If you are a runner there is no doubt you have heard of shin splints, this frustrating injury causes pain along the shin bone (tibia). Perhaps, this injury delayed your marathon training or stopped you from attending the Park Run on Saturday morning. This wouldn’t be uncommon, as it is thought that around 35% of runners will experience this injury at some point in their training (1).

But what exactly are shin splints?

The term shin splints is often thrown around in running groups and you will see Instagram posts claiming to have the best exercises to fix this bothersome pain. However, the term itself is not correct and it doesn’t provide a diagnosis but rather an umbrella term for many different problems that cause pain at the shin. Some studies suggest there are over 30 possible causes of lower leg pain in athletes (2). Unfortunately, this causes confusion and many runners will not receive the right advice and management for their problem (3).

Let's break this down and get the misinformation cleared up…

Medial Tibial Stress Syndrome

Medial tibial stress syndrome is one of the most common causes of shin pain in runners and is considered by many athletes and health professionals to be the correct medical language for shin splints. To make it even more confusing the actual cause of medial tibial stress syndrome is widely debated.  Some studies suggest that the periosteum (a sheath that covers the bone) becomes inflamed due to repetitive contractions of the deep muscles at the calf that allow you to plantar flex your foot. However, more recent research suggests that medial tibial stress syndrome is a bone stress reaction due to the bone being irritated repetitively. This might occur if you increase your distance or speed too quickly. A study in 2018 took biopsies of athletes with medial tibial stress syndrome and found there was unrepaired microdamage accumulation (4). This suggests the bone was not recovering after exercise but remaining in an inflamed state, leading to reduced bone strength and injury. 

What are the symptoms of medial tibial stress syndrome? (5)(6)

• The pain will cover over 5cm of the medial border of the tibia, usually from the middle of the tibia bone towards the ankle.

• The pain will occur when exercising (running, football, walking etc)

• If you perform a single leg hop it should be pain-free

• The symptoms can last from hours to days after the exercise

• It can be tender to touch the area

What are the risks of developing medial tibial stress syndrome? (4)

Too much too soon

This could be increasing speed, distance, volume, intensity or terrain quicker than your tissues can handle that increase. Usually, medial tibial stress syndrome will occur in new runners and those returning to training after a long break.

Tightness

Tightness in the calf muscles and tibialis posterior. These muscles attach to the tibia and if tight this will put excess stress on the bone when running.

Weakness

If the muscles of the lower legs and in particular the calves are weak you will have difficulty absorbing the forces produced by running.

Reduced range of movement

If your ankle range is stiff into dorsiflexion (foot pointing upwards) your body may have to compensate and the ankle will pronate (roll inwards) putting more stress on the tibia and fibula.

Biomechanics and running form

Some studies show that those who have a high foot arch, pronate or have a cross-over gait when running are more at risk of developing medial tibial stress syndrome. 

How can you fix it?

The good news is, that in most cases with the correct advice and a period of rest, the symptoms of medial tibial stress syndrome will usually clear up and you can return to pain-free running.

Do not run through pain

Whatever you do, please do not try to run through the pain of medial tibial stress syndrome as this could lead to the development of a stress fracture.

Reduce the training load

Follow a return to running programme to safely and slowly build up the volume. For new runners, I would recommend the Couch to 5k as it is easy to follow and includes walk breaks.

Rest

Collagen synthesis, a process essential for repair and growth will take between 24-48hs after an impact exercise like running. I would suggest following your running day with a rest day or a low-impact exercise as this will help aid your recovery.

Running shoes

Invest in a good pair of running shoes that offer support and cushioning. Ideally, you should replace your running shoes every 300-500 miles.

Strength exercises

Building muscle strength in the calves, hamstrings, glutes, quads, foot and core. This will help reduce forces that are put through the tibia and will also improve your endurance and efficiency.

Mobility and stretching

Work on ankle range of movement and calf and hamstring stretching

What do I do if the pain isn’t improving?

If symptoms are not improving, the pain does not ease with rest from running or your symptoms do not fit the pattern of medial tibial stress syndrome you need to seek assessment from a physiotherapist. If the pain is not settling you may have sustained a stress fracture of the tibia. Another common cause of shin pain in young adult runners is chronic exertional compartment syndrome which is caused due to vascular or nerve compromise.

How do I know if I have a stress fracture?

• You will experience point tenderness at the tibia

• You will struggle to exercise through the pain

• You may have pain at rest and it may wake you up in the night

• It will be painful to perform a single leg hop

• Be cautious of a stress fracture if you have relative energy deficiency (low energy availability caused by lack of fuel and high activity levels) this can lead to reduced bone density and an increased risk of stress fractures

• If you think you have a stress fracture, seek assessment from a physiotherapist or GP

How do I know if it is chronic exertional compartment syndrome?

• Symptoms often occur on both legs

• Tightness sensation, burning or squeezing-like pain

• Pain when exercising which gets worse as you continue

• Pain improves quickly when you stop exercising

• More common in young adults

• If you have these symptoms seek assessment from a physiotherapist or GP

Conclusion

Shin splints is an unhelpful term to describe many injuries that cause pain in the shin. Medial tibial stress syndrome is a common cause of shin pain in runners with symptoms usually occurring in recreational runners or those returning to running after a period of rest. Medial tibial stress syndrome is an overuse injury and symptoms should ease with a period of rest, individualised advice and a return to running programme. Other common causes of shin pain include a tibial stress fracture and chronic exertional compartment syndrome. If symptoms do not ease with rest and advice an assessment from a specialist physiotherapist is recommended.