Recently, an Air Canada flight made an emergency landing after severe turbulence caused injuries to numerous passengers. Turbulence cannot always be predicted nor injuries prevented. Many aspects can cause turbulence including:
Atmospheric Pressure
Jet Streams
Cold or Warm Weather Fronts
Air Movement Not Seen

According to statistics, most turbulence happens when aircrafts reach over 30,000 feet, and coming into any of the above can cause the aircraft to shake violently. Although aircrafts are built to withstand turbulence, passengers who fail to wear their seatbelts when required are at more risk of injury. The only evident way for pilots to currently avoid turbulence is by pilot reports. Therefore, if another aircraft has recently flown the same path and encountered turbulence, they report it to Air Traffic Control. At present, new, automated reports are making their way to pilots as more aircrafts are being equipped with sensors that record and report weather and turbulence. However, when boarding a flight, is it important to remember to take the advice of the cabin crew should you encounter turbulence in-flight.