Comparison of the kinematics, repeatability, and reproducibility of five different multi-segment foot models

Reliability testing of an IMU-based 2-segment foot model for clinical gait analysis

BACKGROUND

The one of the most commonly used reference system for clinical gait analysis is an optical motion capture system (OMC) using a multi-segment foot model. A time- and cost-efficient alternative could be an inertial measurement unit (IMU)-based systems. However, these are limited to a single segment approach for the foot and ankle. Therefore, the current setup was modified to be based on a 2-segment foot model, allowing for a separate analysis of the hind- and midfoot. The study aimed to evaluate the reliability (inter-rater, intra-rater, and test-retest reliability) of an IMU-based 2-segment foot model.

MATERIAL AND METHODS

Twelve healthy subjects were recruited to test the inter-rater, intra-rater, and test-retest reliability of the new IMU based 2-segment foot model. Gait analysis was performed on a treadmill at a constant speed of 4 km/h. Kinematic data of the tibia/hindfoot, tibia/forefoot and hindfoot/forefoot over 100 % gait cycle were analyzed. The reliability was tested by using statistical parametric mapping (SPM) and the intraclass correlation coefficient (ICC).

RESULTS

The SPM showed no significant difference for inter-, intra-rater, and test-retest reliability, but for a small segment of tibia/forefoot dorsiflexion test-retest reliability (2.1° difference). The single standard deviation measurement error for the sagittal and transverse plane was <5° and worse for the frontal plane.

CONCLUSION

The new 2-segment foot model revealed a high inter-rater, intra-rater, and test-retest reliability. It is suitable for use in adult clinical practice. Still, comparative data to the OMC system using a multi-segment foot model are missing.

Three-dimensional gait analysis of orthopaedic common foot and ankle joint diseases

Walking is an indispensable mode of transportation for human survival. Gait is a characteristic of walking. In the clinic, patients with different diseases exhibit different gait characteristics. Gait analysis describes the specific situation of human gait abnormalities by observing and studying the kinematics and dynamics of limbs and joints during human walking and depicting the corresponding geometric curves and values. In foot and ankle diseases, gait analysis can evaluate the degree and nature of gait abnormalities in patients and provide an important basis for the diagnosis of patients' diseases, the correction of abnormal gait and related treatment methods. This article reviews the relevant literature, expounds on the clinical consensus on gait, and summarizes the gait characteristics of patients with common ankle and foot diseases. Starting from the gait characteristics of individuals with different diseases, we hope to provide support and reference for the diagnosis, treatment and rehabilitation of clinically related diseases.

Symptomatic flatfoot in cerebral palsy

PURPOSE OF REVIEW

The purpose of this review is to evaluate the current literature and best practices in the evaluation and treatment of symptomatic flatfoot in cerebral palsy.

RECENT FINDINGS

While techniques to reconstruct the neuromuscular flatfoot and reestablish bony levers have remained similar over time, the concept of surgical dosing has helped guide appropriate interventions based on the magnitude of disease and functional level of the child. Moreover, the utilization of multisegment foot modeling in motion analysis has allowed quantitative description of such deformities and their impact on gait.

SUMMARY

Future research should focus on refining operative indications and interventions with larger, multicenter, prospective cohorts to provide more robust evidence in surgical decision making. Long-term data are needed to confirm and compare efficacy of procedures. Radiographic data alone are not sufficient for describing functional foot position. Gait analysis with foot modeling and pedobarography along with patient-centered subjective outcomes will be needed in such investigations to make conclusive recommendations.

Walking Performance during Concurrent Cognitive and Motor Tasks in Individuals with Nonspecific Chronic Low Back Pain: A Case-Control Study

Background

The present study aimed to compare the effects of simultaneous cognitive and motor tasks on walking performance between individuals with nonspecific chronic low back pain (NSCLBP) and healthy controls.

Methods

A total of 20 patients with NSCLBP and 20 healthy controls participated in this study. They walked at their self-selected speed on a treadmill under 3 walking conditions in a randomized order: walking only, walking while performing a concurrent cognitive task, and walking while performing a concurrent motor task. Two-way repeated measure analysis of variance with additional post hoc comparison (Bonferroni test) was used to evaluate the effects of group and walking conditions on gait parameters.

Results

The result showed a significant main effect of the group for swing time ( P = 0.012) and double support time (P = 0.021) in those with NSCLBP compared with healthy controls. Moreover, there was a significant interaction between the group and condition for cadence ( P = 0.004) and step width variability (P = 0.016).Regarding stride length variability and stride time variability, the analysis indicated a significant effect of condition (P = 0.002 and P = 0.030, respectively). In both groups, no significant differences were observed in gait parameters between motor dual task and single walking ( P > 0.05).

Conclusion

Our findings indicated that those with NSCLBP adapted successfully to walking performance to maintain the performance of the concurrent cognitive task under the cognitive dual-task walking condition. Moreover, the present study observed no dual-task interference under the motor dual-task condition.

Ankle Kinematics Characterization in Children with Idiopathic Toe Walking: Does the Foot Model Change the Clinical Evaluation?

