A preliminary investigation of the role of the upper limb during stair ascent in children with mild cerebral palsy: biomechanical and clinical perspectives

Chercheurs: Désirée B. Maltais PhD, PT, Bradford J. McFadyen PhD, Francine Malouin PhD, PT, Carol L. Richards PhD, DU, PT.
Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Laval University, Quebec City, Canada.

Objectives:
To determine, for children with mild cerebral palsy (CP); 1) the role of the upper limb during stair ascent, and 2) relationships between stair locomotion (momentum and spatial-temporal variables) and clinical measures of upper and lower limb muscle strength and walking skill.

Methods:
Fifteen, 7-12 yr old children with mild CP (Gross Motor Function Classification System Level I) are participating in the study. Strength of relevant upper and lower limb muscles is being determined bilaterally using a hand-held dynamometer. Walking skill is being assessed using the Walking, Running and Jumping Dimension of the Gross Motor Function Measure and by determining comfortable and fast over ground walking speeds. Kinematic and kinetic data are being collected while children ascend a custom-made, 5-step, adjustable staircase at their preferred speed. The participants ascend the stairs using four different strategies: 1) a tandem (two feet on the same step) lower limb strategy using handrail, 2) a reciprocal (one foot per step) lower limb strategy using a handrail, 3) a tandem strategy without using a handrail and, 4) a reciprocal strategy without using a handrail. The children always lead with the lower limb ipsilateral to their dominant upper limb and use the handrail with their dominant upper limb. A two-way repeated measures ANOVA is being used to assess the effect of the upper limb (handrail or no handrail use) and lower limb (tandem or reciprocal pattern) strategies on stair locomotion during stair ascent. The relationships between the stair locomotion variables and the clinical measures of muscle strength and walking skill are being analysed using linear correlation techniques. Multiple regression analyses are being used to determine the relative importance of the different gross motor skill and muscle strength variables with respect to each locomotion variable (under the various stair ascent strategies).

Results:
– Faster without handrail
– Applied force at handrail mostly in backwards and downwards directions
– Maintain contact with handrail
– Clinical measures of muscle strength may predict handrail use: Dominant ankle dorsiflexors / Dominant knee extensors.