Most runners will experience an injury at some point in their running career. If you don't, you're either very lucky or very wise with your training and blessed with fantastic form.

There are certain injuries that seem to go hand in hand with running. Talk to any experienced runner, and they can tell you all about the dreaded shin splints, IT band syndrome, plantar fasciitis and Achilles tendonitis.

But what about the less common injuries? There are plenty of others that have a strong correlation with running — for example, patellofemoral pain syndrome, peroneal tendonitis and pes anserine bursitis. While these conditions are less common, there is still plenty of information available online for runners, and all physical therapists will be aware of and able to treat such issues.

The problems come when a sneaky little injury masquerades as something more well known. It is understandable that this may baffle the runners themselves when their home treatment seems to have no effect, but sometimes these pesky conditions can even have an experienced therapist fooled.

Here are the top ones to look out for:

1. Shin stress fractures vs. shin splints

Stress fractures to one of the two shin bones usually occur due to a sudden increase in training volume. They can occur in either the tibia or the fibula, but tibia stress fractures tend to be more common due to the increased load-bearing role of this bone.

These tend to also be mistaken for shin splints more easily due to the location of pain at the front of the lower leg, which only initially occurs when running. The differences to look out for include:

  • Stress fracture pain being easier to pinpoint to one specific spot — shin splints are usually more vague.
  • Stress fracture pain is on or deep inside the shin bone; shin splints is usually more medial (to the inside).
  • Shin splints are often worst when you start to run and then ease off, only to return later on. Stress fractures may feel fine to start with and pain gradually increases with distance.
  • Vibration from a tuning fork or even (careful) application of ultrasound therapy will cause pain when a fracture is present.

2. Piriformis syndrome vs. lumbar disc injury

The piriformis is a relatively small muscle found deep inside the buttock. It lies close to the path of the sciatic nerve, and in some cases the nerve has even been shown to pass directly through the muscle.

Due to the typical "sciatica" symptoms of referred pain down the posterior/lateral leg with potential for tingling or anesthesia, piriformis syndrome is often mistaken for other causes of sciatica most commonly a lumbar disc herniation.

Here's how to tell if your pain could be coming from your butt:

  • No history or current feelings of lower back pain
  • A deep, dull ache in the buttock on one side
  • It may feel as though you are "sitting on a stone"
  • Sitting for long periods is often worse than standing — this is the opposite for disc issues
  • Your range of motion into hip rotation is limited and/or painful
  • You have full and pain free back motion

3. Calcaneal stress fractures vs. plantar fasciitis

The calcaneal (heel) bone is occasionally fractured by your average runner, although this injury is more common in those training for military-style events in boots and with heavy rucksacks. This form of fracture can easily be mistaken for plantar fasciitis, a common running injury that also presents with pain under the heel of the foot.

Calcaneal stress fractures will:

  • Be worse with increased activity, whereas PF is usually worst after periods of rest and improves as you walk around
  • Cause pain on the sides of the heel, whereas PF causes pain underneath and into the sole of the foot
  • Cause pain when the heel is firmly squeezed from both sides

4. Tensor fascia latae myofascial pain vs. trochanteric bursitis

The tensor fascia latae (TFL) muscle is located on the outer hip and is an important muscle in stabilizing the pelvis. It works particularly hard when running to stop the weight-bearing hip from adducting, and therefore the pelvis dropping.

Due to this, it is common for a lot of tension and often "trigger points" to develop within the TFL in runners. These trigger points can radiate pain, most commonly down the lateral leg, as well as within the muscle.

Problems with this muscle are not well recognized, so such a pain referral pattern can be mistaken for either sciatica (and therefore piriformis or lumbar disc issues) or trochanteric bursitis.

Your hip or outer leg pain may be due to TFL if:

  • You have full movement and no pain in your lower back
  • You can lay on the affected side without pain
  • You have a slight restriction or increase in pain on adducting the affected hip (moving the leg across the body)
  • It is tender to press into the TFL muscle — this may even refer pain down the leg
  • There is no soreness when pressing over the greater trochanter

So there you have it, four infrequent running injuries that may profess to be something a lot more common. These are always worth a thought when faced with a seemingly conventional running injury that just doesn't seem to respond to all the right treatment.