What do refrences points have to do with this phenomenon ?

Birth orgraduate orschool

Gravitational force i believe

Continuation of the question.; he indicates that he has had this pain before it. which of the following would be the best way to assess his current condition.  answer;   the best way to assess his current condition would be asking him to compare the current pain to the last time he had it.back pain, especially the lower back pain is a common problem that affects most people at some point.  symptoms include; numbness or tingling in one's genitals or buttocks arealoss of bladder or bowel controlfeeling unwell with your back pain such as a fever or significant sweating that wakes one from sleep. among other symptoms.

Heterogeneity; preferential selection of particular sites