Characterizing inter-limb synchronization after incomplete spinal cord injury: A cross-sectional study

Area of Science:

• Neuroscience
• Biomechanics
• Rehabilitation Science

Background:

• Individuals with incomplete spinal cord injury (iSCI) exhibit greater postural sway and rely more on vision for balance.
• Previous research on iSCI balance focused on lower limb contributions, overlooking inter-limb synchrony, a key balance indicator in other neurological conditions.

Purpose of the Study:

• To investigate how incomplete spinal cord injury (iSCI) affects inter-limb synchrony and weight-bearing symmetry during quiet standing.
• To determine the role of inter-limb coordination in the impaired standing balance observed in individuals with iSCI.

Main Methods:

• Compared 18 individuals with iSCI to 15 able-bodied individuals (M-AB) using force plates to measure centre-of-pressure (COP) metrics.
• Assessed COP root mean square (RMS), velocity, inter-limb synchrony (cross-correlation), and weight-bearing asymmetry under eyes-open and eyes-closed conditions.
• Evaluated lower limb muscle strength using manual muscle testing.

Main Results:

• Individuals with iSCI exhibited significantly reduced COP inter-limb synchrony in both visual conditions compared to M-AB.
• No significant differences in weight-bearing asymmetry were found between iSCI and M-AB groups.
• Individuals with iSCI demonstrated greater net COP RMS and velocity, indicating poorer postural control, and showed asymmetry in lower limb muscle strength.

Conclusions:

• Incomplete spinal cord injury (iSCI) impairs standing balance, characterized by reduced inter-limb synchrony and increased COP sway.
• Findings suggest that impaired coordination between lower limbs contributes to balance deficits in individuals with iSCI.
• This research provides insights for improved balance assessment and interventions for the iSCI population, highlighting the need for future studies on falls risk.