A stress fracture is an overuse injury that occurs when the fatigued muscles, which are unable to absorb any added shock, transfer the overload of stress to the bone. This results in a tiny crack called a stress fracture. Most stress fractures occur in the weight-bearing bones of the lower leg and the foot. More than 50 percent of all stress fractures occur in the lower leg. Women athletes are more likely than men to experience stress fractures due to osteoporosis. Flat feet or high, rigid foot arches can increase one’s risk of a stress fracture.
Stress fractures are often the result of increasing the amount or intensity of an activity too rapidly. They can also be caused by the impact of an unfamiliar surface, such as when a tennis player switches playing surfaces from a soft clay court to a hard court; improper equipment, such as when a runner uses worn or less flexible shoes; and increased physical stress, such as when a basketball player substantially increases his or her playing time. Studies have shown that athletes participating in tennis, track and field, gymnastics and basketball are very susceptible to stress fractures. In all of these sports, the repetitive stress of the foot striking the ground can cause trauma. Without sufficient rest between workouts or competitions, all athletes are at risk for developing a stress fracture.
There are also wide variety of factors commonly linked with the risk of stress injuries to the bone:
Age: The risk appears to grow with increasing age as the bone in older individuals is less resistant to fatigue. The risk is also linked to declining fitness
Training errors: Commonly, stress fractures appear after a change in activity and an increase in running mileage and intensity. Excessive running on hard surfaces that absorb force poorly, and running on crowned roads which cause an unequal distribution of weight within the foot, have been implicated. If, after a lay-off, training is resumed at the same volume and intensity, the athlete will be at an increased risk of developing stress fractures. Beginners are similarly at risk
Fitness history: It is suspected, though not proven, that the most sedentary and least fit people entering a sports programme are more likely to get stress fractures. Gradual increase in training loads is important
Footwear: Gardner and colleagues (1988) reported that the cost of training shoes (expensive versus inexpensive) made no difference in the incidence of stress fractures in Marine recruits. The one significant factor linked with stress fractures during recruit training was the running shoe age. Those who wore newer shoes developed fewer fractures
Endocrine status: Peak bone mass may be jeopardised in prolonged amenorrhoea (absence of menstruation). Women athletes suffering from amenorrhoea are at especially high risk, more so if their diets are low in calcium. Although studies show that bone density in cortical bones tends to be normal among amenorrhoeic female athletes, these still remain the prime sites for stress fractures. Grimston and co-workers (1991) have shown that runners who began running training in close association with the age of menarche demonstrate a higher incidence of stress fractures than those commencing training at a later age. Heavy endurance training may also compromise androgen status in men, which may lead to lowered bone strength. At present, little is known about this relationship
Nutritional factors: Training, nutritional and hormonal factors tend to be closely interlinked with stress fractures (see Peak Performance no. 59, 1995, pp 4-7). Recommended calcium intake in post-puberty is 800mg/day, whereas stress-fracture patients are encouraged to consume 1500mg of calcium daily
Biomechanical factors: Most research has been done among military recruits, and the findings have shown that biomechanical factors, involving anatomical variation, have an important role in the development of stress fractures. Gilati and Abronson (1985) showed that tibial torsion (twisting/bending of the tibia) and the degree of external rotation at the hip were associated with the incidence of stress fractures. When neither were present, the incidence of stress fractures was 17 per cent, but when both were present, the incidence increased to 45 per cent. The assessment of these types of ‘faults’ generally requires sophisticated equipment which unfortunately is not readily available. Other factors linked with the occurrence of stress fractures include: high arched foot, excessive pronation (turning inward) or supination (turning outward) of the foot, longer second toe and bunion on the great toe. All of these will alter the mechanics of running and consequently impose abnormal stresses on adjacent structures and, eventually, the bone.
Stress fractures usually have a narrow list of symptoms. It could present as a generalized area of pain, tenderness, and pain with weight-bearing. Usually when running, a stress fracture has severe pain in the beginning of the run, moderate pain in the middle of the run, and severe pain at the end and after the run.
