Locomotor Assisted Therapy's Influence on Lower Extremity Muscle Activation Patterns in Typically Developing Children and Children With Cerebral Palsy

Abstract

<h3>Research Objectives</h3> To compare muscle activation patterns of children with cerebral palsy (CP) and typically developing (TD) in overground (OG) and driven gait orthosis (DGO) walking. To compare within group variability of each muscle and walking condition. <h3>Design</h3> Nonrandomized controlled trial, no follow-up. <h3>Setting</h3> Neuroscience Center at IU Health (primary care facility). <h3>Participants</h3> Volunteer sample of twenty subjects, 10 with CP and 10 age-matched TD, aged 4 to 11 years. CP inclusion criteria: ability to ambulate 20 feet barefoot and ability to follow one step directions. Exclusion criteria: Botox to the lower extremity in last 3 months and history of tendon transfer. No subjects refused or withdrew. <h3>Interventions</h3> Rectus femoris (RF), semitendinosus (ST), gluteus maximus (GMax), and gluteus medius (GMed) surface EMG were recorded in OG and DGO conditions for three 10 second intervals. <h3>Main Outcome Measures</h3> Averaged surface EMG gait cycle time normalized values. <h3>Results</h3> Between group muscle activation pattern analysis revealed consistent differences (p < .05) in terminal stance, pre-swing, and initial swing phases of gait with greater muscle unit recruitment during DGO walking. Within group variability of the muscle activation patterns revealed lower muscle activation variability in CP DGO walking (RF 52.82%, ST 69.20%, GMax 20.36%, GMed 49.74%) compared to CP OG (RF 51.40%, ST 38.50%, GMax 5.62%, GMed 37.04%). <h3>Conclusions</h3> Decreased variability indicates that walking in the DGO provided measurably repetitive movement. Consistent elevated muscle unit recruitment noted in DGO walking in terminal stance, pre-swing, and initial swing may be due to the negative effect that the DGO parameters of guidance force, body weight support, and speed may have on ground reaction force. With the goal of normalizing functional gait, study on the effect of these parameters on ground reaction forces is needed. <h3>Author(s) Disclosures</h3> N/A.