How to prevent shin splints when training for distance running
If you are a runner or involved in running sports you may have heard about, or experienced shin splints before. Read on to find out exactly what this means, and to learn more about how to preventing and treating shin splints when training for distance running.
What are shin splints?
If you are a runner or involved in team sports you may have heard about, or experienced “shin splints" , otherwise known as medial tibial stress syndrome (MTSS) before. Many forms of shin pain will often be described as “shin splints”, however this is an umbrella term that encompasses as many as 20-30 different diagnoses so it is best to get this checked out by a professional! In short, shin splints, are a form of bony stress reaction (explained below) but in order to confuse us all, it is often referred to as shin splints or MTSS. In many cases, it can be managed without too much hassle, but can progress to more serious and debilitating conditions such as stress fractures if left untreated.
The surface of the shin bone (tibia) is covered in a layer known as the periosteum. This layer is well supplied by blood vessels and nerves which is great news for it’s healing capabilities but also results in it being a very capable source of pain.
Bone responds to stress or load by strengthening, and stress is required to create strong, healthy bones. However, if the stress on the bone is too great, then a stress reaction occurs. If adequate recovery is not allowed to provide bone with the opportunity to strengthen, then a stress fracture can occur.
The process can be broken down into three simple stages, bony oedema, inflammation of the periosteum (the bone’s sheath) and then stress fracture. The early stages of this process are often pain free, and typically resolve without intervention. When inflammation of the periosteum occurs, diffuse pain is often reported- the type of pain that many identify as shin splints! If this process is allowed to progress to the third stage (stress fracture) then the pain is often quite localised, and runners find they are often unable to push through the pain. Stress reactions or fractures most often occur on the medial tibia (inside) but can also occur anteriorly (at the front)- these are less common, but require a longer period recovery and are more complicated to manage. It is best to have any recurrent shin pain assessed by a professional, as the period of rehabilitation could be anywhere from one week to six months!
So, what are the causative factors? And how do you prevent them?
1. Poorly managed training loads
This includes a sudden increase in mileage, a different training surface or a change in intensity. Most bony stress injuries occur in the first month of commencing a programme, or making a change to your regular training as it takes time for bone to adapt to new loads. When beginning any new training programme or shaking things up, make sure to include recovery days and don’t make every session the same- continually running the same 20km route 3 days a week won’t make you a better distance runner. Include shorter, speed sessions in your training and allow yourself at least 2 recovery days per week, more if you’re new to running! As a general rule, don’t overload any session by more than 10%. That is, if your longest Sunday run to date was 10km last Sunday, don’t try to run any more than 11km this Sunday. Similarly, if you ran 5x1km efforts at 4:30km/hr last week, then don’t aim for 4minute kms this week- the increase in intensity exceeds the 10% rule!
2. Poor running technique and altered biomechanics
The body acts as a kinetic chain- put simply, movement at any joint can have an effect on those above and below it. What happens at your hips when you run can influence the action of your foot and vice versa. There is a wide range of “normal” when it comes to running mechanics, however with good technique and control forces are dissipated by muscles, tendons, ligaments and bones. Poor biomechanics, technique or control may result in some areas becoming overloaded. Overprontation (excessive roll-in of your foot in standing or when you run) or high arches may contribute. Overpronation may be functional (only happens when you run) or may be just the way you are! A physiotherapist will be able to assess this, and may refer you to a podiatrist if necessary. Poor running technique may also increase your risk of developing shin pain - overstriding (see the image below) is one technique flaw often seen in people training for distance running. This involves landing with your foot out in front of your knee, which changes the way impact forces are dissipated through your leg and places increase load through your shin.
Again, a running analysis with your physio may help to identify some of these technique flaws, however keep in mind that what happens during your assessment may not be representative of how you move 22km into a long run when you are fatigued! Hip drop (the hip moving in towards the other leg while running) has also been linked to shin splints in research. This may be due to weakness in the gluteal muscles that stabilise your pelvis, or tightness in the muscles that bring the leg in the midline, so often a thorough analysis of your movement control is required to prescribe the most effective exercises for correcting this technique flaw! Weakness in your calf muscles may also contribute- check how you compare side to side with a simple calf raise exercise as shown below. Start with feet hip width apart, and slowly shift your weight across to one side. Using fingertips for balance, slowly raise onto the ball of your foot bringing your heel up over your toes. Lower down slowly and repeat for as many as you can, then compare the other side. 20-25 is the goal!
3. Muscle tightness and ankle range
Tightness in your tibialis anterior or calf muscles may increase the stress on your tibia during running, so ensuring adequate flexibility is important. A lack of dorsiflexion (your ankle bending so that your toes come back towards you) during running may result in overpronation as a compensation, which changes the way you absorb impact. Adding in stretches for your calf and leg muscles will help to prevent shin splints. The image below is an example of a calf stretch. Try doing these daily for 3x1minute holds each side. If you are already suffering, speak to your physio about these stretches before beginning as stretching during a flare-up may exacerbate pain!
4. Running Shoes
Old, warn out shoes will lose their ability to support your foot. There is no hard and fast rule, but you should change your runners every 800-1000km. Ensure the shoe you have is the best fit for you- a good way to do this is by having a running analysis done in store. Be wary of stores that sell you a runner based on your standing posture- as already discussed what happens at your foot when you run may be very different to when you are standing still! Active Feet or SoleMotive will be able to perform a running analysis for you in-store and make a recommendation based upon this.
Preventing and treating shin splints is multi-faceted and best to be done guided by your physiotherapist. Being aware of the risk factors early will help you avoid this debilitating condition, as prevention is always better than a cure!