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Frame-by-Frame Video Analysis of Idiosyncratic Reach-to-Grasp Movements in Humans
Published on: January 15, 2018
Reliability of kinematic measures of functional reaching in children with cerebral palsy
Sheila Schneiberg1, Patricia McKinley, Erika Gisel
1Centre for Interdisciplinary Research in Rehabilitation, Montreal, Quebec, Canada.
Insights
Kinematic measures show reliable upper limb movement in children with cerebral palsy (CP). These variables can assess rehabilitation effectiveness, but reliability depends on the specific reaching task.
Area of Science:
- Pediatric rehabilitation
- Movement science
- Biomechanical analysis
Background:
- Rehabilitation effectiveness in children with cerebral palsy (CP) relies on precise outcome measures.
- Kinematic analysis offers objective metrics for motor function.
Purpose of the Study:
- To evaluate the test-retest reliability of kinematic measures for upper limb reaching movements in children with CP.
- To determine the suitability of kinematic variables as outcome measures in clinical trials for CP.
Main Methods:
- Thirteen children with CP (MACS levels II-IV) were assessed three times over five weeks.
- Kinematics of the more affected arm reaching for a block at varying distances were analyzed.
- Six kinematic variables, including trajectory straightness, smoothness, and joint displacements, were measured and reliability calculated using intraclass correlation coefficients (ICCs).
Main Results:
- High reliability (ICCs 0.82-0.95) was found for trajectory smoothness, trunk displacement, elbow extension, and shoulder flexion (far target).
- Other variables showed moderate to low reliability (ICCs 0.17-0.81).
- Test-retest reliability was influenced by task demands, such as trunk displacement and joint excursion.
Conclusions:
- Kinematic variables demonstrate potential as reliable outcome measures for assessing upper limb motor performance and movement quality in children with CP.
- The task-specific nature of kinematic reliability necessitates careful consideration of task requirements when interpreting results for clinical trials.
Aim:
The determination of rehabilitation effectiveness in children with cerebral palsy (CP) depends on the metric properties of the outcome measure. We evaluated the reliability of kinematic measures of functional upper limb reaching movements in children with CP.
Method:
Thirteen children (ten females, three males) with spastic hemiplegic, diplegic, or quadriplegic CP affecting at least one arm (mean age 9y, SD 1.6y; range 6-11y; Manual Ability Classification System [MACS] levels II-IV) were evaluated three times over 5 weeks. The kinematics of the more affected arm reaching to grasp a 2cm(3) block placed at three distances from the body midline were analysed. The reliability (test-retest) of six kinematic variables (endpoint trajectory straightness and smoothness, trunk displacement, elbow extension, shoulder horizontal adduction, and shoulder flexion] was tested and expressed as intraclass correlation coefficients (ICC, model 2,K) and 95% confidence intervals.
Results:
Trajectory smoothness, trunk displacement, elbow extension, and shoulder flexion (far target) had the highest ICCs (0.82-0.95). Other kinematic variables had moderate (0.50< or =ICC< or =0.81) or low (0.17-0.38) reliability. Test-retest reliability was task dependent, as reaches required different degrees of trunk displacement and joint excursion.
Interpretation:
Kinematic variables can be used as outcomes in clinical trials to test upper limb intervention effectiveness on motor performance and movement quality. As kinematic variables are task specific, reliability should be interpreted in the context of task requirements.
