What is the Gait Profile Score?
The Gait Profile Score (GPS) is a summary measure of kinematic gait data1. It quantifies the deviation of a selection kinematic variables for an individual from a non impaired control population. The GPS is usually given as the overall score for both limbs, but separate scores for each limb can also be calculated. The Movement Analysis Profile (MAP) breaks down the GPS the give the contribution of each individual kinematic component. As they are derived from joint angles, all GPS and MAP values are in degrees. The minimal clinically important difference (MCID) has been determined to be 1.6o, based on a correlation with an established clinical score (Functional Assessment Questionnaire, or FAQ)2. It has also been shown to have a strong relationship to clinical judgement among clinicians experienced in gait analysis3.
Which kinematic variables are used?
The variables were chosen on the basis of clinical importance and reliability.
Pelvic Tilt, Pelvic Obliquity, Pelvic Rotation Hip Flexion, Hip Abduction Knee Flexion Ankle Dorsiflexion Foot Progression
As there is only one pelvis segment, only the values from one side are used. Bilateral joint angles are used for all of the other variables.
How is the GPS Calculated
The GPS is the root mean square (RMS) difference between an individuals kinematic data, for all of the above variables, and the mean data from a non impaired control group, across a gait cycle. The MAP for a given variable is simply the RMS difference between the joint angle for an individual and that of the control group across the gait cycle.
Refs:
[1] Baker R et al (2009) The Gait Profile Score and Movement Analysis Profile. Gait Posture 30:265-269
[2] Baker R et al (2012) The minimal clinically important difference for the Gait Profile Score. Gait Posture 35:612-615
[3] Benyon S et al (2010) Correlations of the Gait Profile Score and the Movement Analysis Profile relative to clinical judgments. Gait Posture 32:129-132.
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