What shin splints are--or aren't
Here' s a conversation I can still recall from my school days. A fellow miler from the track team approached me and said, 'Hey, Anderson, how come you're always limping?'
Startled by the slur (for some reason, I had always assumed that my usual shuffling fell within the boundaries of normal walking and running), I racked my brain for the proper riposte. Suddenly, to my complete amazement, I heard myself mutter: 'I've got a bad case of shin splints' to the impudent oaf.
At the time, I actually had no idea what shin splints were but confidently assumed that they had to be an affliction of the legs. Since limping also involved the lower extremities, my retort possessed a certain amount of logic and suggested that there was some sort of medical reason for my awkward gait. To the alert listener, it also hinted that my condition was temporary in nature and that I would soon be running like Roger Bannister. After all, if I had said, 'Oh, my limp -my doctors say that my leg and foot bones are simply put together in a highly abnormal fashion,' the meaning of my response would have been quite different. Anyway, simply hurling abuse at the bonehead, another possibility, didn't seem like a wise move. I didn't want to develop neck and jaw splints to go along with my leg problems.
So, after hearing the stunning news about my legs, did my interrogator stumble away meekly, stammering apologies for prying into a delicate medical condition? Not at all. In fact, he wasn't the least-bit impressed by my pseudo-scientific explanation. He simply replied, 'Anderson, you haven't been working THAT hard!'
The rude fellow HAD put his finger on one of the key features of lower leg injuries: they ARE often associated with very vigorous training. His refusal to acknowledge the possible presence of shin splints was understandable in those ancient times (the conversation took place in 1965), when a simple mile still seemed like an unbearably long distance to run and most distance runners logged no more than 10-15 miles With injuries to the legs occurring so frequently, the term shin splints has today become an acceptable part of athletic parlance. Unfortunately, the term shin splints is a pretty ambiguous one; it's defined by the American Medical Association as an inflammation of the muscle, tendon, OR bone in the lower part of the leg. In other words, the term shin splints doesn't refer to any one precise problem. When you tell someone you have shin splints, you might as well just say that the portion of your leg below the knee hurts; you're not really saying what exactly is hurt or how you can correct the impairment.
Frequently, lower leg pain in athletes is transitory and responds well to simple treatments -rest, icing, relaxed stretching of the lower leg muscles, antiinflammatory medications, and compression and elevation if there is swelling. Usually, the pain gradually subsides, and an athlete is able to resume training within a few days. In other cases, however, the leg pain doesn't diminish, or it may seem to disappear only to re-announce itself whenever significant amounts of training are attempted. These longer-lasting problems shouldn't automatically be assumed to be shin splints. In fact, they are usually a result of one of three conditions - a 'compartment syndrome,' chronic tendonitis, or a stress fracture. Each malady produces its own specific signs and symptoms, and the treatments for these three disorders can be quite different.
Compartment syndrome is NOT caused by taking too many overnight train trips in cramped couchettes. In fact, compartment syndrome owes its name and origin to the fact that leg muscles are not arranged randomly as loose straps which run from bone to bone. In reality, the muscles are often grouped together into little sections of the leg which are enclosed by a tough wrapper of connective tissue. Such a muscle-connective tissue combination is called a compartment.
When you move from place to place as you engage in your sport, excess fluid can build up within one of these compartments, putting pressure on muscle fibres, nerve cells, and blood vessels inside the compartment and causing a great deal of pain. Frequently, the discomfort will be so severe that an individual will be forced to stop exercising. In addition, the pain will usually be accompanied by the two telltale symptoms of a compartment syndrome -numbness and weakness in the leg.
Numbness occurs because the excess pressure within a compartment hampers the activity of sensory nerves carrying messages toward the brain. The affected athlete may lose feeling in the 'web' of the foot (between the first and second toes), or the insensitivity may extend up the foot toward the ankle. Weakness is experienced because motor nerves carrying stimulatory impulses toward the muscles are also damaged by the pressure. If a compartment in front of the leg is involved, an athlete may have trouble 'dorsiflexing' the ankle (moving the foot and toes toward the shin), and the foot may seem to 'flop' loosely during running. In a posterior-compartment problem involving muscles on the back side of the leg, there is often weakness when an individual tries to push his/her body forward forcefully with the affected leg.
