[Tridimensional gait analysis after unilateral subtalar arthrodesis]

Area of Science:

• Orthopedics
• Biomechanics
• Gait Analysis

Background:

• Subtalar arthrodesis is a surgical procedure used for various foot conditions, including deformities and traumatic injuries.
• The subtalar joint is crucial for transmitting rotational leg movements to the foot during gait.
• Previous studies have focused on clinical and radiological outcomes, but lacked 3D gait analysis.

Purpose of the Study:

• To perform a three-dimensional analysis of gait after subtalar arthrodesis.
• To evaluate the functional outcome and impact of subtalar fusion on gait parameters.

Main Methods:

• Gait analysis was conducted on 8 patients with unilateral subtalar arthrodesis using a Vicon VX3D system and force platforms.
• Kinematic, kinetic, and electromyographic (EMG) data were collected and analyzed.
• A Wilcoxon signed-rank test was used to compare operated and healthy sides.

Main Results:

• A significant difference in total joint movement amplitude was observed between the operated (16.5 degrees) and healthy (21.5 degrees) sides.
• Peak ankle plantar flexion power was reduced at the end of the stance phase in the operated limb.
• EMG recordings indicated a shift in muscle activity patterns between the fused and healthy foot.

Conclusions:

• Subtalar arthrodesis leads to a globally symmetrical gait pattern, with limited functional impact on the knee and hip.
• Despite reduced ankle flexion-extension amplitude, the overall gait remains symmetrical.
• Variability in movement amplitude was greater on the operated side compared to healthy subjects.