Shin splints, a common limiting injury that affects the shin bones in the lower leg, is a frustrating occurrence for athletes and recreational sports players alike. Whether you’re hitting the gym here in Hong Kong, training for your first 5k walk or run, or enjoy spending your weekends hiking or in the outdoors, shin splints affects almost 35% of the athletic population at some point in their lives, with up to 70% of runners being affected each year.
Shin Splints ExplainedWhile shin splints are best known as the pain that comes on at the front of the shins during physical activity, when you look deeper into what shin splints really are and what causes them, you may be interested to find that this is actually a non-specific term that can refer to three separate conditions:
- Medial tibial stress syndrome
- Exertional compartment syndrome
- Stress fracture of the shin bone
Medial Tibial Stress Syndrome (MTSS)
The most common shin pain of the three above is known as medial tibial stress syndrome. It occurs when there is too much stress or strain on the front and inside of the shin bones. This stress is typically caused by overusing the muscles that attach to the shin bone, or excess stress on the lining of the bone itself (the periosteum), leading to irritation, degeneration and the onset of symptoms. The result is pain and swelling that may stay mild, or become severe enough to stop you in your tracks during or after physical activity. Common causes for overusing the muscles at the front of the shins include overtraining or training errors, biomechanical problems in the feet or legs (like overpronation - excessively flat feet), muscle tightness (like in the calves) and a history or previous lower limb injuries. When this is paired with running or jumping activities, the strain on the shins is greatly exacerbated, tipping a person beyond their standard repair threshold. Interestingly, some researchers are now attributing heavily-cushioned footwear to be one of the causes of shin splints due to their high-tech engineering that allows athletes to land on their heels and place excess force through the lower legs.
Exertional Compartment Syndrome
The second cause of shin splints may be compartment syndrome. There are four compartments in your lower leg, distinctly separated by your tissues. Each compartment only has so much space to house its muscles, arteries, nerves and other tissues. Damage or overuse to muscles within the front (anterior) compartment means that these muscles swell, increasing pressure within that compartment and resulting in pain or discomfort, a feeling of tightness, and a swollen appearance. As the muscles within the anterior compartment are heavily used during running sports, these symptoms often start during or after exercise. When the muscles have a chance to rest, the swelling subsides, and any painful symptoms should notably ease. Unfortunately, due to the nature of the cause, the same symptoms can also quickly recur the next time you’re physically active. It’s important to make a clear distinction that this type of compartment syndrome is also known as chronic (or exertional) compartment syndrome, and while you will benefit from assessment and treatment with your physiotherapist to prevent the anterior muscle compartment from overloading, developing this time of compartment syndrome is not limb-threatening. On the other hand, acute compartment syndrome is considered a medical emergency and you must contact your doctor immediately for urgent medical care which almost always involves surgery to prevent permanent damage. Signs for acute compartment syndrome include severe pain, pale skin tone at the leg, numbness, a faint pulse and weakness when trying to move the affected leg.
Stress fractures are caused by repetitive stress and pressure on a bone, in this case the shin bone, which can occur when undertaking running and jumping activities, paired with other factors that increase the stress on the shin bone, like your foot and leg biomechanics, muscle imbalances and training errors. Starting as small microcracks with little symptoms or pain, stress fractures can quickly progress to severe, painful fractures that can see you sitting on the sidelines while you recover. Symptoms of a stress fracture at your shin bone (tibia) may include pain and tenderness along the bone in a specific area. You may or may not see some swelling, and the pain can worsen with physical activity and ease with rest. As stress fractures progressively worsen, starting with very mild symptoms and having the potential to progress to severe pain and discomfort, it's important to treat stress fractures as early as possible.
What Causes Shin Splints?
The nature of shin splints is often multifaceted, meaning that there are several larger and smaller factors that all lead to the increased loading on the shin bone that eventually results in shin splints. Common contributing factors include:
- Training errors - particularly suddenly increasing your training (intensity, duration or the type of training you’re doing such as switching to hill running) without adequate preparation. Your level of activity should always be increased in a gradual and controlled manner to allow your body to adapt.
- Muscle imbalances - weak or tight calf muscles, as well as other muscles in the feet and legs, can contribute to shin splints. Imbalances in these muscles can affect the way you walk or run, putting more stress on certain areas of your leg.
- Poor running technique - with running placing a lot of force through your shins with every step, having a poor running technique or other running-related issues is a common contributor to shin splints.
- Poor footwear choices - your feet rely on your shoes to provide adequate support throughout both the feet, arches and ankles. Without this, the stress on the muscles, joints and bones in your feet and lower legs can increase significantly.
- Foot and leg biomechanics - having biomechanical issues like flat feet can make you more prone to developing shin splints as they force your lower leg muscles to work harder to stabilise your feet and legs during movement.
Physiotherapy For Shin SplintsOur physiotherapists here at PhysioCentral in Hong Kong work extensively alongside those with shin splints to aid their recovery, while also helping reduce the likelihood of shin splints returning and interfering with their exercise or daily activities in future. The first step in your recovery focuses on reducing the strain on the shin bone and its structures. While in part, this involves modifying your current training or activity schedule to focus on lower-impact movement that won’t overload your shins and promote the condition to worsen, it also includes addressing the (often) several causes of your shin splints. Our physios will get a good understanding of all your causative or contributing factors during your assessment with us, and then address them all appropriately. Without this crucial step, even if you were to get temporary relief from your shin splints pain, the likelihood of your symptoms continuing to recur is high. Addressing the causative factors may look like:
- Working with you on gait retraining to address improper technique
- Working through any training errors, including planning safe training increase increments
- Creating a strength rehab program, which will look at any muscle weaknesses that are contributing to your shin pain such as reduced calf strength or endurance, or poor hip strength
- Creating a stretching program to address areas of tightness that are having a chain effect on other areas of the body, leading to increased loading on the shins
- Making footwear recommendations to those that will give you adequate support based on your foot biomechanics and the type of activities you’re doing
- Performing lower limb massage
- Teaching you strapping and taping to help under certain circumstances (like during events) to reduce your likelihood of recurrent pain