A patella marker to improve hip and knee kinematics for models with functionally defined joint axes

Current practices in clinical gait analysis in Europe: A comprehensive survey-based study from the European society for movement analysis in adults and children (ESMAC) standard initiative

BACKGROUND

Clinical gait analysis (CGA) is a systematic approach to comprehensively evaluate gait patterns, quantify impairments, plan targeted interventions, and evaluate the impact of interventions. However, international standards for CGA are currently lacking, resulting in various national initiatives. Standards are important to ensure safe and effective healthcare practices and to enable evidence-based clinical decision-making, facilitating interoperability, and reimbursement under national healthcare policies. Collaborative clinical and research work between European countries would benefit from common standards.

RESEARCH OBJECTIVE

This study aimed to review the current laboratory practices for CGA in Europe.

METHODS

A comprehensive survey was conducted by the European Society for Movement Analysis in Adults and Children (ESMAC), in close collaboration with the European national societies. The survey involved 97 gait laboratories across 16 countries. The survey assessed several aspects related to CGA, including equipment used, data collection, processing, and reporting methods.

RESULTS

There was a consensus between laboratories concerning the data collected during CGA. The Conventional Gait Model (CGM) was the most used biomechanical model for calculating kinematics and kinetics. Respondents also reported the use of video recording, 3D motion capture systems, force plates, and surface electromyography. While there was a consensus on the reporting of CGA data, variations were reported in training, documentation, data preprocessing and equipment maintenance practices.

SIGNIFICANCE

The findings of this study will serve as a foundation for the development of standardized guidelines for CGA in Europe.

The effect of functional calibration methods on gait kinematics in adolescents with idiopathic rotational deformity of the femur

BACKGROUND

Due to anatomical deviations, assumptions of the conventional calibration method for gait analysis may be violated in individuals with rotational deformities of the femur. Functional calibration methods were compared with conventional methods in this group for 1) localization of the hip joint center and orientation of the knee axis, and 2) gait kinematics.

METHODS

Twenty-four adolescents with idiopathic rotational deformity of the femur underwent gait analysis and a CT scan. During standing, distance between hip joint centers and knee axis orientation were compared between calibration methods, with CT serving as reference for hip joint center estimation. Gait kinematics were compared using statistical parametric mapping.

FINDINGS

The conventional calibration method estimated the hip joint center closer to the CT reference (4±12 mm more lateral) than the functional calibration method (26 ± 20 mm more lateral). Orientation of the knee joint axis was 2.6° less internal in the functional calibration method. During gait, statistical parametric mapping revealed significantly more hip flexion, less external hip rotation during the swing phase, less knee varus-valgus motion, and larger knee flexion angles when applying the functional method.

INTERPRETATION

Functional calibration methods were less accurate in determining the hip joint center location than the conventional calibration method and resulted in a knee joint axis that was less internally rotated. Importantly, there was less knee joint angle crosstalk during gait when using the functional method. Although differences between methods on gait kinematics were within clinically acceptable limits for the sagittal plane, relatively larger differences on transversal hip kinematics may hold clinical importance.

A new marker cluster anchored to the iliotibial band improves tracking of hip and thigh axial rotations

Tracking hip and thigh axial rotation has limited accuracy due to the large soft tissue artifact. We proposed a tracking-markers cluster anchored to the prominent distal part of the iliotibial band (ITB) to improve thigh tracking. We investigated if the ITB cluster improves accuracy compared with a traditionally used thigh cluster. We also compared the hip kinematics obtained with these clusters during walking and step-down. Hip and thigh kinematics were assessed during a task of active internal-external rotation with the knee extended, in which the shank rotation is a reference due to smaller soft-tissue artifact. Errors of the hip and thigh axial rotations obtained with the thigh clusters compared to the shank cluster were computed as root-mean-square errors, which were compared by paired t-tests. The angular waveforms of this task were compared using the statistical parametric mapping (SPM). Additionally, the hip waveforms in all planes obtained with the thigh clusters were compared during walking and step-down, using Coefficients of Multiple Correlation (CMC) and SPM (α = 0.05 for all analyses). The ITB cluster errors were approximately 25 % smaller than the traditional cluster error (p < 0.001). ITB cluster errors were smaller at external rotation angles while the traditional cluster error was smaller at internal rotation angles (p < 0.001), although the clusters' waveforms were not significantly different (p ≥ 0.005). During walking and step-down, both clusters provided similar hip kinematics (CMC ≥ 0.75), but differences were observed in parts of the cycles (p ≤ 0.04). The findings suggest that the ITB cluster may be used in studies focused on hip axial rotation.