Running is a simple and convenient sport that makes it a popular form of exercise. It lowers the rate and progression of disability, risk to chronic diseases, and mortality rates.
However, runners are also exposed to the risk of injuries. The common injuries sustained are mostly due to overuse that usually heal without major intervention.
More serious injuries can lead to long-term consequences if precautions are not taken and appropriate treatment not started early.
Previous injuries and total running mileage seem to consistently predict running injuries. For example, it is estimated that serious distance runners, defined as those who run more than 25 miles (40km) a week, have an injury rate of about 30 per cent per year.
There are many injuries associated with running, affecting different parts of the lower limb. About 25 per cent affect the knee; 20 per cent, the lower leg; 16 per cent, the ankle; 10 per cent, the upper limb; 7 per cent, hips and pelvis; and 7 per cent, the lower back.
A survey carried out in the US shows a differing pattern of injury between younger and older runners. Knee and shin problems appear to affect the young, while older runners more commonly sustain injury to the calf, Achilles tendon and hamstrings.
For the purpose of this article, meniscus injury that can lead to long-term arthritis of the joints will be discussed.
The knee is the largest joint in the body, and has many parts that perform different functions.
The menisci (medial and lateral meniscus) are thick rubber-like pads of cartilage tissue that act like shock absorbers in the knee joint. A meniscus can be torn, commonly after a forceful twisting injury to the knee.
Meniscal tears are one of the most common injuries that can occur from running. If left untreated, some may progress to osteoarthritis of the knee.
Meniscal tears can occur at any age, although the type of tears may differ. In the younger age group, tears are usually related to sports trauma from twisting injuries, while tears in the older age group tend to be due to age-related changes in the meniscus.
Often, there is a "pop" when the meniscus tears. If the tear is small, the symptoms are often minimal, with little effect on walking or running. There may be associated swelling, and often, full weight-bearing is painful, with reduced range of motion.
When large meniscal tears occur, they may cause catching, locking or sudden "giving way" while walking. This is a result of loose fragments that slip into the joint between the femur and tibia. These may act as loose bodies abrading the articular cartilage at the end of the femur and tibial surfaces.
Persistent abrasion will lead to loss of articular cartilage, and eventually, bone is exposed, leading to osteoarthritis when both bone surfaces of the femur and tibia scrape against each other, causing pain, deformity and reduced function of the knee.
Tenderness along the joint line and special examination on the knee may produce a clicking sound suggestive of a meniscal tear. An X-ray is often not conclusive, but is usually done to exclude bony loose fragments or other bone conditions causing similar symptoms.
MRI is most helpful in confirming the diagnosis, and more importantly, to check for other injuries to the articular cartilage on the femur and tibia that will influence treatment and any additional procedures required.
Often, if the knee is stable and the symptoms are not prolonged, PRICE management is all that is needed. PRICE stands for Pain control, Rest, Ice, Compression and Elevation.
Pain control can be managed by NSAIDs (nonsteroidal anti-inflammatory drugs), or a newer class of medications known as selective cox-2 inhibitors, which markedly reduces gastric and gut irritation and ulceration.
It is a common mistake to think of such drugs as pain control medication only. It is equally important to be aware that these drugs reduce pain by reducing the inflammatory process that occurs after any injury.
The ideal pain control medication should be one that acts fast, with effects that last a longer time.
Next is rest. This is often trivialised, but it is essential to give the injured meniscus adequate time to heal. As is often the case, healing is programmed in humans, but if the injured part is not rested, this will prolong the healing process beyond the average four to six weeks.
Crutches and non-weight bearing, and sometimes bracing the knee, allows it adequate rest for healing.
An elastic compression support would help to reduce the additional swelling and blood loss after injury, and also restricts the range of motion for pain relief.
In addition, ice is a simple and effective means of reducing swelling in an acute injury, but needs to be applied every 20 minutes at a time several times a day. Direct contact of ice to the skin continuously will cause cold burns, leading to more injury, so wrap the ice with cloth or a bag.
Lastly, elevation is often overlooked and is the simplest measure to reduce swelling by elevating the knee above the horizontal level of the heart.
When pain and swelling persists in spite of non-operative treatment, then surgery may be needed. Knee arthroscopy, a form of key-hole surgery, is one of the commonly performed knee procedures. It involves inserting a small video camera through a small incision into the knee joint. Another small incision is often used for inserting specialised small instruments. This provides an excellent view of the injury of the knee for close examination, and manipulation with a probe or treatment with other instruments.
Reparability depends on the size, location and type of tear. Occasionally, it is possible to trim some parts of the meniscus and repair some other parts with the aim of preserving as much of the meniscus as possible.
Trimming the meniscus probably increases the risk of osteoarthritis (with the loss of meniscus that does not grow back). However, the risk of articular cartilage damage from loose symptomatic meniscal fragments can be more damaging, leading to more rapid osteoarthritis changes. It is analogous to a stone inside a shoe abrading the sole of the foot, causing blistering and ulceration.
Other factors that need to be considered in the treatment of meniscal tears include age, activity level and occupation.
Rehabilitation of the knee after arthroscopic surgery is another often-ignored aspect that has a major bearing on the final result.
Early controlled rehabilitation is essential for optimal results. Occasionally, a knee brace is needed after surgery to prevent excessive movement.
During the healing process, controlled progressive range of motion and exercises to maintain muscle strength is necessary. When meniscal healing is complete, a full range of motion and strengthening programme is added.
Much of the rehabilitation programme can be done at home with simple resistive exercises with exercise bands that are cheap and lightweight.
Muscles, tendon and ligaments are important to support the knee. As such, muscle conditioning, as well as muscle, tendon and ligament flexibility, are important to prevent knee injury.
Muscle strength, endurance and balance training of the entire lower limb, and sustained gentle stretching of the hamstring and calf muscles, are important, as tightness of these muscles are common in runners.
Adequate warm-up and stretches before running is essential to prevent muscle, tendon and ligament injuries. It is equally important to cool down after running to enable the body to recover.
Proper running shoes are important to prevent injuries, particularly the foot. There are essentially three types of such footwear. A motion-control shoe is for a runner who needs more rigid support; a support shoe is for those who do not need much control; and a cushion shoe is for a runner with a rigid foot that requires flexibility and cushioning for shock absorption.
Adequate warm-ups is important to allow the body to prepare for the demands of intense running. It increases the blood flow to the muscles. This can be done with running at an easy pace at the beginning. The warming-up duration can vary, with those who are newer to running taking a longer time.
After warming the muscles, stretches need to be done to improve flexibility. Stretching cold muscles can cause injury. Stretches should probably best be done standing up at the start of the running session. Floor stretches should be carried out during the cooling down after running. This will allow the body to respond better and prevent injuries.
Stretches should be done slowly and gently to avoid muscle tension and pain, with each stretch held for 10 to 30 seconds.
The cooling-down phase at the end of running is to allow the body to recover effectively. It should start with a gradual decrease in running intensity at the end of the running session, and slowing down to a walk at a comfortable pace until breathing and heart rate returns to normal.
In summary, running is a healthy way to stay fit. With proper precaution and an adequate regular training programme, the risk of injury can be minimised. It is important to be aware that injuries may occur and that early intervention is advisable to prevent longer term disability.