Tendinitis, which is sometimes referred to as "tendonitis" and is a condition characterized by irritation or inflammation of a tendon, is usually caused by repetitive motion or minor impact on the area that is affected, although some instances of the condition are caused by serious injuries. Normal everyday activities that can be to blame for causing tendinitis include raking, gardening, carpentry, shoveling, cleaning, painting, scrubbing, golf, tennis, skiing, pitching and throwing, according to WebMD.
WebMD notes that incorrect posture while working at home or elsewhere, as well as poor conditioning and stretching before exercise or when participating in sports, increases the occurrence of tendinitis. Conditions that put stress on soft tissue structures, such as poorly placed joints or bones, or legs that are of different lengths, can also be a precursor to tendinitis. In addition, those with thyroid disorders, psoriatic arthritis, gout or rheumatoid arthritis are also at enhanced risk of developing the condition.
Although anyone of any age is susceptible to developing tendinitis, it is more common in the adult population and in people who are 40 years of age or older, since tendons in aging people are less capable of tolerating stress, tear easier and are less elastic.