Sentence examples for without a backrest from inspiring English sources
The responses at the seat have been compared with those measured previously on a seat without a backrest.
WBV-exposures are often linked with forced postures as prolonged sitting, bent forward sitting, or sitting without a backrest.
Compared to sitting without a backrest, sitting with a rigid vertical backrest increased the resonance frequency of the fore-and-aft cross-axis transmissibility of the seat pan cushion and increased the transmissibility at resonance.
Twelve male subjects used the method of magnitude estimation to judge the discomfort produced by sinusoidal oscillations in the pitch and fore-and-aft axes at 10 frequencies between 0.2 and 1.6 Hz, while seated with and without a backrest.
These changes were greater than the 0.9-Hz increase in resonance frequency between sitting without a backrest and sitting with a reclined rigid backrest, and greater than the 1.0-Hz reduction in resonance frequency when the magnitude of vibration increased from 0.5 to 1.5 m s−2 rms.
At frequencies greater than about 0.4 Hz with a backrest, and at frequencies greater than about 0.8 Hz without a backrest, fore-and-aft acceleration in the plane of the seat arising from pitch oscillation caused greater discomfort than the same acceleration produced by fore-and-aft oscillation.
In the second experiment, six subjects were exposed to three vibration magnitudes (0.125, 0.25, 0.625 m s−2 rms) in the average thigh contact posture, both with and without a rigid backrest.
The dynamic interaction between the human back and a backrest is complex: the forces at the back backrest interface depend on the dynamic characteristics of both the back and the backrest, which vary with location over the backrest.
3. The Lucy chair by Vecta has a backrest made of translucent Pellethane, a surprisingly comfortable rubbery material.
A pillow is taped to the wall as a backrest, and another pillow makes the bench softer to sit on.
The top corners of each modular piece tilt inward, creating a backrest that supports different seating positions.
