Is the Språng Chair height adjustable?
YES! The chair can accommodate anyone from 4'9" to 6’7” by a combination of over-inflating or under-inflating the exercise ball, removing the casters, or add a height extension riser kit.
• Seat Height Adjustment: 13″ to 20.5″
• Seat Depth Adjustment: 10” to 18”
• Seat Width: 18.5”
• Lumbar Support Width: 15.5″
• Weight Limit: 300 lbs
What is the weight limit?
I just confirmed with the factory, we are increasing the capacity of the ball to support over 400 lbs; and because the casters are engineered with a U-saddle bracket, they are significantly higher load-bearing than a comparable stem caster.
Do you have research to support your claims?
The quickest reference is the current Wikipedia page on Active Sitting: https://en.wikipedia.org/wiki/Active_sitting
Ergonomics: Benefits of Active Sitting for the Able-bodied
The field of ergonomics, in particular that of office furniture, now offers various active sitting products that enable different kinds of movement: forward and backward, lateral (side to side), 360 degree wobble, etc. It is important to note that the ergonomic research also indicates that - although movement is necessary - it is not enough. All movements are not the same; there are movements to be avoided. For example, movement that alternates between different awkward sitting postures that repeatedly load the same joints will provide little benefit. http://www.humanics-es.com/ergonomics_movement.htm#ergonomicpostures
The benefits of active sitting are understood to occur with movements through a graded range of centered and symmetrical postures. The active and controlled postural positions in sitting are believed to activate and strengthen muscles in the back and core area, [http://journals.lww.com/spinejournal/pages/articleviewer.aspx?year=2009&issue=03150&article=00021&type=abstract] to relieve the static loads acting on joints, ligaments, and tendons, and to promote circulation for elimination of waste products. Thus, a dynamic, ergonomic sitting position is believed to lead to improved posture, core stability, and circulation.
Although extensive research in the field of ergonomics and active sitting is yet to become widely available, the logical benefits are easily extrapolated. The pelvis is tilted more forward in active sitting, and this pelvic position situates the spine for proper alignment and postural health. [http://www.tandfonline.com/doi/abs/10.1080/00140139.2010.544765]
Since the individual is able to move in a controlled manner during active sitting, the body will strengthen postural muscles to maintain balance. This conditioning of the core muscles of the spine and trunk may significantly aid in preventing back pain. In turn, it is understood that movement lubricates and nourishes the spinal joints and intervertebral discs, keeping skeletal joints flexible and healthy. [http://www.sciencedirect.com/science/article/pii/S0003687099000307]
Many age-related changes in spinal joints are likely due to a lack of proper nourishment and motion. With postural stabilization in sitting and reaching, the leg and calf muscles are activated.[http://www.gaitposture.com/article/S0966-6362(99)00026-0/abstract]
When the muscles of the lower extremities work lightly, as during active sitting, the resulting regular pumping action stimulates the return of lymphatic fluid, and minimizes lower leg edema and swollen ankles.[https://www.ncbi.nlm.nih.gov/pubmed/10755663]
Since movement allows blood to flow freely from the lower extremities, this improved circulation can reduce the risk of the development of deep vein thrombosis (DVT) while seated. Meanwhile, overall bodily movement may "shake out" muscle tension and stress that can build up in the neck, shoulders, or jaw during prolonged sitting postures. It is even thought that movement while sitting might improve focus and alertness because of the sensory and vestibular input.
What About Standing Desks?
“Standing all day isn’t the answer...that’s where we were 100 years ago, and we needed to develop chairs to prevent curvature of the spine, backaches, and varicose veins.”
~Alan Hedge, Director, Human Factors and Ergonomics Laboratory, Cornell University
Do the casters lock?
Yes! The two front casters lock.
Is assembly required?
Yes, but don't worry, it's not difficult to assemble.
And we'll post a video of the chair being assembled so you can follow along.
How long will my order take?
Our chairs are made by hand by artisans and not in a factory. Therefore your order will ship out within approximately 2 weeks.