Lower extremity neuromuscular fatigue purportedly increases anterior cruciate ligament (ACL) injury risk through promotion of extreme landing mechanics. However, the impact of fatigue on muscle groups critical to the landing strategy remains unclear. This study examined the effects of isolated hip rotator and triceps surae fatigue on lower extremity landing biomechanics. Sixteen healthy females...

Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used f...

In present work, the heart rate variability (HRV) characteristics, calculated by sample entropy (SampEn), were used to analyze the driving fatigue state at successive driving stages. Combined with the relative power spectrum ratio β/(θ + α), subjective questionnaire, and brain network parameters of electroencephalogram (EEG) signals, the relationships between the different characteristics for d...

Acoustic emission (AE) supplies information on the fracture behavior of different materials. In this study, AE activity was recorded in metal coupons with a V-shape notch, which were loaded in fatigue until final failure. AE parameters exhibit a sharp increase approximately 1000 cycles before final failure. The use of AE parameters is discussed both in terms of characterization of the damage me...

This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants (20 stroke patients, 20 age-matched healthy participants) were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exerc...

The fatigue life of tubular joints commonly found in offshore industry is not only dependent on the value of Hot-spot stress (HSS), but is also significantly influenced by the through-the-thickness stress distribution characterized by the degree of bending (DoB). The determination of DoB values in a tubular joint is essential for improving the accuracy of fatigue life estimation using the stres...

In this study the torque output of intermittently stimulated paralyzed human knee extensor muscles during imposed isokinetic cyclical lower leg movements was investigated in four paraplegic subjects. During prolonged (10 min) experiments the influence of knee angular velocity and stimulation parameters on fatigue-induced torque decline was studied. Pulse width and amplitude were set to obtain m...

The goal of this study is to investigate the influence of fatigue on Steady State Visual Evoked Potential (SSVEP) during virtual wheelchair navigation. For this purpose, an experimental environment was set based on modifiable parameters (luminosity, number of obstacles and obstacles velocities). A correlation study between SSVEP and fatigue ratings was conducted by the mean of spectral analysis...

Muscle fatigue is a common experience in daily life. Many authors have defined it as the incapacity to maintain the required or expected force, and therefore, force, power and torque recordings have been used as direct measurements of muscle fatigue. In addition, the measurement of these variables combined with the measurement of surface electromyography (sEMG) recordings (which can be measured...

BACKGROUND The flexion-relaxation phenomenon (FRP) is defined by reduced lumbar erector spinae (ES) muscle myoelectric activity during full trunk flexion. The objectives of this study were to quantify the effect of hip and back extensor muscle fatigue on FRP parameters and lumbopelvic kinematics. METHODS Twenty-seven healthy adults performed flexion-extension tasks under 4 different experimen...