SIAT-WEXv2: A Wearable Exoskeleton for Reducing Lumbar Load during Lifting Tasks

Figure 3

(a) Schematic diagram of the principle of exoskeleton assistance. (b) Mechanical model of exoskeleton assistance. The orientation angle of the torso with respect to the direction of gravity, defined as zero corresponding to upright positions and positive for forward bending; is the angle of users’ lumbar motion; F_M is the contraction force developed by the spinal muscles; R_C is the compression on the lumbar disc, represented by joint reaction force along the torso; W_T and W_L are the masses of the torso and the external load, respectively; W_X is the mass of ALE; d_M is the distance between the rotation joint and the line of action of the muscles; d_T is the distance of the centre of mass of the torso from the rotational joint; d_L is the constant distance of the centre of mass of the load from that of the torso; represents assistive force.

(a)

(b)