Worker sickness can be a major drag on productivity, forcing projects to be late and increasing costs. Where mobile plant is used, sickness means these machines are sitting idle.
A construction project using mobile plant can go on for months, depending on the scope. Using mobile plant often exposes the operator to excessive vibration, which can contribute to the development of back pain through a phenomenon known as whole-body vibration (WBV). This occurs when the entire body is exposed to mechanical oscillations or vibrations, typically transmitted through vehicles, machinery, or equipment. While the pain can also manifest itself in the limbs, pain in the back is the most debilitating.
It is one of the human factors outlined when you learn to drive a forklift or other type of mobile plant such as an excavator or wheeled loader. Off-road forklifts, bulldozers and small tracked excavators are particularly prone to this type of vibration because they don’t have conventional suspension or large pneumatic wheels to absorb the undulations of the ground.
Here are some ways in which excessive vibration may contribute to back pain:
- Muscle Fatigue and Microtrauma:
- Prolonged exposure to vibrations can lead to muscle fatigue and microtrauma in the muscles of the back. The continuous contraction and relaxation of muscles in response to vibrations can result in overuse, leading to strain and potential damage.
- Spinal Compression:
- Vibration can cause compression of the spine. As the body vibrates, the spine experiences repetitive loading, which may lead to compression of the intervertebral discs. Over time, this compression can contribute to disc degeneration and increase the risk of back pain.
- Changes in Posture:
- Vibrations can induce postural changes as the body attempts to absorb and dampen the impact of the mechanical oscillations. Prolonged exposure to altered postures can strain the muscles and ligaments of the back, leading to discomfort and pain. Forklift operators are often sitting with poor posture as the operator is forced to look upwards at the load being picked or placed.
- Reduced Blood Flow and Oxygenation:
- Vibration may impair blood flow to the muscles and tissues of the back. Reduced blood flow can limit the delivery of oxygen and nutrients to the muscles, potentially leading to muscle stiffness, inflammation, and pain. Sitting in one place for a long period of time operating a machine also makes for sluggish circulation. This can be particularly problematic in large excavators where the operator is simply loading bucket after bucket of materials without the opportunity to jump off and get some blood flow back into the legs.
- Activation of Pain Receptors:
- Vibrations can stimulate pain receptors in the back, triggering a pain response. The continuous activation of these receptors can lead to persistent discomfort and contribute to the perception of back pain.
- Vibration Frequency and Duration:
- The frequency and duration of exposure to vibrations play a crucial role. High-frequency vibrations are more likely to transmit harmful energy to the body, increasing the risk of musculoskeletal issues. Prolonged exposure amplifies the negative effects.
- Individual Susceptibility:
- Individual susceptibility varies, and some people may be more prone to experiencing back pain due to excessive vibration. Factors such as age, pre-existing musculoskeletal conditions, and overall health can influence susceptibility. Operators and drivers who are physically fit are more likely to be able to absorb the stresses of the day’s work without the muscles fatiguing so quickly.
It’s important to note that the relationship between excessive vibration and back pain is complex, and multiple factors may contribute to the development of discomfort.
To mitigate it, drivers and operators can try:
- Ergonomic adjustments – ensuring that the seat is in the right place, and that posture is correct
- Regular breaks
- Proper seating (e.g. hydraulic or sprung seating)
- Vibration mitigating gloves
- Strengthening exercises
It’s best to catch back pain early as it is unlikely to improve unless the inputs to the back pain are changed. It’s advisable to consult with a healthcare professional such as a sports physiotherapist or doctor, or a personal trainer for a comprehensive evaluation and appropriate management.