Sagittal Fluoroscopy for the Assessment of Hindfoot Kinematics

Abstract

Current methods of quantifying foot kinematics during gait typically use markers placed externally on bony anatomic locations. These models are unable to analyze talocrural or subtalar motion because the talus lacks palpable landmarks to place external markers. Alternative methods of measuring these clinically relevant joint motions are invasive and have been limited to research purposes only. This study explores the use of fluoroscopy to noninvasively quantify talocrural and subtalar sagittal plane kinematics. A fluoroscopy system (FS) was designed and built to synchronize with an existing motion analysis system (MAS). Simultaneous fluoroscopic, marker motion, and ground reaction force (GRF) data were collected for five subjects to demonstrate system application. A hindfoot sagittal plane model was developed to evaluate talocrural and subtalar joint motion. Maximum talocrural plantar and dorsiflexion angles averaged among all the subjects occur at 12% and 83% of stance, respectively, with a range of motion of 20.1 deg. Maximum talocrural plantar and dorsiflexion angles averaged among all the subjects occur at toe-off and 67% of stance, respectively, with a range of motion of 8.7 deg. Based on the favorable comparison between the current fluoroscopically measured kinematics and previously reported results from alternative methods, it is concluded that fluoroscopic technology is well suited for measuring the sagittal plane hindfoot motion.

Segmental kinematic analysis of planovalgus feet during walking in children with cerebral palsy

“…Shultz et al, used single-plane fluoroscopy to report a maximum of 16 mm translational soft tissue artifact at the navicular, up to 13.2 mm at the calcaneus, and less than 1° rotational artifact in hindfoot and forefoot marker clusters [28]. Fluoroscopy has been used to avoid soft tissue artifact and track talocrural and subtalar motion during gait [29] but such systems are not widely available and much more costly than foot models which can be implemented in standard gait laboratories. Other limitations to these systems include a small field of view and concerns with radiation dosage.…”

Sagittal Subtalar and Talocrural Joint Assessment During Ambulation With Controlled Ankle Movement (CAM) Boots

“…The barefoot talocrural sagittal plane kinematics reported in this study are similar in magnitude and trend with those previously reported by our group. 8,9 In a 13-subject study published in 2014, we reported 11.2 degrees of maximum talocrural plantarflexion and −7.5 degrees of maximum dorsiflexion (18.1 degrees of ROM in the sagittal plane). 9 The currently reported maximum plantar and dorsiflexion angles are 9.2 degrees and −7.5 degrees, respectively (16.7 degrees ROM).…”

“…This method has previously been shown to have errors less than 2 mm with subject foot progression angles of ±5 degrees. 8 Average foot progression angle for the current study was −1.7 degrees (n=233, 191 dynamic trials and 42 static). These translated points of interest were defined in the sagittal plane of the foot and were then used to describe local coordinate systems for the talus and calcaneus.…”

“…The kinematic model used in this study applied a combination of motion and fluoroscopic data and has previously been used to describe barefoot sagittal plane talocrural and subtalar motion while walking. 8,9 This fluoroscopic system has been evaluated and barefoot results have been compared to other studies using implanted bone pins. 1,7,9 In this institutional review board (IRB)-approved study, 14 male subjects (mean age 24.1 ± 3.5 years) screened for exclusion criteria gave written informed consent prior to being tested walking barefoot, in a short CAM boot (Short Walking Brace, Ovation Medical, Agoura Hills, CA), and in a tall CAM boot (Standard Walking Brace, Ovation Medical, Agoura Hills, CA) ( Figure 1).…”

Sagittal Subtalar and Talocrural Joint Assessment Between Barefoot and Shod Walking: A Fluoroscopic Study

“…Exclusion criteria included any significant injury to the foot/ankle or any previous lower extremity surgery (bilateral). The data capture system consisted of a modified fluoroscopy unit [20] placed within an existing Vicon motion analysis capture volume (Vicon Motion Systems, Inc., Oxford, UK).…”