Influence of the moving fluoroscope on gait patterns

Area of Science:

• Biomechanics
• Medical Imaging Technology
• Orthopedic Surgery

Background:

• Video-fluoroscopic analysis offers in vivo assessment of tibiofemoral kinematics after total knee arthroplasty, crucial for evaluating outcomes.
• Robotic moving fluoroscope systems track knee motion during daily activities like gait, but their impact on normal gait is unclear.

Purpose of the Study:

• To investigate the influence of a moving fluoroscope on gait characteristics in healthy young and elderly subjects.
• To analyze the impact of the robotic system's motor noise on gait parameters.

Main Methods:

• Simultaneous measurement of skin markers (VICON MX) and ground reaction forces (Kistler) during level gait and stair descent.
• Comparison of gait with and without the moving fluoroscope, and with and without ear protectors.

Main Results:

• Walking with the moving fluoroscope significantly decreased gait velocity in both level gait and stair descent.
• No significant differences were found in ground reaction force parameters when gait velocity was accounted for.
• Minor alterations in kinematic parameters (joint range of motion) were observed, but statistical significance was limited by velocity differences.

Conclusions:

• Moving fluoroscope use leads to small gait alterations, primarily reduced velocity, which are comparable to natural slow walking.
• While ground reaction forces are unaffected (velocity-adjusted), kinematic changes suggest caution when comparing data to self-selected speed walking.
• The findings support the use of moving fluoroscopes for comparative studies within the system but highlight the need for optimization for higher gait velocities and careful interpretation when comparing to unencumbered walking.