1st Joint ESMAC-GCMAS Meeting - Análise de Marcha

medial area of the midfoot region for 28.7% of stance. The COPP then moves from the
midfoot into the forefoot region where it progresses medially and forward passing just lateral
to the hallux. The period of time the COPP spends in the forefoot is 47.5% of stance phase.
The results for the comparative analysis of the two methods of long axis determination are
shown in figure 2. The A-T method used 3D kinematic data to determine the long axis of the
foot. This method is consistent with common gait analysis approaches for measuring foot
progression angle. The remaining eight bars in the graph show the long axis angle for the two
repetitions of manual long axis selection by each analyst. Three analysts were within one
degree of the A-T method, while the fourth analyst, B, was approximately two degrees less
than the A-T method. Statistical analysis found significant differences between the methods,
but no differences between the analysts. Excellent intra-rater, 0.975, and inter-rater, 0.969,
reliability was observed .
11 12 13
14 15
6 7
1 2
16.00
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
- 173 -
Foot angle
A-T G1 G2 L1 L2 J1 J2 B1 B2
Discussion
The statistical differences shown reflect absolute differences less than 2 degrees, these
differences may offer little clinical relevance. With the data stratified into the medial to lateral
areas of the heel, midfoot and forefoot clinical classifications can be generated, i.e. varus,
valgus, severe varus, severe valgus, equinus, calcaneous, and normal. These results give
reasonable confidence that manually selecting the long axis is an acceptable method for feet
that are normally shaped. However, using the subjective method for malalligned feet or feet in
equinus or varus may not reflect the same level of confidence. This technique provides a
rational basis for an objective clinical classification of dynamic foot deformities.
References
1. Stokes, IAF, et al. (1975). Acta Orthop Scand, 46, 839-47
2. Duckworth, T, et al. (1985). J. Bone and Joint Surgery, 67, 79-85
3. Chang, CH, et al. (2002). J. Pediatric Orthop, 22, 813-18
4. Bowen, TR, et al (1998). J. Pediatric Orthop, 18, 789-93
5. Jameson, GG (2004). Dev Med Child Neurol, 99, 34
Figure 2. Foot Angle Means and Standard
Deviations.
The A-T method employs 3D kinematics to determine
the long axis of the foot. The subjective method was
performed by four observers (G, L, J, & B), two times
for each trial.
Figure 1. Mean COPP.
Dark gray band is mean +/- one standard
deviation; light gray is mean +/- two
standard deviations.