While a simple chair has a structure that is very intuitive to adapt to, sitting (or even semi-standing) humans have a tendency to shape themselves in innovative ways that chair manufacturers might not have foreseen.
Some of the ones that caught my eye include a continuation of an activity, positioning the chair in such a way that another use is satisfied or a user alignment orthogonal to the intended one. As a continuation of an activity, students might carry a bag and in a hurry completely nullify the back-rest that the chair provides, by resting the bag and sitting on the edge themselves. Repositioning the chair so that a user can stretch a muscle or rest a knee while deeply engrossed in study or a standing conversation respectively are more cases in which a seat’s intention starts to become less rigid in how it must be used. While the intended back-rest is for the back, sometimes the lack of an arm rest allow the user to rest sideways on a back-rest allowing the muscles to be stimulated in that position.
Here are some of the images:
1. Continuation of the preceding activity
2. Repositioning the chair (stretch ankle and rest knee)
3. Orthogonal