Shin splints: lower leg strengthening exercises for prevention and treatment

 

Like so many athletes, you started this year with great intentions. You took your workouts to a higher level, doing more than you had ever done before, and things were great for a couple of weeks. Your fitness began to rise to new heights. Unfortunately, after a series of particularly strenuous workouts, you felt a dull ache on the inside, lower portion of your shin as you began a workout. The discomfort went away once you had warmed up, though, so you were not overly concerned.You forgot about the little ache, but it didn’t forget about you. On the following day, the pain returned - and lasted for a longer portion of your workout. As the days went by, pain was present throughout your training sessions as well as your cool-downs - and even hung around during regular daily activities. When you used your fingers to probe the area near the back, inside edge of the lower part of your tibia (the main bone in the lower leg), you felt tenderness but no major swelling, and the pain seemed to centre in the tissues (muscles and tendons) near the tibia, not the tibia itself. What was wrong?

Running athletes are particularly vulnerable to splints

Of course, you had developed a classic case of ’shin splints’, an injury which is technically known as medial tibial stress syndrome (MTSS). Athletes involved in sports that involve running and jumping (including soccer, cricket, basketball, rugby, volleyball, endurance running, sprinting, and triathlons) are particularly vulnerable to MTSS, and many experts believe that shin splints are the most common injury in endurance runners; indeed, research shows that up to one-in-five injured runners are ’on the shelf’ because of MTSS(1). MTSS is an especially troubling injury, because it can stop quality training in its tracks, and it also tends to recur, defying conventional treatments. The actual site of injury in the shin area can be muscle, tendon, bone, or the connective-tissue wrappings which surround muscles and bones.

Some sports-medicine experts contend that MTSS is almost inevitable in sports that involve running, since each shin absorbs a force equal to 2-3 times body weight with every footfall - almost 100 times per shin per minute. The cumulative effect of this repetitive stress on the muscles and connective tissues in the shin area is believed to be the origin of MTSS. For that reason, MTSS is often called an ’overuse’ injury although, as you’ll see, the real problem is not so much overuse as lack of preparation for use. Specifically, MTSS occurs because the ankle dorsiflexors - the shin muscles which, in effect, pull the top surface of the foot towards the shin and also (as part of their eccentric functioning) keep the foot from being pulled away from the shin too rapidly - are not functioning as well as they should.

Slapping sounds on the pavement

The key role of these ankle dorsiflexors during running is, in fact, to control and limit plantarflexion - the movement of the foot away from the shin. During the very earliest part of the footstrike portion of the gait cycle - as the foot first makes contact with the ground - there’s a tendency for the foot to slap hard against terra firma. Even in a ’heel-striker’ (an athlete who first makes contact with the ground with his heel), forward momentum tries to slap the front-bottom portion of the foot against the ground very quickly and forcefully after heel contact. In either case (heel or forefoot striking), there is a potentially uncoordinated and energy-wasting slap-down of the foot which is resisted by eccentric contractions of the dorsiflexor muscles in the shins (eccentric because the poor shin muscles are trying to contract while they are being rather dramatically stretched).

If an athlete has weak ankle dorsiflexors, you can often ’hear him coming a mile away’ if he is running on a road, because his feet actually make fairly loud slapping sounds against the pavement. Of course, such an athlete will be at high risk for MTSS, because the rapid downward movements of his feet which are creating the hubbub will tear at and overstress his dorsiflexors. By contrast, the runner with strong, functional dorsiflexors will seem to pad softly along, even if he is running fast on rock-solid concrete.

The slower the runner, the louder the footfalls

To learn a lesson about the merits of excellent shin-muscle strength, simply go to a 10km road race which has both a large and an elite field. Station yourself about four miles out on the course and listen to the elite runners as they go past. Continue listening as the rest of the field unfolds before you, and note that as the runners slow down their footfalls become louder. This is not just because there are more middle-and-back-of-the-packers than there are elites, and it is the exact opposite of what should occur: ground-reaction force is a function of running speed, so the elites are hitting the ground harder and should be making more sound. Their quietness is a testament to their efficient, coordinated, shin-muscle actions, which make them not only very quiet but also very fast.

Watch some of the elite Kenyans running, for example, and compare their foot-to-ground patterns with those of elite Brits or the ’average Joe’. The Kenyans build up tremendous dorsiflexor strength and functionality because they spend their early years running and walking endless miles barefoot, rather than having their feet clamped onto a fluffy set of midsoles which shield the feet and ankles from hard work (or, worse still, sitting around with legs propped up on soft cushions). As a result, the Kenyans waste very little energy during the stance phase of the gait cycle and seldom hobble off the track or roads with shin injuries. They don’t slap the ground; rather their legs react with the ground like tightly coiled springs.