Symptoms of a stress fracture include a specific painful spot that feels worse when pressure is applied, pain that increases over time, pain that decreases with rest and increases with activity and possibly swelling. The skin surrounding the area may or may not be tender to the touch. An athlete may not even notice a stress fracture when it happens, and the pain may not start until days later.
There are also two theories about the origin of stress fractures. The ‘fatigue theory’ suggests that during repeated efforts (as in running), the muscles become unable to support the skeleton during impact as the foot strikes the ground. Instead of the muscles absorbing the shock, the load is transferred to the bone. As the loading surpasses the capacity of the bone to adapt, a fracture develops. The ‘overload theory’ suggests that certain muscle groups contract in such a way that they cause the attached bones to bend. After repeated contractions and bending, the bone breaks.
Stress fractures are probably preceded by periostitis (inflammation of connective tissue covering the surface of bone), causing bone pain and pain during exercise. Management of shin splints involves rest; if the symptoms still persist after two weeks, a stress fracture is suspected. When the pain has persisted for six weeks or more, a stress fracture is the likely cause. In about half of the cases, symptoms start appearing slowly, while in the other half they appear without warning. First, pain is felt during training but not at rest. With continued training, pain increases as the intensity increases. Pain will persist after exercise, and at some point localised swelling and tenderness are apparent at the fracture site. Stress fractures are not seen initially on X-ray, which makes diagnosis difficult. The treatment of stress fractures involves rest from usual weight-bearing activity for about four-to-eight weeks, and until the pain has gone
If a stress fracture occurs in a weightbearing bone, healing will be delayed or prevented by continuing to put weight on that limb.
Rest is the only way to completely heal a stress fracture. The average time of complete rest from the activity that caused the stress fracture is one week. A fracture requires 4 to 8 weeks of recuperation, however, which may include no more than light use of the injured body part, as long as activity does not cause pain. After the recuperative period, another 2 weeks of mild activity without any pain may be recommended before the bone may be safely considered healed and activity may gradually increase.
During this time, it is advised that training errors be identified (for instance, too much, too soon) and avoided in the future. One rule of thumb is to not increase the volume of training by more than 10% from one week to the next.
Rehabilitation usually consists of muscle strength training to help dissipate the excessive forces transmitted to the bones.
One method of avoiding stress fractures is by adding more stress to the bones. Although counter-intuitive given that stress fractures are caused by too much stress on the bones, when moderate stress is applied to the bone in a controlled manner, the bone becomes stronger and less susceptible to a stress fracture. An easy way to do this is to follow one widely known rule for runners, which states that mileage should be increased by no more than 10% per week. This allows the bones to adapt to the added stress so they are able to withstand greater amounts of stress in the future.
Strengthening exercises also help build more muscle strength in the legs. Strengthening these muscles will stop them from getting fatigued so quickly, which allows them to absorb the pounding of running for longer periods of time. Key muscles that need to be strengthened with lower leg stress fractures are the calves and the shin muscles.
Depending on a variety of factors including weight, running surface and shoe durability, runners should replace their shoes every 300-700 miles to allow adequate mid-sole cushioning. A change in the choice of running surfaces can also help prevent stress fractures.
When performing any exercise that applies more stress to the bones, it may be wise to increase calcium and vitamin D intake, depending on the individual. Also, it is important to monitor foods eaten because nutrition plays a vital role in bone development. Certain individuals are at risk of osteoporosis, and depending on the country in which medical care is being supplied, there may be a screening program in place
Runner’s Knee is a condition characterized by pain behind or around the kneecap. Poor kneecap tracking is believed to be the main cause this condition. The kneecap (patella) slides over a groove on the thighbone (femur) as your knee bends and straightens. If, for example, the front thigh muscles (quadriceps) are weak or imbalanced, the resulting muscle imbalance can pull the kneecap to the left or right of the groove, causing pressure, friction, and irritation to the cartilage on the undersurface of the kneecap when the knee is in motion.
Muscle imbalances / weakness or inflexibility in the muscles that support the knee, and mechanical errors can cause poor knee tracking. There may be multiple factors involved.
Quadriceps (front thigh muscles) strengthening exercises are considered to the most important exercise, in most cases, for correcting poor knee tracking. The quadriceps controls the movement of the kneecap. (They are attached to the kneecap and then to the top of the shine bone by tendons).
