Analysis of ebike dynamics and cyclists' anxiety levels and interactions with road vehicles that influence safety.

The significance of commuting with ebikes as an integral part of the urban mobility of the future can no longer be ignored. The real and perceived hazards of cycling in urban areas and sharing roads with other motorized vehicles have been identified as a major barrier to wider adoption of ebikes. The objective of this study is to investigate parameters that affect the anxiety level of cyclists, which influences their safety and interaction with other road users.

A comparison of knee joint moments during high flexion squatting and kneeling postures in healthy individuals.

Background: Deep knee bending has been reported as an occupational hazard to workers who have to adopt such postures. High knee joint moments have been associated with knee osteoarthritis initiation and progression.

Objective: This study aimed to compare four high knee flexion postures (dorsiflexed and plantarflexed kneeling, and flat-foot and heels-up squatting) to determine which one results in lower knee joint flexion and ab/adduction moments.

Effects of Knee Savers on the quadriceps muscle activation across deep knee bending postures.

Workers who kneel or squat frequently are at a high risk of developing knee pathologies. Knee Savers are wedge-shaped pads, worn on the lower calf by baseball catchers that aim to reduce this risk. This study examined how Knee Savers change the bilateral quadriceps muscle activity during dorsiflexed kneeling, and heels-up and flat-foot squatting.

Customized surface-guided knee implant: Contact analysis and experimental test.

Contact pressure and stresses on the articulating surface of the tibial component of a total knee replacement are directly related to the joint contact forces and the contact area. These stresses can result in wear and fatigue damage of the ultra-high-molecular-weight polyethylene. Therefore, conducting stress analysis on a newly designed surface-guided knee implant is necessary to evaluate the design with respect to the polyethylene wear.

The influence of geometric design variables on the kinematic performance of a surface-guided total knee replacement.

Objective: Tibiofemoral geometries in a total knee replacement (TKR) affect the performance of an implant during activities of daily living. The specially shaped components of a surface-guided TKR aim to control the tibiofemoral motion, such that a normal pattern of motion is achieved, even at high flexion angles. The purpose of this study was to assess the influence of the design parameters on the kinematic behavior of such an implant.

Kinematic behavior of a customized surface-guided knee implant during simulated knee-bending.

Different designs of total knee replacements (TKRs) aim to enhance the satisfaction of the patients by providing close to normal kinematics. In the surface-guided TKRs, the guidance of the motion in a normal pattern should be achieved through specially shaped articulating geometries. This study used virtual simulation along with a load-controlled knee wear simulator to evaluate the kinematic performance of a customized surface-guided TKR under weight-bearing conditions of lunging and squatting activities.

Design and virtual evaluation of a customized surface-guided knee implant.

Although total knee arthroplasty is generally a successful operation, many studies have shown that it results in significant alterations in the kinematics of the joint, which cause limitations in performing the activities of daily living. This study aimed to define the design features for a customized surface-guided total knee replacement and to evaluate the kinematic outcomes. Magnetic resonance imaging data of the knee joint are used to generate the design features as they relate to the functionality of the implant.

Design optimization of an above-knee prosthesis based on the kinematics of gait.

A dynamic model of an above-knee prosthesis during the complete gait cycle was developed. The model was based on a two-dimensional multi-body mechanical system and included a hydraulic and an elastic controller for the knee and a kinematical driver controller for the prosthetic ankle. The equations of motion were driven using Lagrange method.