue properties, potentially increasing the risk of spinal instability and pain.
• Further research is needed to explore interventions mitigating these risks.