Why many exercises don’t work

In addition to controlling plantarflexion, the dorsiflexors must deal with side-to-side motions of the foot and ankle during running, as well as the rotational motions which are a natural part of the gait cycle. Any tendency of the foot to pronate or supinate must be controlled by the shin muscles. If there is relentless, stressful motion in any direction, the shin muscles can be damaged. That’s why many of the exercise routines that supposedly prevent shin splints don’t work so well; they often emphasise only front-and-back motions, rather than the side-to-side and rotational activities which are routine aspects of the biomechanics of running. The bottom line is that if you want to prevent shin splints, you can’t merely develop general strength in your dorsiflexors, or strength that exhibits itself in only one plane of motion: your dorsiflexors must actually be stronger while you are running.

The exercises that do work

That’s why the classical mode of treatment for shin splints, RECEIPT (rest, elevation, compression, easy stretching of the muscles, icing, and possibly taping) works fairly well at relieving symptoms but does a very poor job of keeping the injury from recurring. Only by improving the functional strength of the dorsiflexors and the strength and coordination of the entire ankle area can MTSS be held reliably at bay. If your dorsiflexors are strong enough to handle your total training load and are not yanked around too badly by poorly controlled ankle movements, your training year should be unmarked by the pain and disruption of shin splints.

To reduce your risk of MTSS, use the following protective exercises:

1. Wall shin raises

a. Stand with your back to a wall, with your heels about foot-length from the wall. Then, lean back until your buttocks and shoulders are resting against the wall;
b. Dorsiflex both ankles simultaneously while your heels remain in contact with the ground: bring your toes as close to your shins as you can, then lower your feet back towards the ground, but do not allow your forefeet to actually contact the ground before beginning the next repeat;
c. Complete 12-15 reps of the above;
d. Maintaining your basic position with your back against the wall, dorsiflex your ankles to almost their fullest extent, then quickly dorsiflex and plantarflex your ankles 15 times over a very small range of motion.These short, quick ankle movements are called pulses;
e. As you gain strength over time, make the exercise more difficult by progressing from one set of 15 reps (of both basic raises and pulses) to two and then to three, walking around for 15-30 seconds between sets if you wish.

Once you can quite comfortably complete 3 x 15 of the double-leg raises (both basic and pulsing), progress to the single-leg wall shin raise, as follows:
f. Start in the same position as before, but with only one foot in contact with the ground, while the other rests lightly on the wall behind you. Now your full body weight is on one foot - as it is during running - and the exercises are considerably more difficult;
g. Begin with 12-15 reps per foot (both for the basic exercise and pulses) and progress to 3 x 15 on each foot as your strength increases. There’s no need to rest between sets; simply carry out 15 reps plus pulses on one foot, shift over to the other foot, and so on until you have completed three sets with each foot.

Although wall shin raises are a great routine for the shins, they are not quite as running-specific as the exercises which follow.

2. Heel step-downs

Simple but devastatingly effective exercises for preventing MTSS.
a. Begin with a natural, erect body position, with your feet about shoulder-width apart, then step forwards with one foot. The length of the step should be moderate, as with normal walking;
b. When your heel makes contact with the ground, stop the foot from fully plantarflexing by using your shin muscles to keep the sole of the foot from making contact with the ground. After heel contact, the ball of your foot should descend no more than an inch towards the floor or ground, held in check by the eccentric contractions of your dorsiflexors (shin muscles);
c. Return your foot to the starting position (back by the other foot), and repeat this basic stepping action a total of 15 times. Then repeat on the other foot;
d. As with the wall shin raises, progress to three sets of 15 reps over time.

Once you have mastered the basic heel step-downs, try the same exercise with dramatically longer steps, which will increase the accelerating forces placed on the dorsiflexors and force them to work more forcefully and quickly, as they must do during running. Start with one set of 15 reps of long steps per foot and progress to 3 x 15 on each foot over time.

Finally, you will be ready to carry out the heel step-downs from a high step, which will increase the forces on your shin muscles to the greatest extent and, of course, build the greatest amount of strength. Use a bench or exercise platform which is about 4-6 inches off the ground. Apart from beginning each step from a bench, your movements are the same as with the basic step-downs, the idea being to land on the heel of the forward foot, then use the shin muscles to prevent the sole of the foot from making contact with the ground (again, don’t let the ball of the foot move downwards by more than an inch). The actual length of the step is moderate at first (you can progress to long steps later). As before, begin with 15 reps per foot, and progress to three sets of 15 reps as you gain strength and coordination.

