Development of a real time estimation method of L5S1 moments in occupational lifting

Mechanical loading of the low-back is an important risk factor for the development of low-back pain. Real-time estimation of the L5S1 joint moment (ML5S1) can give an insight to reduce mechanical loading. Model accuracy depends on sensor information, limiting the number of input variables to estimate ML5S1 increases practical feasibility, but...

Effects of a passive back exoskeleton on the mechanical loading of the low-back during symmetric lifting

Low-back pain is the number one cause of disability in the world, with mechanical loading as one of the major risk factors. Exoskeletons have been introduced in the workplace to reduce low back loading. During static forward bending, exoskeletons have been shown to reduce back muscle activity by 10% to 40%. However, effects during dynamic...

Selecting the appropriate input variables in a regression approach to estimate actively generated muscle moments around L5/S1 for exoskeleton control

Back support exoskeletons are designed to prevent work-related low-back pain by reducing mechanical loading. For actuated exoskeletons, support based on moments actively produced by the trunk muscles appears a viable approach. The moment can be estimated by a biomechanical model. However, one of the main challenges here is the feasibility of...

Biomechanical evaluation of a new passive back support exoskeleton

The number one cause of disability in the world is low-back pain, with mechanical loading as one of the major risk factors. To reduce mechanical loading, exoskeletons have been introduced in the workplace. Substantial reductions in back muscle activity were found when using the exoskeleton during static bending and manual materials handling....

The effect of control strategies for an active back-support exoskeleton on spine loading and kinematics during lifting

With mechanical loading as the main risk factor for LBP, exoskeletons (EXO)are designed to reduce the load on the back by taking over part of the moment normally generated by back muscles. The present study investigated the effect of an active exoskeleton, controlled using three different control modes (INCLINATION, EMG & HYBRID), on spinal...

Effects of a passive exoskeleton on the mechanical loading of the low back in static holding tasks

With mechanical loading as the main risk factor for LBP in mind, exoskeletons are designed to reduce the load on the back by taking over a part of the required moment. The present study assessed the effect of a passive exoskeleton on back and abdominal muscle activation, hip and lumbar flexion and on the contribution of both the human and the...

Interaction of ultrasonic waves with partially-closed cracks in concrete structures

Interaction of ultrasonic waves with partially-closed surface-breaking cracks in concrete structures has been studied. Measurements have been conducted on a reinforced concrete beam containing various mechanical-load-induced cracks and compared with the baseline measurements at those locations. Influence of crack width, incident angle of waves...

Thermo-mechanical challenges for quantum devices

In the last few years Technical University of Delft, under leadership of Prof.dr.ir. Leo Kouwenhoven, has developed several successful concepts for quantum devices that are suitable for quantum computing and quantum communication. From a quantum research point of view we are still in a very fundamental state, several practical issues already...

The contribution of load magnitude and number of load cycles to cumulative low-back load estimations: A study based on in-vitro compression data

Background: Cumulative low-back load is suggested to be associated with low back pain, possibly due to (micro-)fractures of spinal segments. Based on available in vitro data it can be assumed that, in order to predict spine segment failure from cumulative compressive loading, load magnitude should be weighted with an exponent higher than one,...

Cyclic mechanical stretch reduces myofibroblast differentiation of primary lung fibroblasts

In lung fibrosis tissue architecture and function is severely hampered by myofibroblasts due to excessive deposition of extracellular matrix and tissue contraction. Myofibroblasts differentiate from fibroblasts under the influence of transforming growth factor (TGF) β₁ but this process is also controlled mechanically by cytoskeletal...