Background:
A prospective, cross-sectional, observational study was designed to determine the reliability of goniometric measurements in children with spastic diplegic cerebral palsy (CP).
Material/Methods:
The study included 38 children with spastic diplegic CP. Passive range of motion (PROM) of hip extension, abduction, and external rotation, hip flexion with knee extended, and ankle dorsi flexion was measured using universal goniometry. Each child was assessed by three physical therapists once in each session on two different sessions a week apart. Intra-test reliability was determined by paired comparison of measurements for each therapist across the two assessments. Inter-test reliability was determined by paired comparisons of the three therapists’ measurements on the same session. The interclass correlation coefficient (ICC) was calculated for intra- and inter-test reliability.
Results:
The mean absolute differences for all measures between sessions ranged from 0.10–4.86 degrees for the three physical therapists. There was no statistical significance in the mean differences between the physical therapists in all measurements (p>0.05) except for hip flexion with the knee extended (p<0.05). Inter-test reliability was high (p<0.01). The highest ICC value was 0.95 for hip extension and the lowest was 0.61 for hip abduction. Although the intra-testing reliability scores were high for all the physiotherapists, the most experienced physiotherapists’ results were higher compared with the others.
Conclusions: The results from this study encourage the use of goniometric measurements in assessing children with spastic diplegic CP.

Keywords: Research Design, Reproducibility of Results, Range of Motion, Articular, Prospective Studies, Physical Therapy Modalities, Physical Examination - methods, Observer Variation, Models, Statistical, Child, Cross-Sectional Studies, Child, Preschool, Arthrometry, Articular - methods, Cerebral Palsy - pathology