1st Joint ESMAC-GCMAS Meeting - Análise de Marcha

O-17
COMPARING THE RELIABILITY OF VIRTUAL GONIOMETRY AND UNIVERSAL
GONIOMETRY
Dunlevy, Colin, PhD 1 , Cooney, Marese, MMed 2 , Gormley, John, DPhil 2
1 Central Remedial Clinic, Dublin, Ireland. 2 Trinity College, Dublin, Ireland.
Summary/Conclusions
This study investigated the reliability of virtual goniometry (VG) and the universal goniometer
(UG) for the measurement of sagittal angles at the elbow and knee. VG measurements were
made by taking digital photographs of static joint angles, transferring the images to a PC and
finally manipulated computer software’s virtual measurement arms (VMA) to calculate the
joint angle. Three different examiners were used and both intra-rater and inter-rate reliability
was investigated. Four different approaches to the alignment of the VMAs over the joint
images were tested. Alignment of the VMAs along anterior-posterior bisection points of the
limb segments provided the strongest reliability. The use of adhesive markers at anatomical
landmarks did not improve reliability. The standard UG was shown to have poor reliability
scores compared with VG.
Introduction
The aspiration for a scientific approach to the management of neuromuscular and orthopaedic
disease has a fundamental requirement for accurate measurement tools. Reliable tools that
allow the clinician to monitor joint range of movement and function and to determine the effect
of particular interventions are required. The literature has not shown the standard UG as having
strong reliability and VG tools such as the Uillinn Method© [1] or the Internet Based
Goniometer [2] have been proposed as an alternative to UG. A comparison between the
reliability scores for the VG and UG would help determine optimal measurement practice.
Statement of clinical significance
This study presented data on the reliability of VG and compared it to the reliability of the
standard UG. The results provide clinically relevant information regarding the anticipated error
associated with routine static joint angle measurement and suggests ways to improve
measurement accuracy.
Methods
Measurements of sagittal joint angles at the knee and elbow were used in this study. The VG
used in this study was the Uillinn Method© [1]. The 4 different approaches to applying the
VMAs about the joints were; the No Marker method which had the examiners place the VMAs
where they perceived the standard anatomical landmarks to be (skin markers were not used),
the Parallel method placed the VMAs over the approximated longitudinal axis of the limb
segments, the Mid-Point method used additional software markers to identify the anteriorposterior
bisection at different points along the limb segments. These were then used as a guide
to placing the VMAs. Finally, the Skin Marker method used 3 small adhesive markers placed at
anatomical landmarks upon which to align the VMAs. Each of the subjects involved in the
testing were required to remain stationary for 15 minutes while 3 chartered physiotherapists
repeatedly measured and photographed the 51 individual knees and 49 elbows that were placed
in random positions. Healthy subjects were chosen to minimise biological error. Data was
gathered for both intra-rater and inter-rater reliability for both the UG and each of the 4 VMA
placement methods. Blinded precautions were observed. The agreement statistics used were the
Repeatability coefficient (RC), Limits of Agreement (LOA) and Typical Error (TE) which
provided clinically relevant data. Correlation coefficients (ICC) were also used to complete the
analysis.
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