Having weak and brittle bones due to a loss of bone mass can be a significant risk factor for injury during exercise. In general, weak bones are:
- More susceptible to fractures from forces generated on them during physical activity.
- More likely to break as a result of accidents during exercise, such as slipping and falling or injury from a piece of equipment. Even minor accidents, such as twisting your leg can result in a broken bone.
What Issues Are Posed With SCI?
Bone loss can impact anyone, however, individuals with SCI are affected at much higher rates than the general population. In fact, it is estimated that 80% of individuals with chronic SCI have bone loss significant enough to be diagnosed with osteopenia or osteoporosis and decreases in bone density of 30% to 40% in the legs is typical after SCI.
Most of the bone loss occurs below the level of injury; therefore, individuals with quadriplegia experience the greatest overall bone loss. Individuals with paraplegia also experience significant bone loss in the lower extremities but maintain bone density in the upper body.
The primary reason for bone loss after SCI is due to the lack of mechanical stress on the bones below the level of injury. This is because every time we move, and even when we are standing still, our muscles are working to support us. When a muscle contracts, it places a mechanical stress on the bone it is attached to and the body responds to the stress by creating more bone. When the muscle can’t contract, the bone-building process ceases and bone mass is gradually decreased over time.
Other factors that contribute to the loss of bone mass in individuals with SCI include:
- Hormonal changes
- Changes in metabolism and blood pH
- Poor blood flow to the limbs
- Altered gas and nutrient exchange at the bone.
How to Reduce Risk When Exercising
You can significantly reduce your risk of fractures during exercise by always taking the following steps:
- Exercise in a safe environment. Since accidents are a common cause of fractures, the best way to avoid them is through prevention. This means exercising in a safe environment.
- Make sure that your training environment is safe and free from obstacles that may cause a fall.
- Learn safe transfer techniques to minimize the possibility of injury while transferring from your wheelchair to equipment and back again.
- Use straps or other adaptive devices to make sure that your trunk is properly supported on equipment and ensure that you can maintain your balance throughout the exercise.
- Take the time to properly position and secure your wheelchair prior to each exercise.
- Use appropriate equipment. For example, if you have limited hand function, using cuff weights or weights with straps will allow you to safely perform exercises without the risk of dropping the weight on yourself.
- Avoid movements with a high fracture risk. Some movements put excessive stress on the bones, which can lead to fractures.
To avoid fractures, always:
- Perform all movements in a slow, controlled manner and always within your range of motion.
- Avoid movements that put excessive stress on the bones. Movements to avoid include:
- Twisting (especially twisting with a weight or other load)
- Extensive flexion or extension
- Overstretching can put significant stress on the bones, causing fractures. When performing assisted stretches (i.e. stretches with a partner), make sure your partner avoids extreme tension.
Finally, remember to always check your body after each workout for any signs of fracture, including swelling, redness, and bruising.