Gait Biomechanics

Changes in Gait Biomechanics Between Level and Downhill Walking Do Not Differ Between Those With Anterior Cruciate Ligament Reconstruction and Controls

Conflicting evidence exists regarding the presence of aberrant gait biomechanics more than one-year following anterior cruciate ligament reconstruction (ACLR). Overground walking may not elucidate differences in those further removed from surgery due to the unexacting nature of the task. Quadriceps dysfunction is common post-ACLR and contributes to aberrant gait biomechanics, thus downhill walking may exacerbate differences as this task places greater demands on the quadriceps. Purpose: To compare gait biomechanics between individuals with ACLR and healthy controls during level and downhill walking conditions. Methods: 24 individuals more than 1-year removed from ACLR and 24 healthy controls completed both level and downhill (10 degree grade) gait biomechanics assessments on an instrumented split-belt treadmill at their preferred walking speed. Peak variables were evaluated over the first 50% of stance including the vertical ground reaction force, internal knee extension and abduction moments and knee flexion angle. Moments were normalized to %body weight*height (%BW*Ht) and vGRF was normalized to %body weight. Dependent variables were compared across groups and conditions via two-way repeated measures ANCOVAs controlling for gait speed. Results: There were no significant condition*group interaction effects nor group main effects for any outcomes. However, there were significant condition increases in knee extension moment (P=0.020) and knee flexion angle (P=0.018) from level to downhill. Conclusions: Downhill walking necessitates larger knee extension moments and knee flexion angle compared to level gait. Our results suggest that changes in gait biomechanics between level and downhill conditions do not differ between individuals with ACLR >1 year post-reconstruction and controls.
Listed In: Biomechanics, Gait, Orthopedic Research

Musculoskeletal Modeling as a Tool for Biomechanical Analysis of Normal and Pathological Gait

In this work, a 3D lower limb musculoskeletal model and simulation of multiple sclerosis disease is presented. The Model was developed using the Musculoskeletal Modeling Software (MSMS), MSMS has the advantage that the model can be exported directly to Simulink allowing us to generate Functional Electrical Stimulation (FES) and evaluate different injuries. From the simulations, is possible to obtain the joint range of motion, joint torque, muscle-tendon length, force and moment arm, this is important not only to perform biomechanical analysis but also to design exoskeleton robots for rehabilitation and to generate reference trajectories for control purposes. In order to validate the results, a study case of a normal and pathological gait is presented, then, the results are compared with the literature and with real data obtained from a low cost, and a professional gait capture system.
Listed In: Biomechanical Engineering, Biomechanics, Gait

The Influence of Body Mass Index and Sex on Frontal and Sagittal Plane Joint Moments During Walking.

Obesity and female sex are considered independent risk factors for the development of knee osteoarthritis (KOA) which may be due to aberrant gait biomechanics. Few data exist on the interaction of obesity and female sex despite their independent influence on KOA risk. The purpose of this study was to examine the influence of sex and BMI on knee joint sagittal and frontal plane gait mechanics. Dependent variables included the knee flexion moment (KFM) and first peak knee adduction moment (KAM1). Gait biomechanics were assessed in 42 obese and 39 normal weight participants that were matched on age and sex. Kinematic and kinetic data were sampled using a 9-camera Qualisys system and 2 AMTI force-plates. Participants completed walking trials in laboratory standard neutral-cushion footwear at self-selected speed and the external KFM and KAM1 during the first 50% of stance was extracted and normalized to a product of bodyweight (N) and height (m). A 2 (BMI) by 2 (Sex) analysis of co-variance (α=0.05) was used to examine dependent variables with gait speed as a covariate. The BMI by sex interaction was not significant for KFM (p=0.073) or KAM1 (p=0.703). A main effect was observed for sex and females exhibited smaller KFM (p=0.05) and greater KAM1 (p=0.004) compared to males. No differences were found in normalized knee moments between BMI groups. Regardless of BMI, females exhibited aberrant gait mechanics that are indicative of KOA progression. Further studies are needed examining the influence of altered gait in young, healthy females on knee cartilage morphology.
Listed In: Biomechanics, Gait