Activity-related risk factors

• Posture. It's a problem when you slouch or when you bend, twist, or reach too far. Awkward postures overwork soft tissues and joints. Any body position can also be a risk if it's held so long that muscles tense up and blood flow is reduced (static posture).

• Force. This is pressure or strain on the body. You create force when you grip or when you pull, push, or lift heavy materials. Contact force occurs when you lean or press against a hard surface or sharp edge.

• Repetition. This is doing the same task or using the same set of muscles over and over again.

• The environment. This is your surroundings, such as cold temperatures, vibration, and lighting.

• Duration. This is the length of time you're exposed to a risk factor. The longer the exposure, the higher your risk.

• Recovery time. This is the amount of time the body needs to rest after doing a repetitive task or being in an awkward posture. Recovery time becomes a risk when the time between activities isn't long enough for the body to recover.

Two risks are greater than one

The more often you're exposed to a risk factor, the more likely you are to get a WMSD. Your chance of injury also goes up greatly when risk factors are combined. For instance, frequent repetition becomes even riskier when it's combined with lots of force.