How Exoskeletons Support the Back and Reduce Strain

Back pain is one of the most common work-related health issues worldwide. Whether in logistics, construction, healthcare, or manufacturing, tasks that involve frequent bending, lifting, or leaning forward put enormous strain on the back muscles and spine. Over time, this strain can lead to fatigue, musculoskeletal disorders, and long-term injuries.

Exoskeletons are wearable systems that support the human body. They are designed to tackle exactly this challenge. But how do they actually work? And why can they make such a difference for the back in particular? Let’s take a closer look at the biomechanics behind it.

The Biomechanics of Back Strain

When you lean forward, your back muscles must work hard to keep your upper body from collapsing under the force of gravity. Roughly 60% of body weight is located in the head, arms, and torso. For an 80 kg person, this means that simply bending forward puts the equivalent of around 50 kg of load on the back and hip muscles.

It’s not just the weight itself that matters, but how far it is positioned from the spine. This is known as the lever arm effect.

• When you stand upright, the center of mass of your torso is aligned with your spine, and the load is relatively small.

• When you lean forward, the distance between the load and your spine increases. This creates a torque (rotational force) that multiplies the strain on your back.

That’s why holding a 10 kg box close to your body feels manageable, but holding it with outstretched arms quickly becomes exhausting.

The effect of the lever arm. Left: person carries a bag on the side of the body. The bag is more or less aligned horizontally with the shoulder joint. As a result, the bag's weight only induces a small torque in the shoulder joint that needs to be counteracted by the shoulder muscle. Right: the person holds a bag in front of the body. This results in a considerable horizontal distance (lever arm) between the bag's center of mass and the shoulder joint's rotational axis, resulting in a higher torque that the shoulder muscles need to compensate.

Why Muscles Fatigue but Springs Don’t

Our muscles generate force by contracting, and they require constant energy to do so. Even when you hold a position without moving, your muscles are continuously burning energy. That is why maintaining a bent posture quickly leads to fatigue and discomfort.

Exoskeletons, in contrast, use mechanical springs or elastic elements that can provide a continuous counterforce without consuming energy. This makes them extremely energy-efficient: while human muscles tire with time, a spring can support posture for hours without losing strength.

How Exoskeletons Support the Back

Modern occupational exoskeletons use several principles to reduce back strain:

1. Artificial Muscle Support

   Textile-based exoskeletons, like the Auxivo LiftSuit, use elastic bands that stretch when you bend forward. These “artificial muscles” work alongside your back muscles, sharing the effort needed to maintain posture.

   
   

2. Gravity Compensation

   Exoskeletons such as the OmniSuit use elastic springs that counteract gravity when the upper body leans forward. Instead of your muscles fighting the downward pull alone, the exoskeleton offsets part of this load.

   
   

3. Energy Recuperation

   When you bend forward, potential energy is stored in the exoskeleton’s springs and released when you stand back up. This reduces the energy your body must expend for each movement, making lifting and repetitive tasks easier.

Together, these principles don’t eliminate effort entirely, but significantly reduce continuous strain on the back. Workers stay stronger, more coordinated, and less fatigues throughout the day.

Beyond Relief: Long-Term Benefits

By reducing the physical workload on the back, exoskeletons provide both immediate and long-term benefits:

• Lower fatigue during repetitive or physically demanding tasks

• Fewer musculoskeletal disorders caused by chronic overload

• Sustained productivity without pushing the body beyond safe limits

• Improved workplace safety and well-being

For companies, this translates into reduced sick leave, fewer injury-related costs, and a healthier, more motivated workforce.

Conclusion

Much of the strain on the human back doesn’t come from heavy loads alone. It’s also caused by our own body weight and posture. Exoskeletons use well-established biomechanical principles, from artificial muscle support to gravity compensation, to share that burden.

By doing so, they don’t just provide short-term relief. They enable healthier, safer, and more sustainable work in the long run.