![[Figure 1]](difiori1.gif)
THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 11 - NOVEMBER 98
Whether for efficiency or bonding, exercising parents often take along their young children in jogging strollers, bike seats or trailers, or backpacks. Some experts view this as dangerous. But those who do it claim it can be safe and rewarding.
So before taking a baby or toddler in tow, consider all the factors, especially risk. As a rule, the younger the child, the greater the risk--a crash could be disastrous for a newborn. But how likely is such an occurrence? It's difficult to speculate because data are scarce, but many factors could increase the risk.
Running or cycling fast leaves little reaction time. Reaction time is even less with a stroller, which will hit an obstacle first. Also, an exerciser may be concentrating on jogging or cycling, lost in thought, or tired, any of which can impair judgment.
Terrain is another factor. Potholes, cracks, or rocks could upset a rapidly moving stroller or bicycle, especially one going downhill.
On the other hand, parents deserve some credit. Responsible parents are going to take every precaution, like exercising in a park instead of in heavy traffic. If you decide to use a child carrier, follow the commonsense safety tips below.
Choosing. If you decide to buy a jogging stroller, don't trade safety for savings: Expect to pay over $200. Look for sturdiness and stability; the stroller should not tip on turns.
Look for a deep seat and a secure seat belt. Alternatively, the stroller should accommodate a well-made car seat. If the carrier needs to be transported in a car, make sure it collapses and reassembles easily. Two-child models are available.
The child must fit the seat, so take him or her to the store. Buy a stroller to fit your growing child. The stroller should have a locking brake and a secure handle that will not turn slippery from sweat. A safety wrist strap will prevent the stroller from getting away from you.
Using. Take a practice jog or two without the child to get used to the stroller. Scope the terrain for what the child will encounter. Never jog at night, even if the lighting seems fine. Using a familiar route may be boring, but it's the safest approach.
Keep in mind that a clear path ahead is not necessarily without hazard. Anticipate hazards like a car door opening or approaching cyclists. Avoid traffic and close quarters of any kind. Never leave the stroller unattended, even for a moment, because it can easily get away from you.
A smooth running surface is a must to keep a baby's head from bouncing, which is important until the child is at least 1. A child's bicycle helmet offers added protection. Large, slightly deflated tires can decrease jostling. Run slower than usual to avoid exhaustion.
Check the weather. Good jogging conditions may not be suitable for a young passenger. Heat and humidity are particularly brutal, especially if the child is clothed to keep the sun off. Sunblock and an overhead canopy help keep the sun's rays off.
Cold and wind can also be a problem. While a lightly dressed jogger will produce adequate body heat, a sitting child won't. So don't judge the child's comfort by how you feel. A windshield or plastic bubble offers added protection (but a bubble can get warm on sunny days--and remember sunscreen).
Choosing. Bicycling with a young passenger may be more dangerous than jogging with a stroller. Some experts totally reject the idea of child bicycle seats. Bicycles are, by nature, unstable, and adding a seat decreases stability even more. The added weight can shift unpredictably, especially if the child weighs more than 40 pounds. Others say cycling can be safe with adequate precautions.
Experts, though, agree that:
Bike seats come in front-mounted and rear-mounted versions. The rear-mounted seat is more popular, possibly because it feels more natural to bikers and because parents feel more protective with their child behind them. But the jury is out on which version is safer.
With a rear-mounted seat, the child's head gets whipped from side to side if the parent needs to pedal hard up hills (especially while standing). Also, a rear carrier tends to make a bike rear- and top-heavy, which can cause it to tip when the biker comes to a full stop, mounts, dismounts, or pushes the bike.
However, most cyclists are used to having extra weight in the rear when they use saddle packs, and this familiarity could make the ride more stable. Also, rear-mounted seats can be larger than front-mounted seats, with high backs to offer greater support.
Critics of the front-mounted seat contend that while communicating with a youngster seated in front may have advantages, the rider may focus too much attention on the child and neglect the road. Also, steering might be more cumbersome, and the child is directly in the path of a head-on collision. As a benefit, older children can see the road ahead and anticipate when to shift weight.
An alternative to the mounted seat is the bike trailer. A trailer eliminates the top-heaviness problem. Also, if the bike crashes or falls, the child might not be affected.
But bike trailers have drawbacks of their own, like reduced communication. Also, the ride can be quite rough. There is extra length to contend with, which can hinder maneuverability. Another factor is that trailers cost much more than seats.