Sometimes the quads (there are four divisions) are imbalanced. The inner quad pulls the kneecap inwards and the outer quad pulls the kneecap outwards. If the inner quad is weak, the stronger outer quad tends to pull the kneecap off center. In this case, exercises to strengthen the muscles of the inner quadriceps are particularly helpful
Another imbalance can occur when the muscles in the front of the thigh are significantly stronger than the muscles in the back of the thigh (the hamstrings). If your hamstrings are weak, your quads have to work harder. Tight hamstrings cause increased pressure between the patella and femur.
Tight Iliotibial Band:
The iliotibial band (a fibrous band of tissue on outer thigh that extends from the hip to below the knee) also affects knee stability. If too tight, this muscle/tendon of the outer thigh can pull the knee to one side. A tight iliotibial band can also cause Iliotibial Band Syndrome.
Weak Hip Abductors:
The hip abductors (muscles on the outer thigh involved in moving leg to side) also help support the knee. Strengthening these muscles may also improve runners knee.
Muscle imbalances in the lower body, especially the quads are common. Tightness of the muscles and tendons can also pull the kneecap toward one side. In females, the increased inward slant of the thigh towards the knee is believed to the reason they are at higher risk of developing Runners Knee / Patellofemoral Pain Syndrome
Mechanical errors include misaligned joints in the foot or ankle; a kneecap that is located too high in the joint; flat feet / over pronation. Pronation is the normal inward roll of the foot as the arch collapses after heel contacts ground during walking or running. Over-pronation causes excessive internal rotation of the lower leg and knee.
Pain, typically diffuse pain, in front, around or beneath the kneecap. More pain and/or feeling of joint instability after climbing stairs, jumping rope, running, or after a period of sitting.
There is extra pressure between the kneecap and thighbone when the knee is bent at a right angle as when sitting. The kneecap is pressed towards the femur. If there is already irritation of the cartilage on the underside of the kneecap, discomfort or pain results. Even sleeping in a curled up position can cause pain when the condition has flared up. Contracting the quadriceps, as when going up or down stairs, also causes increased compression of the knee joint.
Sometimes after activities that have activated the quadriceps, it feels the knee is being pulled to one side. Sometimes a clicking, cracking or crunching sound is heard when the knee is bent or straightened. This is the kneecap slipping back into the groove.
Rest : (not total rest) Temporarily avoid activities that cause extra stress on the knees such as squatting/kneeling or high impact activities like running until the pain subsides. Swimming or low-impact activities such as working out on an elliptical trainer are fine. Avoid squatting/kneeling as a bent knee causes extra pressure between the patella and femur. Avoid leg presses where you support your weight with a bent knee. Straight leg lifts are safer. As you get stronger, partial squats are ok
Icing: Applying Ice to the knee, especially after exercise may reduce pain and swelling. Don’t ice for over 20 minutes at a time to prevent frostbite. Elevating the knee above the level of the heart while icing helps in reducing the inflammation.
NSAIDs : non-steroidal anti-inflammatory drugs such as Aspirin or Advil, as recommended by your doctor.
Exercise: Exercises, particularly exercises to strengthen and stretch the quadriceps (front thigh muscles) and hamstrings (muscles of the back of thigh). The exercises emphasized in the majority of cases are those that strengthen the quadriceps particularly the inner division of the quadriceps. This usually is very effective. Spending a few minutes, a couple of times a day on these muscles and gradually working up to 20 minutes per day are sometimes all that is needed. Be patient. It can take several weeks to notice an improvement.
Knee Taping : Taping is used to realign the kneecap and hold the kneecap in place. Although knee taping has not been scientifically proven to help stabilize the knee joint, it has been shown to significantly reduce pain. The relief is usually immediate. There are different techniques that a physical therapist (physiotherapist) can show you. The tape can be irritating the skin.