Both the wall shin raises and heel step-downs can be carried out 3-4 times a week, along with your other strength-building exercises. You can perform them more often if you’ve had lots of problems with MTSS in the past, but not to the point of pain. Once you are an accomplished wall-shin-raiser and heel-step-downer, move on to the next two exercises, which are the ultimate MTSS preventers.

3. Heel hops

a. Using erect but relaxed posture, standing on your right foot, with your right knee just slightly flexed and your left knee flexed to about 90¡ so that the foot is completely off the ground;
b. Hop forwards on your right foot, but instead of landing in the mid-foot area, land on your right heel and hold the position for about two seconds, keeping the rest of your foot off the ground;
c. Repeat on the same foot 14 times more, then repeat on the other foot.

Initially, the hops should be just 4-6 inches in length, but you can increase the hopping distance as your strength and coordination improve. Another key progression is to gradually build up your speed of heel hopping, so that you are moving forwards quite quickly, while remaining on your heels. You can gradually move up to 3 x 15 hops per leg (or even more), but the ultimate progression is to carry out the exercise on a slight downward slope (initially just 1-2%). Using the slope will put severe pressure on your shin muscles, so be careful to begin with a modest number of reps.

4. Heel running

a. Start in a comfortable position, using relaxed and upright posture with your feet roughly beneath your shoulders;
b. Begin jogging slowly, allowing only your heels to make contact with the ground. Stay relaxed as you do this, and avoid the natural tendency to look down at your feet to see what is happening.
At first, keep your movements slow and jog for just 10 metres or so, but as you become more skilled your can speed up your heel running and go for about 3 x 20m, with a short break inbetween reps. Ultimately, you’ll want to be able to do some of your heel running on a very modest downward slope. The overall idea is to keep your ankles significantly dorsiflexed as you run and permit just a little plantarflexion with each heel-fall, allowing only your heels to make contact with the ground.

How to use your warm-ups to strengthen your shins

You can also incorporate the following shin-splint-preventing routines into the warm-ups which precede your regular workouts. The exercises develop shin-muscle strength and resilience as well as overall ankle coordination. Performing them before a training session transforms your warm-ups from humdrum routines into important strength-and-coordination sessions. Here’s what to do:

1. Walk on your toes

a. Walk on tiptoe as high as possible with your toes pointed straight ahead for about 20m. Your legs should be relatively straight and your steps initially small;
b. Repeat with your toes pointed outwards. Your legs should rotate outwards from the hips when you perform this movement; don’t simply turn each foot at the ankle - the whole leg must be involved;
c. Finally, repeat with your toes pointed inwards, rotating the entire leg in from the hip, not just the ankle;
d. Repeat each step at least once more before progressing to the next exercise.

2. Walk on your heels

a. Walk on your heels with your toes pointed straight ahead for about 20m, getting as high up on your heels as you possibly can. As above, keep your legs relatively straight and your steps small;
b. Repeat with toes pointed outwards then inwards, as with the previous exercise;
c. Repeat the whole sequence at least once more.

As the toe and heel walks become easy for you, graduate to doing the three variations of each exercise while jogging lightly, instead of walking, using a padded or grassy surface at first.

3. Skip for 20m

Landing in the mid-foot area with each contact with the ground, with toes pointed straight ahead. Repeat with toes pointed outwards, then again with toes pointed inwards. Repeat the whole sequence at least once more.

4. Skip high on your toes

For 20m, first with toes straight ahead, then pointed out, then pointed in.

Once the toe skipping exercises are comfortable, try some light skipping on your heels. Gradually build up your ability to heel-skip with toes straight ahead, pointed out, and pointed in for 20m at a time. Heel skipping is a great way to build dorsiflexor strength, but do it only on a padded or grassy surface to avoid impact injury to your heels.

5. Rhythm bounding

This doesn’t mean leaping along with extra-long strides, at least not at first, but jogging along with very springy, short steps, landing on the mid-foot area with each contact and springing upwards after impact. As you rhythm bound, your ankles should act like coiled springs, compressing slightly as you make your mid-foot landing and then recoiling quickly - causing you to bound upward and forward.
a. Move along for 20m-or-so with these quick, little spring-like strides, alternating right and left feet as you would during running;
b. After 10-20m of regular jogging, rhythm bound for 20 more metres, alternating three consecutive spring-like contacts with the right foot with three with the left;
c. After 10-20 more metres of regular jogging, close the set by bounding along for the full 20m on your right foot only, followed by 20m on the left (making sure that you land on the mid-foot area with each ground contact and that your ankle area, not your knee or hip, is doing most of the work).
Make sure, at least at first, that all of this is done on a padded surface or soft grass. As you become stronger and more skilled, you can increase the length and height of each bound and include additional sets of bounds, up to a maximum of four.

