Loading your bones

Bone-related overuse injuries are not hugely prevalent in professional performers, however they are seen occasionally. These type of issues are usually found in the lower limb, specifically the bones of the foot, tibia and very occasionally the fibula. Within the performing sector there area couple of sub-groups that are more prone to these types of issues than others and they are the older performer and also young female performers.

 

To start these exercise and bone health posts we will start with simply how exercise can improve bone structure and what to mindful of when exercises when it comes to bone health, as it’s important for most of us to consider especially as we advance in years.

Figure 1 Shows the directions of force that pass through bones (a) compression aka axial compression, (b) distraction, (c) shear, (d) bending and (e) torsion. Article

During any movement or exercise there are multiple types of stress that gets placed into bones. These can be seen in figure 1, and include axial compression, distraction, shear, bending and torsional stresses. The most effective means of improving bone structure, in terms of bone density measures, is to utilise compressive or axial compression type loading on bones. This involved the stress being aligned straight up (or down) the bones length… Alas, compressing the bone. In most cases the exercises about moving a weight upwards(vertically) against gravity, with the bones aligned in the same direction that you are pushing.

 

The types of exercises that provide this kind of stress are:

- Leg press

- Squat patterns

- Bench press

- Overhead presses

- Cleans

- Deadlifts

- Jumping

- Running

 

As you can see the exercises that provide this a larger compound movements and provide massive value for athletic performance.

 

The interesting part (at least the geek in me thinks so) is understanding what is going on when performing these axial compression exercises. Like muscle, bones structure is determined by how much load is being placed on it. Bones get larger when loaded regularly, and thinning when not being loaded. If bone is damaged at a microscopic level it gets replaced and made stronger, needing time to recover. Just like muscle.

 

Put simply, cells called osteocytes senses mechanical load, which places the order for osteoclasts (OCs) or osteoblasts (OBs) to be expressed and start to work. Osteoblasts are the cells that lay new bone tissue, whilst OCs are responsible for the absorption of bone. Balancing the work of the OBs and OCs is the key relationship in bone health.

 

When insufficient loading is taking place OB activity is reduced, laying less new bone whilst osteoclasts activity may remain relatively high. Essentially tipping the balance to less robust bone (more being absorbed than being made). However, with adequate loading OB activity is increased and when dosed appropriately will lead to an improved bone structure, making them stronger and more able to deal with higher forces.

 

One note of caution is that too much loading can end up being an issue itself, and when introducing or reintroducing the types of exercises we spoke about above try to remember that more is not always better, and to consider your performances too, as balancing the new loading with appropriate recovery is key to progress efficiently.

 

We’ll cover more issues like this and provide more extensive solutions via Production Education, which you can find out more about very soon.

 

Thanks for reading

 

Barry