Minute-by-minute differences in co-activation during treadmill walking in cerebral palsy

Area of Science:

• Neurology
• Biomechanics
• Pediatrics

Background:

• Spastic cerebral palsy (CP) often affects gait, leading to challenges in muscle coordination and movement efficiency.
• Understanding muscle co-activation patterns during walking is crucial for developing targeted interventions in pediatric CP.
• Treadmill training is a common rehabilitation strategy, but optimal practice durations for gait parameter stabilization are not fully established.

Purpose of the Study:

• To investigate minute-by-minute changes in lower limb antagonist muscle co-activation and stride length (SL) during treadmill walking in children with mild spastic CP.
• To determine if muscle co-activation patterns are influenced by the site (thigh or lower leg) and dominance of the lower limb.
• To assess differences in co-activation between dominant and non-dominant lower limbs.

Main Methods:

• Eight independently ambulatory children and adolescents with mild spastic CP (ages 9.2-15.7 years) participated.
• Minute-by-minute lower limb antagonist muscle co-activation and SL were recorded during a 3-minute treadmill walk at 90% of their fastest speed.
• Data were analyzed to identify changes over time and differences based on limb dominance and muscle site.

Main Results:

• Non-dominant thigh co-activation decreased significantly within the first two minutes of walking.
• Dominant lower leg co-activation showed a reduction by the third minute.
• Thigh co-activation was consistently higher than lower leg co-activation, irrespective of limb dominance or time. Non-dominant thigh co-activation was notably higher than dominant thigh co-activation.

Conclusions:

• 12-15 minutes of treadmill walking practice appears sufficient to achieve stable co-activation and stride length measurements by the second minute of a fast-paced walk.
• Limb dominance and the specific muscle site (thigh vs. lower leg) significantly impact the magnitude of muscle co-activation during gait in pediatric CP.
• These findings suggest that gait training protocols should consider limb-specific and site-specific characteristics for optimal outcomes in children with spastic CP.