Idiopathic toe walking (ITW) is a gait deviation characterized by forefoot contact with the ground, sometimes observed in children, that alters ankle kinematics, possibly leading to health-related issues. When studying foot and ankle gait deviations, the adoption of a single-segment foot model entails a significant simplification of foot and ankle movement, and thus may potentially mask some important foot dynamics. Differences in ankle kinematics between single- (conventional gait model, PiG, or Davis) and multi-segment (Oxford foot model, OFM) foot models were investigated in children with ITW. Fourteen participants were enrolled in the study and underwent instrumented gait analysis. Children were asked to walk barefoot and while wearing a foot orthosis that modified the ankle movement pattern toward a more physiological one without blocking foot intrinsic motion. ITW gait abnormalities, e.g., the absence of heel rocker and the presence of anticipated forefoot rocker, were found/not found according to the foot model. Walking conditions significantly interacted with the foot model effect. Finally, the different characterization of gait abnormalities led to a different classification of ITW, with a possible impact on the clinical evaluation. Due to its closer adhesion to ankle anatomy and to its sensitivity to ITW peculiarities, OFM may be preferable for instrumented gait analysis in this population.

Foot and Ankle Motion after Tibiotalocalcaneal Arthrodesis: Comparison with Tibiotalar Arthrodesis Using a Multi-Segment Foot Model

BACKGROUND

Tibiotalocalcaneal arthrodesis is an established surgical procedure for treating patients with end-stage ankle joint arthritis and subtalar joint arthritis. Although it greatly relives pain, a major drawback is loss of range of motion. Although it is known to restrict an additional subtalar joint compared to tibiotalar arthrodesis, there is a lack of gait analysis studies comparing the two methods. This study aimed to evaluate the differences in kinematics of the foot and ankle joints between tibiotalar and tibiotalocalcaneal arthrodesis. We also compared preoperative and postoperative statuses for each surgical method.

METHODS

The study included 12 and 9 patients who underwent tibiotalar and tibiotalocalcaneal arthrodesis, respectively, and 40 healthy participants were included in the control group. The DuPont foot model was used to analyze intersegmental foot and ankle kinematics during gait.

RESULTS

Compared to controls, both tibiotalar and tibiotalocalcaneal arthrodesis resulted in slow gait speed with reduced stride length, increased step width, and decreased range of sagittal plane motion. Both fusion methods showed similar range of motion in all segments and planes following surgery. Coronal positions showed more supination of the forefoot and pronation of the hindfoot segment after each operation, particularly tibiotalocalcaneal arthrodesis. Gait after tibiotalocalcaneal arthrodesis did not significantly differ from that after tibiotalar arthrodesis, but there was a tendency of more pronation in the hindfoot segment.

CONCLUSIONS

Both fusion methods limited foot and ankle motion in similar ways. Comparing tibiotalar and tibiotalocalcaneal arthrodesis suggests that additionally fusing the subtalar joint does not cause greater movement restriction in patients. Objectively comparing tibiotalar and tibiotalocalcaneal arthrodesis will facilitate further understanding of the effect of tibiotalocalcaneal arthrodesis on movement and the value of subtalar joint motion for improved preoperative counselling.

Do different multi-segment foot models detect the same changes in kinematics when wearing foot orthoses?

Background

Different multi-segment foot models have been used to explore the effect of foot orthoses. Previous studies have compared the kinematic output of different multi-segment foot models, however, no study has explored if different multi-segment foot models detect similar kinematic changes when wearing a foot orthoses. The aim of this study was to compare the ability of two different multi-segment foot models to detect kinematic changes at the hindfoot and forefoot during the single and double support phases of gait when wearing a foot orthosis.

Methods

Foot kinematics were collected during walking from a sample of 32 individuals with and without a foot orthosis with a medial heel bar using an eight-camera motion capture system. The Oxford Foot Model (OFM) and a multi-segment foot model using the Calibrated Anatomical System Technique (CAST) were applied simultaneously. Vector field statistical analysis was used to explore the kinematic effects of a medial heel bar using the two models, and the ability of the models to detect any changes in kinematics was compared.

Results

For the hindfoot, both models showed very good agreement of the effect of the foot orthosis across all three anatomical planes during the single and double support phases. However, for the forefoot, the level of agreement between the models varied with both models showing good agreement of the effect in the coronal plane but poorer agreement in the transverse and sagittal planes.

Conclusions

This study showed that while consistency exists across both models for the hindfoot and forefoot in the coronal plane, the forefoot in the transverse and sagittal planes showed inconsistent responses to the foot orthoses. This should be considered when interpreting the efficacy of different interventions which aim to change foot biomechanics.

A functional calibration protocol for ankle plantar-dorsiflexion estimate using magnetic and inertial measurement units: Repeatability and reliability assessment

The ankle joint complex presents a tangled functional anatomy, which understanding is fundamental to effectively estimate its kinematics on the sagittal plane. Protocols based on the use of magnetic and inertial measurement units (MIMUs) currently do not take in due account this factor. To this aim, a joint coordinate system for the ankle joint complex is proposed, along with a protocol to perform its anatomical calibration using MIMUs, consisting in a combination of anatomical functional calibrations of the tibiotalar axis and static acquisitions. Protocol repeatability and reliability were tested according to the metrics proposed in Schwartz et al. (2004) involving three different operators performing the protocol three times on ten participants, undergoing instrumented gait analysis through both stereophotogrammetry and MIMUs. Instrumental reliability was evaluated comparing the MIMU-derived kinematic traces with the stereophotogrammetric ones, obtained with the same protocol, through the linear fit method. A total of 270 gait cycles were considered. Results showed that the protocol was repeatable and reliable for what concerned the operators (0.4 ± 0.4 deg and 0.8 ± 0.5 deg, respectively). Instrumental reliability analysis showed a mean RMSD of 3.0 ± 1.3 deg, a mean offset of 9.4 ± 8.4 deg and a mean linear relationship strength of R² = 0.88 ± 0.08. With due caution, the protocol can be considered both repeatable and reliable. Further studies should pay attention to the other ankle degrees of freedom as well as on the angular convention to compute them.