Abstract
Category:
Midfoot/Forefoot
Introduction/Purpose:
Acquired adult flatfoot is thought to be caused by a loss of the dynamic and static supportive structure of the medial longitudinal arch. Current evaluation systems mostly rely on static measurements such as standing x-ray, CT and MRI. Recently, the gait analysis has been suggested to be a good tool for assessment of functional impairment. Although there are some previous investigations about gait of flatfoot, there was a limitation in control groups in terms of matching age and gender. The objective of this study was to find the effect of the acquired adult flatfoot on the segmental motion of the foot during gait by comparisons with age and gender controlled healthy adults.
Methods:
20 symptomatic flatfeet (12 female patients, 51–80 years old) and 50 symptom-free normal feet (50 female participants, 60-69 years old) were included in this study. For radiographic examinations, meary angle, calcaneal pitch, talo-calcaneal angle, tibio-calcaneal angle was measured using standing lateral radiograph of the foot. And talonavicular coverage angle was measured using standing anteroposterior radiograph of the foot. For foot gait analysis, the temporal gait parameters such as cadence, speed, stride length, step width, step time were calculated. Segmental foot kinematics evaluated using a 3D MFM of a 15-marker set (Foot3D model). Inter-segmental angles (ISA) (hindfoot relative to tibia, forefoot to hindfoot, and hallux to forefoot) were calculated at each time points (100 time points for whole gait cycle). The ISAs (position) at specific phases of gait cycle, the change of ISA (motion) between phases and range of ISAs during the whole gait cycle were calculated and compared between groups.
Results:
Range of motion (ROM) of sagittal and transverse plane of hindfoot, and transverse plane of forefoot was lower in flatfoot group. ROM of coronal plane of hallux and sagittal plane of forefoot was higher in flatfoot group. There also are significantly different findings in flatfoot group such as more dorsiflexed position of forefoot segment, reduced forefoot abduction motion during terminal stance and loss of push off during preswing phase. In addition, the time of push off phase in flatfoot group occurred later than the control group. In other words, lag of stance phase occurred in flatfoot group (Figure 1). This tendency became even worse when the moderate group and the severe group were compared based on the -20 ° of meary angle.
Conclusion:
As shown in the gait analysis, the overall reduction in hindfoot ROM and the increase in forefoot ROM in the flatfoot group suggest a midfoot breakage, which shows a decrease in push off power and a lag in the stance phase. So, the results of this study suggest that altered segmental motion of the foot in acquired adult flatfoot patients with PTTD, which shows progressive deterioration according to severity. And we think that gait analysis can be used as an objective functional measurement system for evaluation of acquired adult flatfoot patients.