Calf pain is a common problem especially in athletes whose chosen sport involves running. If not diagnosed and managed properly it can persist for months or recur causing disruption to training routines and frustration. The calf consists of two muscles, the gastrocnemius and the soleus. They both share a common tendon, the Achilles tendon, that inserts into the heel (calcaneus). Both muslces have slightly different roles with the gastrocnemius being more prone to injury probably due to the fact it acts on both the knee and ankle.
Common calf injuries include: muscle strains to either the gastrocnemius or soleus; muscle contusions; muscle cramps; referred pain from the lumbar spine (low back) and delayed onset muscle soreness (DOMS).
Other less common causes of calf pain are: compartment syndrome; referred pain from other areas such as structures within the knee, entrapment of arteries either within the calf or higher up in the leg; stress fractures in the lower leg and varicose veins. Deep vein thrombosis (a blood clot in the deep veins of the leg) is not common but requires immediate medical attention. An in depth discussion of the less common causes of calf pain is beyond this blog. If your injury is not responding to treatment as expected it is wise to visit your doctor as these causes of calf pain require further investigation and/or medical management.
Calf muscle strains
Calf muscle strains (a tear in the muscle of varying severity) are by far the most common cause of calf pain. Although they can occur any where within the calf the area most often involved is the top part of the calf towards the inside of the leg (medial head of gastrocnemius). This injury is often associated with sudden accelerations. Calf muscle strains are not always caused by acute injuries. You can develop muscle strains over a prolonged period when the tissues fail to cope with the load being placed on them. Micro-trauma (muscle damage that may go unnoticed) leads to macro-trauma (the onset of symptoms such as pain) and a cycle of injury, incomplete healing and further injury can begin.
After an acute injury such as a calf muscle strain you could follow the RICE treatment regimen. Some people prefer PRICE where the ‘P’ stands for professional advice. How long you continue the regimen will depend on the severity of the injury. Restoring muscle length with calf stretches and restoring muscle strength with calf strength exercises is important to prevent re-injury. In addition you must look at contributing factors such as training errors; flexibility and strength in associated areas i.e. the rest of the lower limb, pelvis and spine; running technique, footwear and triathlon specific causes (see section on cramping below).
Calf muscle cramping
Cramping is an interesting topic. It seems that muscle fatigue is being establised as the major cause of exercise induced muscle cramping. If you would like to know more about the science behind muscle cramping have a look at The Science of Sport blog. There are a few reasons why triathletes might be more likely to develop cramping in the calf muscles than other athletes. The prolonged planter flexed (toes pointing) position held in the swim could result in muscle fatigue. Add to the mix cold water and the increased muscle tension generated in order to help maintain core body temperature and cramping could certainly become a risk. Cramping can also occur on the bike. A cleat position that is too far forward can increase the load on the calf. Likewise a saddle that is too high causing you to plantar flex excessively at the bottom of the stroke could increase the risk of cramping. On the run, fatigue is the most obvious cause, having completed two disciplines already. A change in running technique too, for example changing from a heel strike pattern to more of a mid-foot or forefoot strike pattern, will increase the demand on the calf and initially could cause early fatigue and cramping or muscle strain until you adapt to the new technique.
When a cramp does occur a sustained stretch of the muscle will often ease the cramp allowing you to continue. However, some cramps can be so severe that they cause a muscle strain or the cramp may recur as you attempt to continue. At this point you will have to decide if you can continue or not. Teaching your body to resist fatigue through appropriate training, such as strengthening the calf and associated areas through both specific strength exercises and also training strategies such as hill work and over-gearing (riding in a higher gear than you would normally either on the flat or hills) and providing your body with adequate nutriation and hydration will help prevent cramping.
Brick sessions, practicing one discipline immediately followed by another, are a great way to teach your body to cope with the physiological demands of triathlon. A lot of novices struggle with the bike to run transition initially. Brick sessions are an essential part of any triathlon training program especially in the build and race periods.
Referred pain from the lower back
The lumbar spine (lower back) can refer pain into the calf. Referred pain is pain felt in an area that is remote from the area causing it. A number of structures in the lumbar spine, for example intervertebral discs and facet joints, can result in pain in the calf. In addition sciatic nerve related pain can be felt in the calf. Bike set-up is important here because the aero-position a lot of triathletes adopt can place excessive tension on the sciatic nerve and other neural structures.
In this case, the lumbar spine rather than the calf needs specific treatment. Restoring flexibility and strength to the affected area, making postural adjustments, modifying bike position and mobilising the neural tissue e.g. sciatic nerve, are likely to help.
Delayed onset muscle soreness
Delayed onset muscle soreness (DOMS) is common after prolonged or unaccustomed activity. Your first training session after a period of time off, your first speed session or your first hill session could all result in DOMS. The pain tends to peak 24-48 hours post-exercise and then eases. Light aerobic exericise and avoiding eccentric loading (when the muscle is lengthening under load e.g. walking down hill), have been shown to help. Anecdotally stretching seems to help but there is little scientific evidence to support this. Thanks to the phenomenon known as ‘muscle memory’ your second session of the same exercise is unlikely to cause you as much pain!
Recurrent Exertional Compartment Syndrome
Recurrent Exertional Compartment Syndrome (RECS), although not as common, is worth mentioning. The muscles in the lower leg are divided up into compartments. Each compartment is surrounded by fascia (connective tissue). During exercise there is an increase in blood flow to the working muscles. The increased blood flow results in the muscles swelling in size. If the fascia surrounding the compartment is too tight you will get a build up in pressure in that compartment. This will cause pain, can cause sensory changes e.g. numbess or tingling, reduced performance and potentially damage to the tissues. These symptoms will gradually build during a bout of exercise, building faster with exercise at higher intensities, and eases within minutes of ceasing exercise.
RECS is not so easy to manage. Some people will require surgery in order to to correct the excessively tight fascia surrounding the compartment. The recovery time is relatively quick and returning to activity quickly is very important. Stretching, deep soft-tissue massage, correcting training errors such as excessive volume and running technique changes may help depending on the severity of the problem. Sometimes activity modification is required e.g. a break from running may result in muscle atrophy (the muscle becoming smaller) and thus the tightness within the compartment is not such an issue and a gradual return to running may be possible.
Phew! That was a long one. Tim (LTFC Coach)