Using. Regardless of the choice of seat or trailer, many common safety tips apply. In addition to avoiding traffic, nighttime workouts, an unattended child, a poorly fitting seat, and inadequate clothing, several other tips apply:
Backpacks may be the safest option, but they are not risk-free.
Choosing. Comfort for the parent is important, especially on long walks. Padded shoulder straps and a waist belt help take much of the load off the lower back.
Backpacks come in various sizes. Large backpacks are more comfortable for the child and offer greater support. But because of their size, they can be cumbersome to use indoors and to store. The backpack must comfortably keep a baby's back, trunk, and head upright.
Safety straps will constrain the child if you fall and keep babies from crawling out. Ample padding on the frame ensures the child's comfort and prevents injury in a fall.
Using. Many of the safety tips cited earlier also apply to backpacks. In addition, remember that carrying a backpack can affect balance. So take smaller steps, avoid rough, hard-to-see, or slick terrain, and don't walk too fast, especially when going downhill. If more than one person uses the backpack, adjust the straps for comfort and stability.
Never wear a baby backpack when fly-fishing, lawn mowing, skiing, or doing other activities in which a fall or moving equipment could harm the child.
Regardless of the carrier, risk can be involved. To have fun with your young one--and avoid leaving the wrong kind of lasting impression--stay alert for the unexpected.
Remember: This information is not intended as a substitute for medical treatment. Before starting an exercise program, consult a physician.
Dr Stamford is director of the Health Promotion and Wellness Center and professor of exercise physiology in the School of Education at the University of Louisville, Kentucky. He is also an editorial board member of The Physician and Sportsmedicine.
John P. DiFiori, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 27 - NO. 1 - JANUARY 1999
In Brief: With the growth of youth sports programs, overuse injuries in young people have become common. Making the diagnosis can be challenging, but often the real hurdles are in identifying the causes of injury. Growth-related factors require special considerations in injury management. A directed history assessing these and other causative factors and a systematic exam help formulate a comprehensive rehabilitation program. Recommendations for a successful return to activity and prevention of reinjury include avoiding heavy training loads and early sport-specific training, taking adequate rest periods, and ensuring proper supervision.
The benefits of regular exercise are not limited to adults. Youth athletic programs provide opportunities to improve self-esteem, acquire leadership skills and self-discipline, and develop general fitness and motor skills. Peer socialization is another important, though sometimes overlooked, benefit. Participation, however, is not without injury risk. While acute trauma and rare catastrophic injuries draw much attention, overuse injuries are increasingly common.
Diagnostic and treatment efforts should focus on how the injury developed and consider issues that are unique to growing athletes. An understanding of these concepts provides the basis for making specific injury-prevention recommendations.
The true magnitude of youth sport participation in the United States is difficult to measure. Approximately 35 million children and young adults between ages 6 and 21 participate in sports, including 6 to 8 million in school programs (1,2). Over the last three decades participation among young women has increased dramatically (2). Involvement in nonscholastic clubs, in sports such as volleyball, basketball, softball, and gymnastics, also appears to be increasing. Furthermore, parents are hiring "personal" coaches and trainers to furnish specialized training beyond that provided by schools or clubs (3). Between school and club programs, private instruction, and popular summer sports camps, many youngsters are training and competing year-round. Though it is uncertain if more children and young adults are involved in sports, it seems clear that those who participate are doing so in a more extensive way.
Because training has become more sport-specific and nearly continuous, overuse injuries are now common among young athletes (table 1: not shown). Recent data indicate that 30% to 50% of all pediatric sports injuries are due to overuse (4-6). In a study (4) of children (aged 5 to 17) who presented to a sports injury clinic, 49.5% of 394 sports injuries were classified as overuse, with boys and girls displaying a similar frequency. The relative percentage of overuse injuries varies by sport, however. In a 2-year study (5) of 453 young elite athletes, 60% of swimmers' injuries were due to overuse, compared to 15% of soccer players' injuries. Athletes who had overuse injuries lost 54% more time from training and competition than those who had acute injuries.
Overuse injuries occur when a tissue is injured due to repetitive submaximal loading. The process starts when repetitive activity fatigues a specific structure such as tendon or bone. With sufficient recovery, the tissue adapts to the demand and is able to undergo further loading without injury. Without adequate recovery, microtrauma develops and stimulates the body's inflammatory response, causing the release of vasoactive substances, inflammatory cells, and enzymes that damage local tissue (7). Cumulative microtrauma from further repetitive activity ultimately causes clinical injury. In chronic or recurrent cases, continued loading produces degenerative changes leading to weakness, loss of flexibility, and chronic pain (8). Thus, in overuse injuries the problem is often not acute tissue inflammation, but chronic degeneration (ie, tendinosis instead of tendinitis).
