A novel hand-arm system (HASy), being developed in DLR as an anthropomorphic system, requires as an input parameter the realistic instantaneous joint stiffness of human upper limb in different postures and movements. Because muscles in our musculokeletal system are the active component (actuator), joint stiffness is driven by muscle stiffness. In this thesis, the theoretical fundamentals in ext...

the joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. therefore, the bending moment act...

Introduction: Although, the effect of direct intra-articular injection of bone marrow stem cells (BMSCs) on the repair of articular cartilage and the effect of Elaeagnus angustifolia extract on pain relief in patients with osteoarthritis have been investigated, no studies has been conducted to compare the effects of these two therapeutic methods on the mechanical properties of articular cartila...

Stiffness properties of the musculo-skeletal system can be controlled by regulating muscle activation and neural feedback gain. To understand the regulation of multijoint stiffness, we examined the relationship between human arm joint stiffness and muscle activation during static force control in the horizontal plane by means of surface electromyographic (EMG) studies. Subjects were asked to pr...

Human arm viscoelasticity is important in stabilizing posture, movement, and in interacting with objects. Viscoelastic spatial characteristics are usually indexed by the size, shape, and orientation of a hand stiffness ellipse. It is well known that arm posture is a dominant factor in determining the properties of the stiffness ellipse. However, it is still unclear how much joint stiffness can ...

According to the wide application of segmental lining in mechanized tunneling, recognizing the behavior of segmental lining joints is important in tunnels designing. In the structural analysis of the tunnel segmental lining, segmental joints can be considered as elastic joints, and their stiffness characteristics are affected by the rotational, shear, and axial stiffness. The purpose of this wo...

This work is focused on the analysis of manipulators with both joint and link flexibility. Due to the different order of joint and link stiffness, the full-order nonlinear system can be decomposed into different time-scale subsystems, namely, slow subsystem, mid-speed subsystem, and fast subsystem. It is shown that when the link stiffness is much greater than joint stiffness 01when the two kind...

(i) Subjective rating a joint is moved through its range of motion by a tester who then grades the joint as ‘stiff’, ‘normal’ or ‘hypermobile’. (ii) Maximum range of motion (ROM) measured using goniometry and ruler scales. (iii) Joint stiffness – joint displacement and force applied are taken into account to calculate joint stiffness. In the foot, only the stiffness for the first ray has been r...

Background: People with knee osteoarthritis have a low quality of life due to joint pain and stiffness that severely limits their daily activities.  This study aims to investigate the impact of self-acupressure on the pain, joint stiffness and physical functioning of patients with osteoarthritis. Methods: This randomized clinical trial was conducted on 78 patients aged 50 to 70 years with knee...