Hi-lo’s are standard equipment used in manufacturing. With the large size and weight of various objects within the facility, hi-lo’s are essential to keeping production moving throughout the day. There is a misconception that driving a hi-lo all day is easy and won’t lead to injury. This isn’t always the case. Many times hi-lo drivers will seek treatment for neck and/or back symptoms but do not understand how sitting for prolonged periods on a hi-lo could lead to symptoms. Prolonged sitting with repetitive motions place increased stress on the low back and contributes to muscle tightness in the hip flexors and hamstrings.
Prolonged sitting, driving in reverse, which causes sustained repetitive single direction torso rotation, as well as job related stress will likely lead to symptom onset. These symptoms will generally manifest themselves over time rather than after a sudden single episode. This increases the likelihood that employees won’t seek treatment early in symptom onset. Symptoms may be mild at first but eventually increase to the point where performing their job becomes difficult. Hi-lo design can also be a contributor to musculoskeletal disorders (MSDs). Although sit down hi-lo’s are more common, stand up hi-los can also contribute to MSDs. Although standing places less stress on the back compared to sitting, poor standing posture can result in low back soreness. Repetitive motions of the neck are also a factor when looking over head and behind while driving in reverse.
Its not hard to see the common contributing factors from driving a hi-lo. The good news is, there are several activities and other measures that can be taken to help prevent and manage discomfort:
1. Posture– When sitting on the hi-lo, maintaining a neutral upright posture can help to decrease stress on the spine, thus decreasing muscle fatigue and soreness. Using a lumbar roll placed between the small of the low back and the seat will help with postural awareness. SIT UP STRAIGHT!
2. Slow Down– Speed multiplies the impact of all stresses on the body. Going faster may get the job done at a quicker rate but it increases shock and vibration, not to mention the chance of an accident. Shock and vibration causes muscles to work harder. Therefore the operator will become fatigued much quicker than usual. Fatigued muscles lead to bad posture, which along with repetition, are two of the most common causes of musculoskeletal injury.
3. Stretch– 30 second stretches involving hands, shoulders, forearms, elbows, legs, and neck, throughout the day does a great deal to ease discomfort. Unrelieved static posture is a serious health risk. For forklift drivers, who have been confined to the controls with little or no movement, it is important to take micro-breaks and stretch appropriately.
4. Avoid Repetitive Motions In The Same Direction– If possible, when driving in reverse, avoid looking over the same shoulder. Alternating to look over the right and left shoulders can help limit repetitive motions. This concept can also be applied to using the same arm to steer the hi-lo
5. Stretch– Brief 10-15 second stretches involving hands, shoulders and neck, throughout the day does a great deal to ease discomfort. Unrelieved static posture is a serious health risk. For forklift drivers, who have been confined to the controls with little or no movement, it is important to take micro-breaks and stretch appropriately.
6. Other Recommendations
-Remove wallet from back pocket – this will reduce back discomfort.
-Upon sitting down, lean forward and shift hips to the back of the seat, positioning the spine with the correct three curve alignment.
-Slide seat forward so that feet are resting comfortably and the steering wheel and pedals are within easy reach.
-Adjust the backrest so it is tilted slightly backward.
Implementing the above noted strategies is an effective way to manage and prevent musculoskeletal disorders (MSDs). The employee must be consistent and perform these activities throughout the day regardless of whether symptoms are present or not. Also taking the time to properly adjustment the seat height, position, and seat suspension to dampen vibrations that occur when navigating uneven surfaces. Remember, healthy employee’s are more productive and less likely to experience MSD symptoms resulting in a decreased healthcare cost to the company.