Which physical risk factor refers to how many times a person repeats a given exertion within a given period of time?

Which physical risk factor refers to how many times a person repeats a given exertion within a given period of time?

• A. Duration
• B. Frequency
• C. Intensity
• D. Contact Stresses

Answer: (B)

The key idea here is how often the body is subjected to the same exertion over a period of time. That repetition rate is called frequency. When you repeat a task many times, your muscles, joints, and nervous system accumulate fatigue and microtrauma as a result of those cycles, so higher frequency means greater cumulative load over the same time span. Duration describes how long the activity lasts in total, not how often it’s repeated. Intensity is how hard each exertion is—how much effort or force is required per repetition. Contact stresses refer to the forces transmitted at contact points, like the hands on a tool or feet on the floor, which are specific load factors but not about repetition rate. For example, lifting a box 20 times per minute for two hours has a high frequency, increasing cumulative strain even if each lift isn’t extremely heavy. If you kept the same number of lifts per minute but shortened the session, the total exposure decreases because the duration is shorter. If you increase the effort per lift (intensity) but keep frequency the same, the per-repetition load rises, changing the risk profile in a different way.

The key idea here is how often the body is subjected to the same exertion over a period of time. That repetition rate is called frequency. When you repeat a task many times, your muscles, joints, and nervous system accumulate fatigue and microtrauma as a result of those cycles, so higher frequency means greater cumulative load over the same time span.

Duration describes how long the activity lasts in total, not how often it’s repeated. Intensity is how hard each exertion is—how much effort or force is required per repetition. Contact stresses refer to the forces transmitted at contact points, like the hands on a tool or feet on the floor, which are specific load factors but not about repetition rate.

For example, lifting a box 20 times per minute for two hours has a high frequency, increasing cumulative strain even if each lift isn’t extremely heavy. If you kept the same number of lifts per minute but shortened the session, the total exposure decreases because the duration is shorter. If you increase the effort per lift (intensity) but keep frequency the same, the per-repetition load rises, changing the risk profile in a different way.