6. Dorsiflexion bounces

Jump vertically 10 times at close to maximal height, landing in the mid-foot area with both feet and then springing upwards quickly after each contact with the ground. The interesting part of this exercise is that you should dorsiflex your ankles - pulling the tops of your feet toward your shins - on each ascent, plantarflexing your ankles just before making contact with the ground. Rest for 10 seconds or so, then repeat. Over time you can add additional sets and increase the number of reps to 30. When you are really strong and skilled, try this exercise on just one foot at a time.

7. Rhythm bouncing

Rhythm bouncing is actually just jumping around, but what jumping!

a. Start with 10 jumps on-the-spot, moderately fast, to a medium height and with maximal motion at the ankles, but little flexion and extension at the knees and hips. Over time, you can work up to 30 jumps;
b. After resting for a few seconds, reduce the height of your jumps to less than an inch and complete 20 as fast as possible, minimising impact time as if landing on hot coals! Again, almost all of the action should take place at your ankles, not at your knees and hips. As you become more skilled, work up to 40 quicksilver jumps without stopping;
c. After resting for a few seconds, complete five ’high-impact’ jumps, reaching as high as possible. Over time, work up to 30 of these maxi-jumps;
d. Now make things interesting by jumping forwards and then backwards as quickly as possible, with a total of 20 ground contacts;
e. Rest for a few seconds, then jump from side to side for a further 20 contacts;
f. Rest again, then jump diagonally forwards, first to the right, then to the left, in zig-zag fashion for 20 contacts. Remember to use your ankle muscles to propel you, not the big muscles at the knees and hips.

As you gain in skill and strength, you can increase the number of sets of each type of rhythm bouncing from one to three, and then - the fun part - carry out each type of bouncing on one foot only. Moving in different directions as you bounce increases the ability of your shin muscles to handle all the forces created during running: the side-to-side and rotational stresses as well as the front and back forces.

Something has to give

Of course, carrying out these exercises doesn’t mean that your risk of MTSS will drop to absolute zero. If you suddenly up your weekly training volume from four to six hours, something will have to give, and it might well be your shin muscles and tendons. So be careful to avoid dramatic changes in the frequency, volume, or intensity of your training; always progress gradually to more difficult levels of work.

Sports-medicine experts often recommend stretching the ankle area by slowly moving the ankle to each end of its range of motion in the straight-back and straight-ahead plane (ie fully dorsiflexed then fully plantarflexed), holding each position for anything from five to 60 seconds. The problem with that, of course, is that you are stretching the muscles in only one plane of motion and thus not adequately mirroring the actions of running. At the very least, you should also stretch each ankle by fully rotating it outwards and inwards and also by plantarflexing and dorsiflexing the ankle while the foot is pointed both outwards and inwards to various degrees, not just straight ahead.

The experts also recommend strengthening the ankle area by adding resistance to the above stretching movements by the use of surgical tubing or elastic bands. That is a good way to increase general strength in the ankle, and it will certainly make you stronger when you carry out surgical-tubing exercises in the future. The problem is, of course, that you run with your feet on the ground, not poised in the air in the clutches of elastic bands. To fully prepare your ankles and shins for the rigours of running, you’re better off focusing on the specific exercises recommended in this article.

Does stretching actually help to prevent MTSS? There is no scientific evidence to prove this, but the idea is a logical one since over-taut muscles seem more likely to be damaged by pulling forces than relaxed fibres. Don’t stretch your ankle area until after your muscles are warm and flexible, however; a good time would be after a thorough warm-up or even at the end of your training session.

What about other lower-leg injuries?

Of course, not all problems in the lower leg are due to MTSS. Two other conditions in particular can sometimes be confused with shin splints, namely compartment syndrome and tibial stress fractures.

Compartment syndrome is so called because the leg muscles are often grouped together into little sections or compartments, each enclosed by a tough wrapper of connective tissue. During the act of running, excess fluid can build up within one of these compartments, putting pressure on muscle fibres, nerve cells, and blood vessels - and also causing a great deal of pain. Frequently, the pain is severe enough to halt a workout or even a race. And it is usually accompanied by the two telltale symptoms of a compartment syndrome - numbness and weakness.

