Comparison of Foot Kinematics Between Normal Arch and Flexible Flatfoot Using the Oxford Foot Model: A Matched Case-Control Study

Background

Symptomatic flexible flatfoot causes alterations in gait, but exactly how this condition affects the intersegmental motion of the foot during the gait cycle remains unclear. Previous studies have examined the kinematics, yielding inconsistent findings. Therefore, the objective of this study was to investigate how flexible flatfoot deformity, defined as Johnson and Strom classification staging II, affects the intersegmental motion of the foot during fast walking based on a comparison with the matched control group.

Methods

Eleven participants with symptomatic flexible flatfoot and 11 healthy matched control participants were recruited using a foot screening protocol incorporated through a foot physical examinations and radiographic measurements. All demographic characteristics exhibited comparable profiles between the groups. During controlled walking, kinematic outcomes pertaining to the hallux, hindfoot, forefoot, and tibia were collected using the multisegmental Oxford Foot Model.

Results

All spatiotemporal parameters were comparable between the groups. In comparison to the control group, individuals with symptomatic flexible flatfoot demonstrated increased hallux valgus and plantarflexion, increased forefoot abduction, heightened hindfoot eversion, and internal rotation. Notably, no significant major differences were observed in the tibia motion segment. Further, significant correlations were identified between static foot measurements and the extent of the maximum deviation observed during dynamic kinematic assessments.

Conclusion

Compared with age- and gender-matched controls, participants with symptomatic flexible flatfoot exhibited significant gait pattern deviations. A significant correlation also exists between static foot deformity measurements and dynamic kinematic deviations. Collectively, these findings have implications for developing targeted therapeutic interventions to address flexible flatfoot.

Level of evidence

Level III, diagnostic study.

Comparing the Efficacy of Long Spinal Board, Sked Stretcher, and Vacuum Mattress in Cervical Spine Immobilization; a Method-Oriented Experimental Study

Introduction

Inadequate spinal motion restriction in patients suffering from spinal injuries could lead to further neurological damage, ultimately worsening their prognosis. This study aimed to investigate the efficacy of long spinal boards (LSB), ske stretcher, and vacuum mattress for cervical spine immobilization during transportation of patients by measuring the angular motion of the cervical spine following lifting, transferring, and tilting.

Methods

We conducted an experimental study using a box of three randomizations and crossover designs without a washout period effect for the long spinal board, sked stretcher, and vacuum mattress. We concealed the randomization with sequentially numbered, opaque, sealed envelopes (SNOSE). Kinematic data were collected using eight optoelectronic cameras at 200 Hz (BTS Bioengineering, Milan, Italy) in triangular planes (lateral bending, flexion-extension, and axial rotation) while performing all three motions (static lift-hold, transfer, and 90° tilt).

Results

12 cases (7 males and 5 females) with the mean age of 20 ± 3.03 (range: 18-28) years were studied. The three highest angular motions were observed in the axial rotation plane during patient's tilting under immobilization on all devices (Vacuum mattress having the highest value of 99.01±8.93, followed by the LSB at 89.89±34.35 and the sked stretcher at 86.30±7.73 degrees). During patient lifting, a higher angular motion was observed with vacuum mattress immobilization in flexion extension (Coefficient = 4.45; 95%CI: 0.46 - 8.45; p =0.029) and axial rotation (Coefficient = 3.70; 95%CI: 0.58 - 6.81; p =0.020) planes. During patient transfer, a higher angular motion was observed with sked stretcher in the flexion-extension plane (Coefficient = 2.98; 95%CI: 0.11 - 5.84; p = 0.042). During patient tilting to 90 degrees, a higher angular motion was observed with vacuum mattress immobilization in lateral bending (Coefficient = -4.08; 95%CI: -7.68 - -0.48; p = 0.026) for the vacuum mattress.

Conclusion

Based on the finding of the present study, patients on the vacuum mattress experience significantly higher angular motion in flexion extension and axial rotation during lifting, as well as lateral bending during 90-degree tilting. In addition, patients on the sked stretcher showed significantly higher angular motion in flexion-extension during the transferring. However, the predictive margins for immobilization across all devices did not demonstrate clinically significant differences among the three immobilization devices.