The most common fall into three groups.

  1. Sudden injuries: strains and sprains from lifting, slips and falls, fractures, crush injuries, and injuries involving machinery or vehicles.
  2. Repetitive strain built up over time: tendinitis, carpal tunnel syndrome, rotator cuff injury, low back pain from repeated lifting, and knee pain from prolonged kneeling or stair work. These often have no single moment you can point to, and they are covered.
  3. Aggravation of something pre-existing: a back, shoulder, or knee that was manageable until your job made it worse. This is frequently compensable, and people frequently do not realize it.

By body region, the most common are the low back, shoulder, knee, neck, and wrist or hand.