Numbness occurs because the excess pressure within a compartment hampers the activity of sensory nerves carrying messages to the brain. As a result, the runner with compartment syndrome may lose feeling in the ’web’ of the foot - between the first and second toes - or higher up the foot, towards the ankle.
Weakness is a feature because motor nerves carrying impulses towards the muscles are also damaged by the high pressures within the compartment. If a compartment in the front of the leg is involved, a runner may have trouble dorsiflexing the ankle, and the foot may seem to flop loosely. In a posterior-compartment problem involving muscles in the back of the leg, there is often weakness when an individual tries to ’toe off’.

If you have a compartment syndrome, you will usually notice swelling in your lower leg which tends to subside when your leg is elevated. A doctor can diagnose the problem for certain by placing a catheter into one of your compartments and measuring pressure before, during and after running - usually to the point of pain.

And stress fractures?

These are small breakdowns in bony tissue, and tibial stress fractures, which are sometimes confused with MTSS, are the most common of all stress fractures in athletes, accounting for about 50% of the total. In addition to producing a lot of pain, stress fractures can actually develop into dislocation fractures, in which two parts of the bone actually separate. Stress fractures also may be ’warning signals’ highlighting an underlying nutritional or hormonal problem.

Unfortunately, traditional X-rays often fail to detect stress fractures, so a more costly bone scan is often needed to confirm the diagnosis. With this procedure, radioactive material is actually injected into the blood; bony tissue which is remodelling and rebuilding itself at the site of a stress fracture will accumulate more of this infused radioisotope, causing the affected bony area to show up as a dark patch on a ’scintigram’. While it’s often said that stress fractures take 2-3 months to heal, it can take up to six months to restore the bone to normal and remove most traces of pain, and a few athletes take more than a year to recover completely.

The discomfort associated with stress fractures, sometimes called ’crescendo pain’, tends to build up steadily during running, starting as an irritant and developing into a throbbing torment as an athlete continues to run. There is usually little of the numbness, weakness, and swelling associated with compartment syndrome, and pain does not usually persist when an athlete is at rest. Often the bone will hurt when it is tapped near the damaged area, and sometimes a hard nodule appears on the surface of the bone at the site of the trouble.

If you’re diagnosed with a stress fracture, you should be sure to have a nutritional analysis carried out, since your problem could be the result of inadequate calcium intake or poor calcium absorption. In addition, athletes who develop stress fractures should have their sex-hormone levels checked since adequate testosterone concentrations in males and oestrogen levels in females are required for optimal bone maintenance.

Telling one from the other

How can you differentiate MTSS from stress fractures and compartment syndromes? The pain of MTSS is usually less localised than that of stress fracture (tending to run up and down a region of the lower leg near the tibia) and usually can’t be produced merely by tapping on the tibia. In addition, MTSS produces none of the numbness associated with compartment syndromes.

If you are unfortunate enough to come down with MTSS, your recovery period will usually last from one to six weeks, depending on how severely you are stricken. If you have a mild case (your shin hurts moderately, and only after workouts), you should immediately cut your training volume by about 30% and start doing the protective exercises recommended above. Start easily with only one set of each exercise, and stop if you feel any pain. Ice the affected area down thoroughly after activity, and of course keep the whole area as loose and flexible as possible. Within a week or two, you should be able to get back to your normal training, but be sure to carry on with the protective exercises.

If you have a somewhat tougher case of MTSS (mild pain crops up during workouts but doesn’t seem to slow you down much), trim weekly training volume by around 50%, ice and stretch religiously, consider taking non-steroidal anti-inflammatory drugs (NSAIDS) - but only if you are not prone to the gastrointestinal upsets which have been linked with these compounds, and become a devotee of our shin-strengthening exercises (starting gradually since they can further inflame tender shins if overdone). Use cycling workouts to maintain fitness, and in 2-3 weeks, you should be ready for regular training.
If your MTSS produces sharp pain while you are training, stop all workouts, ice and stretch, take NSAIDS as directed by your doctor and - when pain subsides - begin using our exercises systematically, starting with a few two-legged wall shin raises at first and gradually progressing to the others. Use an exercise bike to maintain fitness, and return to normal training in 4-6 weeks.

Remember that if you carry out our shin-splint routine several times a week and refrain from making bizarre and sudden changes in your training, your encounters with MTSS should drop to a very low rate. Best of all, however, you will have unbelievably strong shin muscles, and as a result you will run much more quietly - and of course much more quickly, too!

Owen Anderson