Uncomfortable postures – Moderate risk (> 2 hours total per day)
Uncomfortable postures with moderate risk (more than 2 hours total per day) can contribute to musculoskeletal discomfort and increase the likelihood of injury. Prolonged periods in uncomfortable positions can lead to tension, fatigue and long-term health problems. To mitigate the risks associated with awkward postures, consider the following ergonomic principles:
- Frequent break: Encourage workers to take short breaks to stretch and change their body position regularly. This helps reduce the time spent in uncomfortable postures.
- Ergonomic furniture and equipment: Provide adjustable chairs, desks and other equipment to accommodate different sizes and shapes. This allows employees to customize their workstations for comfort and proper alignment.
- Training and Awareness: Educate employees on proper ergonomic practices, including the importance of maintaining neutral body postures. Raising awareness can lead to better habits and a reduced risk of musculoskeletal problems.
- Workspace layout: Organize workspaces to minimize the need for awkward postures. Position tools, equipment and materials within easy reach, reducing the need to stretch or bend excessively.
- Use of ergonomic tools: Introduce tools and equipment designed to reduce strain and awkward postures. This may include keyboards, mice, or ergonomic tools that promote neutral positions for the wrists and hands.
- Job rotation: Implement a job rotation schedule to vary activities and reduce prolonged exposure to specific uncomfortable postures. This can help distribute physical stress across different muscle groups.
- Stretching and exercise programs: Encourage employees to participate in stretching and strengthening exercises to improve flexibility and muscular endurance. This can offset the effects of prolonged uncomfortable postures.
- Individualized Assessments: Conduct ergonomic assessments to identify specific risk factors related to employee workstations. This can help tailor interventions to individual needs
Uncomfortable posture takes into account the following points:
- Neck tilted more than 30° in any direction: Excessive neck tilt can lead to muscle strain and neck problems over time.
- Elbow above shoulder: This position can cause arm and shoulder muscles to fatigue quickly, increasing the risk of strain and pain.
- Hands above the head: Constantly holding your hands above your head can put pressure on the shoulders, neck and arms, leading to muscle fatigue and discomfort.
- Back leaning forward more than 30° (without support or possibility of varying posture): Excessive flexion of the back can lead to lumbar and back tension, increasing the risk of spinal problems.
- Squatting: This position can put increased pressure behind the kneecap, potentially causing knee injuries over time.
- Alternatives to bending your back to stoop: Looking for alternatives to bending your back to stoop avoids excess strain on the spine.
- Increases pressure behind the knee cap and can cause knee injuries over time: Certain positions can put constant pressure on the knee cap, increasing the risk of injury over time.
- Kneeling: The kneeling position can create pressure both in front and behind the kneecap, which can cause discomfort and joint problems.
By taking these elements into account, it is possible to better understand what an uncomfortable posture is and adopt preventive measures to reduce the risk of muscle tension, pain and injuries associated with these uncomfortable positions.
Definition of High Hand Strength: Pinch Grip > 2 kg or 4 lb per hand, Power Grip > 5 kg or 10 lb per hand, both for more than 2 hours
High hand strength refers to the ability of the hand to exert significant force when grasping objects. Here is the definition of high hand strength:
- The pinch grip involves grasping an object between the thumb and index finger. Pinch grip strength greater than 2 kg or 4 lb per hand means being able to grip an object between the thumb and index finger with force greater than 2 kg (4 lb) for each hand individually.
- The power grip involves grasping an object with the whole hand, not just the thumb and index finger. Power grip strength greater than 5 kg or 10 lb per hand means being able to grip an object with the whole hand by exerting force greater than 5 kg (10 lb) for each hand individually.
To be considered high hand strength, both the pinch grip strength and the power grip strength mentioned in the definition must be maintained for more than 2 hours. This demonstrates an ability to maintain high grip strength over an extended period of time.
It is important to note that high hand strength can be influenced by various factors such as training, general fitness, age and overall health. Practicing hand and grip strengthening exercises can help improve hand strength and achieve the levels mentioned in the definition.
Highly Repetitive Movements
Highly repetitive movements refer to repeatedly performing identical types of movements using the same muscles, tendons, or joints. Here’s when repetition becomes a risk:
- Neck : More than 2½ hours
- Shoulder : More than 2½ hours
- Upper arm/Elbow : More than 10 hours
- Forearm/Wrist : More than 10 hours
- Finger : More than 200 hours
A moderate risk is present…
A moderate risk is present if these frequencies are exceeded for more than 60 minutes continuously, or more than 2 hours total per day. High risk is present in the following cases:
- Risk linked to repetitive movements : More than 6 hours in total per day.
- Risk linked to repetitive movements + Intense manual exercise : More than 2 hours per day.
It is important to note that these risk thresholds can vary depending on different factors such as the individual, general physical condition and overall health. It is recommended to take regular breaks, practice stretching and strengthening exercises, and consult a healthcare professional if any pain or discomfort persists.
Preventing injuries from highly repetitive movements involves good ergonomics, regular breaks, appropriate muscle strengthening exercises and proper management of working time.
When does impact become a problem?
Impact can be a problem in the following situations:
- Moderate risk : Using the hand or knee like a hammer more than 10 times per hour, for more than 2 hours per day.
- High risk : Using the hand or knee as a hammer more than once per minute, for more than 2 hours per day.
Heavy, Frequent or Clumsy Lifting
Lifting heavy, frequent or awkward objects can cause health risks. Here are some indications to take into account:
- Weight of 75 pounds (approximately 34 kg) : Lift an object weighing more than 75 pounds once a day.
- Weight of 55 pounds (about 25 kg) : Lift an object weighing more than 55 pounds more than ten times a day.
- 10-pound weight (approximately 4.5 kg) : Lift an object weighing more than 10 pounds more than twice per minute, for more than 2 hours per day.
- 25-pound weight (approximately 11 kg) : Lift an object weighing more than 25 pounds above the shoulders, below the knees, or at arm’s length more than 25 times per day.
Vibration of the arm and hand
Prolonged exposure to vibrations from tools can lead to health problems related to the arms and hands. Here are some indications to take into account:
- High vibration tools : Using high vibration tools, such as jackhammers, chainsaws or impact tools, for more than 30 minutes per day can pose a high risk.
- Moderate vibration tools : Using moderate vibration tools, such as grinders or sanders, for more than 2 hours per day may pose a moderate risk.
