A clinically applicable six‐segmented foot model

Abstract

We describe a multi-segmented foot model comprising lower leg, rearfoot, midfoot, lateral forefoot, medial forefoot, and hallux for routine use in a clinical setting. The Ghent Foot Model describes the kinematic patterns of functional units of the foot, especially the midfoot, to investigate patient populations where midfoot deformation or dysfunction is an important feature, for example, rheumatoid arthritis patients. Data were obtained from surface markers by a 6 camera motion capture system at 500 Hz. Ten healthy subjects walked barefoot along a 12 m walkway at self-selected speed. Joint angles (rearfoot to shank, midfoot to rearfoot, lateral and medial forefoot to midfoot, and hallux to medial forefoot) in the sagittal, frontal, and transverse plane are reported according to anatomically based reference frames. These angles were calculated and reported during the foot rollover phases in stance, detected by synchronized plantar pressure measurements. Repeated measurements of each subject revealed low intra-subject variability, varying between 0.78 and 2.38 for the minimum values, between 0.58 and 2.18 for the maximum values, and between 0.88 and 5.88 for the ROM. The described movement patterns were repeatable and consistent with biomechanical and clinical knowledge. As such, the Ghent Foot model permits intersegment, in vivo motion measurement of the foot, which is crucial for both clinical and research applications. Keywords: multi-segment foot model; foot and ankle kinematics; gait analysis; Ghent Foot Model Multi-segmented foot models can provide better insight into foot kinematics (and to a less extent segmental foot kinetics) during gait than single segments models. Clinically, they are used to describe and analyze functional characteristics associated with foot impairments. A number of multi-segmented foot models, using either bone pins or surface markers, have been proposed. They vary according to the number of segments and functional unit definition, in the methods of calculating intersegment angles, and in the definition of the neutral foot reference position. 1,2The need exists for a clinically relevant, user-friendly multi-segment foot model that would include the lower leg, hindfoot, midfoot, medial and lateral forefoot, and the hallux, with wide utility to investigate single joint/segment joint dysfunction through to complex foot deformities. Models with <5 segments often can not describe whole foot kinematics. [3][4][5][6][7] In contrast, those with nine segments 8 are not always easily applicable in clinical settings. To our knowledge and based upon a recent review, 2 no such model is currently available.There are two main reasons why a 6 segment model is clinically relevant. First, these segments are examined clinically by physical therapists and podiatrists. The medial arch, formed by the rearfoot (talus), the medial part of the midfoot, and the first ray, plays an important role in foot function during weight bearing activities. 9 Different arch configurations are an intrinsic ris...

Cardan angle rotation sequence effects on first‐metatarsophalangeal joint kinematics: implications for measuring hallux valgus deformity

“…Although the difference in joint motion between trials is notable, these results indicate that dorsiflexion and abduction should occur at the 1-MTP joint into late stance phase of gait (Figures 1 and 2). Consistent with data reported in these past gait trials [6,7], increasing amounts of dorsiflexion and abduction were expected in this study - where gait was simulated by posing the foot on a system of wedges (Figure 3). When interpreting these results, it is important to remember the participant’s foot was positioned the same for both sequences, so any difference in 1-MTP joint angles shows the effects of the rotation sequence and nothing else.…”

Multi-segment foot landing kinematics in subjects with chronic ankle instability

“…Marker data were filtered using a fourth order Butterworth low-pass filter at 15Hz, with 50 points reflected. Euler rotations (X-Y-Z, representing respectively dorsi-/plantar flexion, eversion/inversion, ab-/adduction) were used to calculate motion between the defined segments in the different planes [20]. Joint kinematics were calculated for the impact phase which was defined from touch down (TD) until maximal dorsiflexion in the ankle joint (maxDF).…”

The Role of the Midfoot in Drop Landings

“…For example, Dixon et al used the Oxford foot model to study midfoot power generation in walking (9). De Mits et al had healthy subjects walk barefoot to analyze midfoot kinematics using the Ghent model, a six-segment foot model used by physical therapists and podiatrists (10). Another study examined midfoot motion in high-and low-arched individuals during running (11).…”