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Kinematic differences between children with obstetric brachial plexus palsy and healthy controls while performing
Judy Mahon1, Ailish Malone2, Damien Kiernan1
1Gait Analysis Laboratory, Central Remedial Clinic, Vernon Ave., Clontarf, Dublin 3, Ireland.
Insights
Children with obstetric brachial plexus palsy exhibit distinct shoulder movement differences compared to typically developing peers. This study quantifies kinematic deviations in shoulder joint function during functional tasks.
Area of Science:
- Orthopedics
- Pediatric Rehabilitation
- Biomechanics
Background:
- Obstetric brachial plexus palsy (OBPP) often results in residual shoulder dysfunction impacting functional performance.
- Observational assessment alone is insufficient for understanding upper limb dynamic movement patterns in OBPP.
- This study investigates kinematic differences in children with OBPP during functional tasks.
Purpose of the Study:
- To quantify three-dimensional upper limb kinematic differences between children with OBPP and typically developing controls.
- To identify specific joint-level deviations contributing to functional deficits in OBPP.
- To provide objective data for understanding shoulder dysfunction in OBPP.
Main Methods:
- A case-control study involving 11 children with OBPP and 10 typically developing children.
- Three-dimensional upper limb motion analysis using an optoelectronic tracking system and the acromion method.
- Kinematic data collection during modified Mallet Scale tasks, analyzing glenohumeral, thoracohumeral, and scapulohumeral joint rotations.
Main Results:
- Children with OBPP showed increased internal rotation, reduced glenohumeral excursion, and a habitual "trumpet" posture.
- Scapulohumeral rhythm was significantly altered in children with OBPP (1.04:1) compared to controls (1.88:1) during abduction.
- Deficient external rotation and compromised internal rotation range were observed in OBPP.
Conclusions:
- Children with OBPP exhibit significant kinematic deviations in shoulder joint function, particularly affecting external rotation and scapulohumeral rhythm.
- The glenohumeral joint's range deficit is a key contributor to abnormal movement patterns.
- Objective kinematic analysis is crucial for understanding and addressing shoulder dysfunction in OBPP, with potential for Narakas Classification subgroup analysis.
Background:
Residual shoulder dysfunction and deformity impacts on functional performance in children with obstetric brachial plexus palsy. Clinical understanding of upper limb dynamic movement patterns is difficult with observation alone. This case-control study describes the significant kinematic differences between children with obstetric brachial plexus palsy compared to typically developing children while performing tasks of the modified Mallet Scale.
Methods:
Eleven children with obstetric brachial plexus palsy (mean 10 years, range 7-15 years, Narakas group I-III) and 10 typically developing children (mean 9 years 9 months, range 6-15 years) completed three-dimensional upper limb motion analysis using the acromion method to track dynamic scapular movement. Kinematic data were captured by a 4-CODA cx1 optoelectronic tracking system. Participants performed three trials of the modified Mallet scale tasks. Local coordinate systems, segment and joint rotations were defined as recommended by the International Society of Biomechanics.
Findings:
Joint rotation angles against time of the glenohumeral, thoracohumeral and scapulohumeral joints were calculated. Kinematic findings demonstrated increased internal rotation in all postures, reduced glenohumeral excursion, habitual "trumpet" posture of glenohumeral abduction/elevation and variability in movement strategies. Scapulohumeral rhythm during abduction task was 1.88:1 in typically developing children and 1.04:1 in children with obstetric brachial plexus palsy.
Interpretation:
Children with obstetric brachial plexus palsy demonstrate deficient external rotation in all tasks. Despite increased postural internal rotation, ability to move through internal rotation range is compromised. The glenohumeral joint showed the greatest range deficit, contributing to abnormal scapulohumeral rhythm. Future sub-group analysis of Narakas Classification is recommended.
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