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The Forget about ergonomics in chair design? Focus on aesthetics and comfort!

Chair users have difficulties distinguishing between chairs  of various  ergonomics quality. Many ergonomics features that are  alleged to  relieve discomfort in sitting are indistinguishable because  they can't  be perceived.  this is often   thanks to  poor proprioceptive feedback from ligaments, joints  and therefore the  spine. The joints are relatively insensitive to small changes in angle,  and therefore the  spine cannot sense differences in pressure  thanks to  different body postures. Aesthetics features on  the opposite  hand, and features  associated with comfort and relaxation, are easier to perceive and differentiate. A study of ergonomics chairs verified that users could distinguish between parameters that relate to aesthetics  and luxury , but had difficulty in distinguishing between ergonomics features.  within the  end aesthetics  could also be  more important than ergonomics—at least to the customer who  are going to be  guided more by aesthetics than longer-term ergonomic factors.

[creatyourchair-blog]

The Wheelchair Propulsion Biomechanics

The aim of  this text  is  to supply the reader with a state-of-the-art review on biomechanics in hand rim wheelchair propulsion, with special attention to sport-specific implications. Biomechanical studies in wheelchair sports mainly aim at optimising sport performance or preventing sport injuries. The sports performance optimisation question has been approached from an ergonomic,  also  as a skill proficiency perspective. Sports medical issues  are  addressed in wheelchair sports mainly  due to  the extremely high prevalence of repetitive strain injuries  like  shoulder impingement and carpal tunnel syndrome. Sports performance  also  as sports medical reflections are made throughout the review. Insight  within the  underlying musculoskeletal mechanisms of hand rim wheelchair propulsion has been achieved through  a mixture of experimental data collection under realistic conditions, with a more fundamental mathematical modelling approach. Through a synchronised analysis of the movement pattern, force generation pattern and muscular activity pattern, insight has been gained  within the  hand rim wheelchair propulsion dynamics  of individuals with a disability, varying in level of physical activity and functional potential. The limiting environment of a laboratory, however, has hampered the drawing of sound conclusions. Through mathematical modelling, simulation and optimisation (minimising injury and maximising performance), insight  within the  underlying musculoskeletal mechanisms during wheelchair propulsion is sought.  the excess  value of inverse and forward dynamic simulation of hand rim stroke dynamics is addressed.

[creatyourchair-blog]

A Wheel chair

A mechanism for the transport of an object across relatively level surfaces  also   on  ascend and descend stairways. The mechanism is described particularly with  reference to  a wheel chair for handicapped persons and is  given  a frame and a pair of support wheels on  all sides  of the frame. A climbing chain with lugs is  related to each wheel on the frame; these chains being inclined at an angle providing a desired lifting height. The wheel chair is either powered by the occupant or by electrical or other corresponding power means. Appropriate sensing means on the frame ascertain a nonlevel condition in pitch or yaw during ascent or descent of  the steps  whereby corrections are made  within the  driving means  such   A level  orientation is re-established. Braking is provided by appropriate gearing whereby  a disruption  of the driving power holds the climbing chains in their current position. In one embodiment, the mechanism is  given  means for selectively varying the relative rotational speed of  the varied  climbing chains to facilitate the substantially simultaneous loading  of every  climbing chain. Specific embodiments of drive trains and climbing chains are described.