which of these is not a personal risk factor that can cause back injuries?
['Aging. Over time, wear and tear on the spine that may result in conditions (e.g., disc degeneration, spinal stenosis) that produce neck and back pain. ... ', 'Genetics. ... ', 'Occupational hazards. ... ', 'Sedentary lifestyle. ... ', 'Excess weight. ... ', 'Poor posture. ... ', 'Pregnancy. ... ', 'Smoking.']