Quantifying workload using nonlinear dynamical measures of biomechanical parameters during cycling on a roller trainer.

The aim of the present study was to determine the effectiveness of nonlinear parameters in distinguishing individual workload in cycling by using bike-integrated sensor data. The investigation focused on two nonlinear parameters: The ML1, which analyzes the geometric median in phase space, and the maximum Lyapunov exponent as nonlinear measure of local system stability. We investigated two hypothesis: 1.

Comparison of statistical models for characterizing continuous differences between two biomechanical measurement systems.

Most biomechanical processes are continuous in nature. Measurement systems record this continuous behavior as curve data, which is often treated inappropriately in validation studies. The current paper compares different statistical models for analyzing the agreement of curves from two measurement systems.

Effects of an active hand exoskeleton on forearm muscle activity in industrial assembly grips.

Background: The Bioservo Ironhand® is a commercially available active hand exoskeleton for reducing grip-induced stress.

Objectives: The study aimed at quantifying the effect of the Ironhand® exoskeleton on the myoelectric muscle activity of forearm flexor and extensor muscles in three relevant assembly grip tasks: 2-Finger-grip (2Finger), 5-Finger-grip (5Finger) and Full grip (FullGrip).

Methods: Twenty-two subjects were tested in three different exoskeleton conditions for each grip task (overall 3×3×10 = 90 repetitions in randomized order): Exoskeleton off (Off), Exoskeleton on, "locking tendency" 0% (On_LT0), and Exoskeleton on, "locking tendency" 85% (On_LT85).

Icy road ahead-rapid adjustments of gaze-gait interactions during perturbed naturalistic walking.

Most humans can walk effortlessly across uniform terrain even when they do not pay much attention to it. However, most natural terrain is far from uniform, and we need visual information to maintain stable gait. Recent advances in mobile eye-tracking technology have made it possible to study, in natural environments, how terrain affects gaze and thus the sampling of visual information.

Phase space methods for non-linear analysis of pedalling forces in cycling.

Introduction: From the perspective of dynamic systems theory, stability and variability of biological signals are both understood as a functional adaptation to variable environmental conditions. In the present study, we examined whether this theoretical perspective is applicable to the pedalling movement in cycling. Non-linear measures were applied to analyse pedalling forces with varying levels of subjective load.

Validation of an inertial measurement unit for the quantification of rearfoot kinematics during running.

Background: The popular protocol used to study running motion suffers from problems that lead to a limited ability to generalize the obtained results. Inertial measurement units (IMU) appear to be promising in increasing ecological validity of the collected data. However, quantifying running kinematics utilizing IMU signals is complex and potentially affected by several well-established and less well-known errors.