Shin splints is a generic term that could apply to a number of different conditions affecting the front inner or outer lower limb, but not the calf or Achilles. The most common injury in this area in athletes / active people is stress fractures. There are two point affected by stress fracture – the back inner edge of the tibia (shin bone) or the front edge of the shin bone. A stress fracture is an area of bone that has been overloaded to the point that the bone cell It can be difficult to diagnose initially and will sometimes require a CT scan or MRI to confirm the diagnosis – but you should suspect a stress fracture if you have quite distinct localised pain on these areas of the shin bone and a recent history of excessive / increasing millage in your training plan.
We can usually get an indication of stress fracture from your story, training history and localisation of the pain. We can also use vibration of the tender area as a non-diagnostic sign to support the theory of stress fracture. We can use an ultrasound machine or a tuning fork over the area (both of these devices deliver vibration on to the bone) that may aggravate the symptoms.
The first line of treatment is to immediately rest from running for a period of anywhere from 2-6 weeks to let the symptoms settle down. There may even need to be a period of immobilisation in an Aircast boot.
Low intensity pulsed ultrasound (LIPUS) is an effective treatment for stress fractures and poorly healing fractures. A daily dose of 20 minutes is required. Your physiotherapist should be able to apply this treatment for you or you can buy a home use LIPUS machine called Exogen (https://www.exogen.com/patient/). The pulsed ultrasound creates vibration that stimulates the bones cells to produce new collagen and heal the damaged area, however this process does take time.
After you have rested completely for a period of 2-4 weeks you can re-introduce non-impact exercise such as swimming and cycling and start some strengthening exercises for the calf and lower limbs. Your physio will also be able to guide you back into running with a graded return to running plan.
The next most common pathology that may cause “shin splints” is medial tibial stress syndrome (MTSS). This is caused by irritation of the soleus muscle and posterior tibialis muscle on the inner part of the shin. One predisposing risk factor for MTSS is poorly controlled pronation at the foot. This causes excessive rotation and the shin overloading these muscles creating either traction and irritation where the soleus comes off the tibia or overload and aggravation of the posterior tibialis tendon.
The management of this condition is different than for stress fractures. You may be able to keep running with this problem whilst having treatment. The first course of action would be to get your running gait and biomechanics assessed to check whether your foot and ankle can control pronation. A good physio will also check your pelvic mechanics and glute muscle strength. Soft tissue release and acupuncture to the soleus and posterior tibialis is also indicated as well as using supportive k-tape. Home exercises will focus on strengthen weak glutes, but also stretching tight calves and doing exercises to strengthen the muscles which support the arch of the foot.
The final condition that could be causing “shin splints” is anterior compartment pressure. The muscles of the lower leg are surrounded by fascia, that is in part non expandable. As you exercises and blood flow increases into the anterior compartment of the leg to the side of the shin, the pressure increases. In certain people this can restrict blood flow and nerve function in the lower leg and lead to pain. This pain is typically only present when you train and gets progressively worse.
The first line of treatment is to try and loosen the fascia with good deep tissue massage, dry needling and lots of home self-massage with a foam roller or tennis ball. Igf this fails to help you may well need to see a surgeon for a fasciotomy – a surgery where they make tiny cuts in the fascia to allow expansion of the muscles when you exercise.