Having had 3 questions in 2 days and 4 in the last week about lower leg problems I thought perhaps I should try to explain a bit about the muscles of the lower leg, how they work and what problems can occur.
I will try to break this down in to 3 areas:
Anterior / Front / Shin
Posterior / Back / Calf
Lateral / side (outside)
And within these sections the muscles involved, what they do and the common problems that occur.
1. Anterior / Front / Shin
Most of the pain that occurs in this area is commonly referred to as ‘shin splints’. The muscles involved here are Tibialis anterior, Extensor Hallucis Longus (big toe extensor), and Extensor Digitorum Longus (toe extensor). This group of muscles bring the ankle, foot and toes up towards the knee. Injuries that occur in this area are usually one of three.
Firstly – Stress fractures, not muscular and not that common but worth talking about. Usually caused by high impact, poor running technique and particularly poor technique running downhill may lead to this. Pain is usually a sharp pain on impact, and a very specific small painful spot on applying pressure to the shin bone (tibia).
Secondly – Generally known as Medial Tibial Stress Syndrome (MTSS) the runner gets pain build up whilst running and a long tender area down the front of the shin where the muscle attaches to the bone via a membrane. The attachment becomes inflamed as a result of repetitive impact. It may be that this is exacerbated by excessive tightness in the calf muscles but it is generally caused by poor technique in the form of heel striking on an extended over striding leg.
Thirdly – We have Anterior Compartment Syndrome, here a build-up of excessive pressure/tension occurs within the sheath around the muscles often due to tension within the muscles. This may be the result of an injury where bleeding has occurred and/or scar tissue may have built up. Or just because of an adaptive shortening of the muscles due to an over emphasis on lifting the toes and foot up.
2. Posterior / Back of leg / Calf
The muscles involved here are Gastrocnemius and Soleus muscles which are big powerful muscles which plantar flex the ankle meaning that they extend the ankle joint to enable you to push off the ball of your foot as in jumping and running. Lying underneath these muscles are a number of smaller muscles that control ankle stability and toe movement. (Tibialis Posterior, Flexor Hallucis Longus, Flexor Digitorum Longus). Injuries include:
Calf Strain/Rupture – Usually occurs in take off as in jumping and are most common in racket sports. They can however occur through running more often in slippery conditions. At best a minor tear will feel like an elastic band has snapped, at worst you will hear a pop and feel like you have been hit or shot in the back of the leg. At best you will limp and struggle to carry on and at worst you will collapse on the floor and be unable to stand on the leg. You will usually have bruising which can range from a small circular bruise to bruising spreading across and down your leg from the site of the injury to the ankle and foot. Ice is always the first course of action here with elevation of the limb to minimise the bleeding into the area which could lead to a large build-up of scar tissue.
Ruptures are classified by Grades from 1 to 3 and the system of classification is pretty simple. If the tear is a partial rupture of less than 1/3 of the muscle volume at that point in the muscle it is classed as Grade 1. A partial rupture of between 1/3 and 2/3 of the muscle is classed as Grade 2, and anything above 2/3 of the muscle size (circumference) is classed as Grade 3 a truly total rupture is when the two ends of the muscle or tendon are completely separated. A grade 3 tear usually require surgery to be repaired. The most common site of a tear is in the muscle just above where the tendon joins the muscle. However tendon ruptures also occur and total ruptures of the Achilles tendon are fairly rare but very nasty.
Achilles Tendonitis – Inflammation of the Achilles tendon. It is usually sore to walk or run on, it feels warm/hot and tender to touch and is usually relatively red in colour compare to the other one. Usually caused by ‘overuse’/repetitive strain or by friction such as from the heel of a shoe rubbing. Most commonly occurs in runners that run on the forefoot or toes.
Posterior Compartment Syndrome – As per anterior compartment syndrome although there are actually two compartments a superficial and deep compartment. Causes can be muscle damage such as bruising or tears especially where you feel the injury and it feels tender or bruised to touch but you cannot see the bruising as the bleeding builds up within the compartment which increases pressure within the compartment. After a few days of icing the area massage should be used to try and help remove the pressure from the muscle. Sometimes in cases where the problem persists for a long time a fairly simple surgical procedure may be required to split the sheath around the muscles to allow the muscle fibres to work properly.
Adaptive Shortening of the calf muscles. I briefly mentioned this within the anterior section but it is much more common in the Calf muscles and can lead to compartment syndrome and Achilles problems. It is most common in women who wear high heels a lot, but basically anyone who for whatever reason has the foot in a plantar flexed (pointed) position for long periods can suffer from this. There becomes a lack of flexibility in the calf muscle and then if you try to run or do other activities that place a stretch on the calf muscle the result is usually pain.
3. Lateral / outside leg / Peroneal Muscles
Pain down the outside of the lower leg that usually comes on with running or after ‘spraining’ your ankle is related to the peroneal muscles whose function is to control supination of the foot. I emphasised ‘spraining’ because what I actually mean is turning your ankle over on an uneven surface and this is what most people term spraining an ankle. Technically however a sprain is an injury to a ligament, an injury to a muscle or tendon is a ‘strain’ not a ‘sprain’. So if the pain is on the outside of your lower leg you will have strained a peroneal muscle. This is generally better than rupturing (spraining) the ligaments in your ankle, felt on the outside of the foot just below the knobbly bit of your ankle. Muscles will heal reasonably well normally ligaments are poor healers as they have very limited blood supply.
You can also get peroneal pain through overuse/repetitive strain through running on uneven surfaces or if you are wearing shoes with too much arch support for you, as they will be preventing your natural pronation (roll inwards) and causing unnatural supination (roll outwards).
I hope you find this useful and interesting. I have tried to keep it simple but as you can probably now understand the ankle is a complex joint with lots of muscles involved in its control and stabilisation. Remember it is always best to get an injury checked by a professional and in most of these cases sports massage together with stretching will help. In some cases corrective exercise will also be necessary to help address the muscle imbalances which may even stem from elsewhere in the body.