Knee Brace: a Patellar Stabilizing Brace helps keep the kneecap in the middle of the patellofemoral groove. This may be helpful when the muscles than support the knee are still weak. A knee brace can take some stress off the knee and help relieve pain. Wearing a brace does not replace the strengthening exercises that correct the root of the problem. Braces help some people more than others. (Wearing them during sports has not been shown to reduce knee injuries) They are expensive, and some people find them hot and bulky. Patellar stabilizing braces must be fitted properly to be effective. Not all knee braces are created equally. Ask a doctor or physical therapist whether or not knee braces are appropriate for your situation.
Proper Foot Wear: e.g. Shoes with an arch support to control over pronation, shoes with adequate cushioning in sole to help absorb shock. Orthotics may be required for those with severe over pronation. High heels throw your body forward and increase the pressure underneath your kneecap. Limit the time spent wearing high heels.
Surgery for Runners Knee should be a last resort, after an exercise program to correct muscle imbalances has been given a fair trial. It may be necessary if there are significant structural abnormalities.
A shin splint is pain resulting from damage to the muscles along the shin.
The usual cause is long-standing, repeated stress to the lower leg. Two groups of muscles in the shin are susceptible to shin splints. The location of the pain depends on which group is affected.
Anterolateral shin splints affect the muscles in the front (anterior) and outside (lateral) parts of the shin. This type of injury results from a natural imbalance in the size of opposing muscles. The shin muscles pull the foot up, and the larger and much stronger calf muscles pull the foot down each time the heel touches the ground during walking or running. The calf muscles exert so much force that they can injure the shin muscles.
Posteromedial shin splints affect the muscles in the back (posterior) and inner (medial) parts of the shin, which are responsible for lifting the heel just before the toes push off. This type of shin splint often results from running on banked tracks or crowned roads and can be worsened by rolling onto the outside of the feet (pronation) excessively or by wearing running shoes that do not adequately prevent such rolling
Anterolateral shin splints: The main symptom of anterolateral shin splints is pain along the front and outside of the shin. At first, the pain is felt only immediately after the heel strikes the ground during running, walking, skiing, or other similar exercises. If the person continues to run, the pain occurs throughout each step, eventually becoming constant. Usually by the time the person sees a doctor, the shin hurts when touched.
Posteromedial shin splints: The pain produced by this type of shin splint usually starts along the inside of the lower leg, about 1 to 8 inches above the ankle, and worsens when a runner rises up on the toes or rolls the ankle in. If the person continues to run, the pain moves forward, affecting the inner aspect of the ankle, and may extend up the shin to within 2 to 4 inches of the knee. The severity of the pain increases as the shin splint progresses. At first, only the muscle tendons are inflamed and painful, but if the person keeps running, the muscles themselves can be affected. Eventually, tension on the inflamed tendon can actually pull it from its attachment to bone, causing bleeding and further inflammation.
Anterolateral shin splints: To allow this type of shin splint to heal, the runner must stop running temporarily and do other kinds of exercise. Exercises to stretch the calf muscles are helpful. Once the shin muscles start to heal, exercises to strengthen them, such as the bucket-handle exercise, can be done in 3 sets of 10 every other day.
Posteromedial shin splints: The primary treatment is to stop running and do other types of exercise until running is no longer painful. Running shoes with a rigid heel counter (the back part of the shoe) and special arch supports can keep the foot from rolling onto the outside excessively. Avoiding running on banked surfaces can help prevent shin splints from recurring. Exercises to strengthen the injured muscles are useful.
Strengthening the shin muscles:
Wrap a towel around the handle of an empty water bucket. Sit on a table or other surface high enough to prevent the feet from touching the floor. Place the bucket handle over the front part of one shoe. Slowly raise the front of the foot by flexing the ankle, then slowly extend the foot by pointing the toe. Repeat 10 times, then rest for a few seconds. Do 2 more sets of 10. To increase resistance, add water to the bucket—but not so much that the exercise is painful.
Stand up. Slowly rise up on the toes, then slowly lower the heels to the floor. Repeat 10 times, then rest for 1 minute. Do 2 more sets of 10. When this exercise becomes easy, do it while holding progressively heavier weights.
Stand up. Slowly roll the ankle out so that the inner part of the sole is raised off the floor. Slowly lower the sole back to the floor. Do 3 sets of 10.