If you have a compartment syndrome, you will usually observe swelling in your lower leg which will tend to subside when the leg is elevated. The troubling syndrome can be most definitely diagnosed by a doctor who places a catheter into the compartment which seems to be affected and then monitors pressure within the compartment before, during, and after exercise. During this diagnostic test, the patient usually runs for a long-enough time to produce pain.
How do you deal with compartment syndrome? Some compartment syndromes can be alleviated by avoiding all workouts for at least four weeks and then gradually returning to training. Cryotherapy, stretching, and strengthening exercises are employed therapeutically during this recovery period. If you don't respond to these simple measures, a fasciotomy -a surgical incision into the connective-tissue wrapper surrounding the muscles -can be performed to relieve the pressure inside the compartment. There has been some controversy concerning the effectiveness of this surgical procedure, though, with some skeptics arguing that fasciotomies can induce muscle weakness and don't always reduce the excess pressure.
However, a team of Canadian researchers recently performed fasciotomies on 25 individuals (14 males and 11 females) who were suffering from chronic compartment syndromes. After surgery, 22 patients obtained excellent relief from their leg pains and were able to resume their normal athletic activities, implying a high effectiveness for the surgical intervention. Usually, training can resume fairly quickly after a fasciotomy -most often within one to three weeks.
Many instances of lower leg pain are due to stress fractures, which are small-scale breakdowns in bony tissue. In fact, the tibia, the principal bone in the lower part of the leg, is the site of about 50 per cent of all stress fractures in athletes. As an area within a bone which has been damaged by repetitive impact forces, a stress fracture is worrisome because it can lead to an actual dislocation fracture, and its presence may also signal an underlying nutritional problem (inadequate intake or absorption of calcium) or hormonal problem (too- low levels of sex hormone).
Stress fractures can also be troubling to diagnose. Regular X-rays quite often fail to detect them, so a more costly procedure called a bone scan may be needed to confirm the presence of traumatised bony tissue. In a bone scan, mildly radioactive material is injected into the blood. Bone which is remodelling and rebuilding itself at the site of a stress fracture will accumulate more of this infused radioisotope, and the affected bony area will show up as a dark splotch on a 'scintigram.' Although it's often said that stress fractures take two to three months to heal, in reality six months may be required to restore the bone to normal and remove most traces of pain, and some patients require two years for a full recovery.
How to spot the difference
How can you tell if you have a stress fracture instead of a compartment syndrome? Ordinarily, the pain emanating from a stress fracture is quite different. Sometimes called 'crescendo pain,' stress-fracture pain tends to build up gradually as you exercise, beginning as an annoying irritation during the first few minutes of your workout and becoming a throbbing torment as you continue to train. There is usually little of the numbness, weakness, and swelling associated with compartment syndromes, and pain is usually not present when the athlete is at rest. Sometimes, there is a specific point of tenderness in the lower leg, often felt on the inside of the calf when deep pressure is applied with the fingers. Often, the bone will actually hurt when it is tapped near the damaged area, and occasionally a hard nodule will appear on the surface of the bone at the trouble site.
An athlete who develops a stress fracture shouldn't just rest until symptoms of the fracture are mollified and then blithely resume training. The bone deterioration could be the result of using non-cushioning training shoes, exercising on very hard surfaces like concrete, or overtraining, but it could also be the result of poor nutrition (lack of calcium in the diet or impaired absorption of calcium), so a complete analysis of the athlete' s diet should be carried out. And athletes with stress fractures should also make certain that sex-hormone levels are okay (adequate testosterone levels in males and oestrogen concentrations in females are necessary for optimal bone maintenance).