Comparison of Shoulder Motion Measurements by Visual Estimate, Goniometer and Motion Capture

Area of Science:

• Orthopedics
• Pediatric Rehabilitation
• Biomechanics

Background:

• Brachial plexus birth injuries (BPBI) can cause long-term impairments in shoulder external rotation and cross-body adduction.
• These impairments significantly affect daily functional activities like dressing and grooming.

Purpose of the Study:

• To compare the accuracy of three methods for quantifying shoulder humerothoracic (HT) external rotation (ER) and glenohumeral (GH) cross-body adduction (CBA) in children with BPBI.
• Methods compared include physician visual estimation, goniometer measurement by an occupational therapist, and motion capture technology.

Main Methods:

• Twenty-six pediatric patients with BPBI underwent assessment.
• Measurements included passive HT ER and GH CBA via visual estimate and goniometer, alongside simultaneous motion capture.
• Active HT ER was also measured using motion capture.

Main Results:

• GH CBA measures showed good agreement but substantial variation between methods.
• HT ER measures exhibited significant differences and poor agreement across all methods.
• Motion capture data revealed that physicians misclassified 79% of external rotation Mallet scores, consistently overestimating the range.

Conclusions:

• Significant variability exists in shoulder range of motion measurements for BPBI patients across different assessment techniques.
• Motion capture offers superior accuracy by minimizing compensatory movements, making it ideal for clinical assessment.
• When motion capture is unavailable, goniometry is preferred over visual estimates for more reliable clinical measures.