One of the most common injuries among triathletes is runner’s knee. This painful, potentially crippling dysfunction can be prevented by implementing proper training, exercise and stretching techniques.

The Causes. This condition involves inflammation and swelling of the patello-femoral joint below the knee cap. The patella (knee cap) acts as a pulley for the quadriceps to give strength and power to the lower leg. It glides along a groove in the knee joint, but can start functioning abnormally due to a variety of factors, such as overuse, muscular imbalances and poor foot positioning.

Then this occurs, the musculature around the knee can stiffen, particularly as a result of activities that involve mid- range movement and do not elongate the muscles of the leg through full- range activities. Such routine activities as walking, climbing stairs, and sitting entail mid-range movements that do not fully extend the knee.

Stiffness in the knee dramatically decreases the leg’s strength and shock- absorbing capabilities during activities such as running, walking and squatting. Leg joints begin to take much of the chock formerly absorbed by the musculature. This can cause a potentially debilitating cartilage breakdown in the knee cap that may require surgery and extensive physical therapy.

A female triathlete is more susceptible to a runner’s knee than her male counterpart: Her pelvis is wider, causing greater angles between the upper and lower leg while running. This tendency causes a twisting force in the leg that can injure the patello- femoral joint.

In its earliest stage, runner’s knee is a general tenderness around and under the knee cap. As it progresses, it can become an occasional throbbing pain most evident during stressful sport activities. In the second stage, the pain can be felt during exercise routines. The third stage is marked by a sharp ache during routine motions such as walking, bending and climbing stairs. In the fourth stage, the pain intensifies during rest periods. The fifth and final stage involves disability and constant anguish throughout the day.

In the first stage of runner’s knee, a sufferer can treat the dysfunction by resting, icing irritated areas of the knee, applying compression and elevating the leg to reduce swelling. Although a triathlete should curtail his/her usual training routine to promote healing, exercises such as walking, short- duration low- intensity cycling and running in pools can be substituted for limited durations to maintain conditioning.

Second- stage dysfunction requires greater attention to stretching and exercise routines to promote flexibility of the leg muscles. However, symptoms of third- through fifth- stage injury should receive professional attention and a closely monitored program of rehabilitation.

Although some competitors wear artificial supports in response to the early stages of knee injury, such devices should only be utilized as part of a supervised program of rehabilitation- otherwise they might mask pain without preventing the progression of damage.

Preventive Measures. Runner’s knee most often results from specific tendencies and habits ranging from training technique to shoe selection. The following steps are the best preventive measures for triathletes:

• Incorporate a regular regimen of leg- flexibility and strengthening exercises into your training program. This usually involves a routine that highlights straight leg raises, leg curls, knee extensions and hip extension exercises to prepare muscles for the stresses of running.
  
  
• Pace yourself when setting a running routine. A good rule of thumb is to increase your running distance by no more than 10 percent a week. Pay attention to total weekly running-base mileage. Every triathlete has an upper limit in which he or she will have trouble. For some people it is 30 miles a week. Others can sagely run 100 miles. Respect your mileage limit and stop before your knee.
  
  
• Adjust your running style to begin each stride with a heel strike and follow with a push off, your knees slightly bent. Running with toe strike or excessively bent knees will eventually cause strain.
  
  
• Select suitable running shoes that properly absorb trauma to the knees and are comfortable from the moment you put them on. Running shoes need to balance cushioning for shock absorption with stability for abnormal movement control. This balance is individualized and shoe selection will vary with body type and running style.
  
  
• Respond to pronation (rolling of the feet) by doing flexibility exercises for calf muscles, selecting proper running shoes and adjusting running style with proper heel strike, push off and knee positioning.
  
  
• Keep track of your running shoes’ condition. Most shoes have life spans of 300-600 miles and should be replaced before they’re worn. If shoes begin to break down, they provide less support and shock absorbency.
  
  
• Avoid running on sidewalks and other concrete surfaces because their hardness increases shock to the knees and leg muscles.

Bicycling raises its own concerns when it comes to preventing runner’s knee. Attention must be paid to proper cadence with a high speed of 90 rpm, proper seat height to avoid excessive bending of the knee and correct gearing sequences that properly limit muscular stress. Knee strain can occur when the seat is positioned too far forward, when the cleats are set too far forward or when crank arms are excessively long. Total mileage, excessive hill climbing and training intensity also are critical factors.

An Ounce of Prevention. Preventive measures can be taken in nearly every endurance sport, most of which involve proper posture, form and equipment. Good coaching can be a key element in ensuring injury prevention and improved performance.

Chronic injuries can limit a triathlete’s performance, can rob him/ her of the pleasure derived from the sport and, in the worst cases, can prevent the triathlete from competing again. Therefore, it is important to respond to leg injuries, like the advanced stages of runner’s knee, by seeking immediate medical attention. A carefully administered rehabilitation program can also speed the recovery process.

There are no guarantees against leg injuries, even for the most cautious and seasoned triathlete. However, proper form, a balanced exercise program and common sense can help prevent many of the most frequent types of discomfort and dysfunction.

Bruce R. Wilk of Miami, Fla., is a board certified physical therapist and director of Orthopedic Rehabilitation Specialists as well as an avid triathlete.