An understanding of the risk factors contributing to overuse injuries is the cornerstone of prevention. These risk factors have typically been classified as intrinsic or extrinsic. In children, issues specific to the immature musculoskeletal system deserve special consideration (table 2). (See "Case Report: Knee Pain in a New Runner," below.)
| Table 2. Factors Contributing to Overuse Injury Intrinsic Factors Extrinsic Factors |
Growth-related factors. Two factors related to growth are particularly important. First is the susceptibility of growth cartilage to repetitive stress. In children, growth cartilage is present at the articular surface, physes, and apophyses (9).
The articular cartilage appears most vulnerable to injury at the ankle, knee, and elbow. The development of osteochondritis dissecans at these sites is poorly understood and is possibly related to repetitive microtrauma (10).
Apophyseal injuries, including tibial tubercle apophysitis (Osgood-Schlatter disease) and calcaneal apophysitis (Sever's disease), are commonly attributed to overuse (11). They result from traction-induced microtrauma at the tendon-bone attachment. Contributing factors include the weakness of the growth cartilage relative to the tendon, and poor flexibility and increased traction during the adolescent growth spurt.
Physeal injuries may also be caused by repetitive loading. Growth plate injuries have been reported in the proximal humerus in throwers (12) and a badminton player (13) and in the proximal tibia of a runner (14). In gymnastics, repetitive loading of the wrists can injure the distal radial growth plate (15). It appears that metaphyseal ischemia inhibits mineralization within the zone of provisional calcification, prolonging chondrocyte life. This, together with continued division of chondrocytes in the proliferative zone, results in widening of the growth plate (16). Physeal injuries may produce partial or complete growth arrest (17).
The second growth-related factor that contributes to injuries is the rapid change in the relative lengths of the long bones and their adjacent muscle-tendon attachments. Joint tightness can develop when bones lengthen faster than muscle-tendon units, producing inflexibility and dynamic muscle imbalances. The discrepancy may also increase traction on the apophyses and stress at the joint surface (eg, patellofemoral joint).
Other intrinsic risk factors. Patients who have overuse injuries often have a history of previous injury, which may signal repeated errors in training or technique, an inadequately rehabilitated injury, or an unaddressed cause of the original injury. Menstrual dysfunction, often associated with a decrease in bone mineral density, appears to increase the risk of stress fractures in some athletes (18,19).
Alignment abnormalities have been associated with overuse injuries; these include pes planus, pes cavus, hyperpronation, tibial torsion, patellofemoral malalignment, femoral anteversion, and leg-length discrepancy. Although difficult to quantify, excessive ligamentous laxity also may predispose patients to overuse injury. Examples include anterior knee pain in a runner with a hypermobile patella or shoulder pain in a swimmer with glenohumeral instability. Laxity measurements are relatively static and may not accurately represent the dynamic situation (eg, velocity of pronation in a runner). The contributions of alignment problems and joint laxity to overuse injuries remain unclear because prospective studies are few (20). These limitations should be kept in mind when addressing anatomic alignment and joint laxity in individual rehabilitation programs.
The child's level of conditioning is another important consideration. Youngsters will likely benefit from developing general strength and endurance before participating in a training program. Unfit children may lack the proprioceptive skills, and weak and/or inflexible musculoskeletal structures may be unable to withstand the forces of training. Proper preparation and age-appropriate activities may help reduce injury.
Psychological factors should also be considered. Pressures from peers and adults often play a role (see below), but it is important to recognize that the child's level of maturity and self-esteem will influence motivation and the ability to focus on conditioning and safety.
Extrinsic risk factors. Changes in the components of the training program are frequently associated with overuse injury. Though variations in the frequency, intensity, and duration of training are necessary to improve performance, another important training element is often overlooked: rest. Gradual training progression accompanied by scheduled recovery periods is often well tolerated by young athletes. Abrupt increases in any facet of training and/or inadequate rest intervals often lead to overuse injury. An example is a young tennis player who enters a summer camp to work on his serve. Accustomed to practicing 2 hours per day, 5 days per week with the high school team, the athlete now spends 4 to 6 hours each day emphasizing the serve and quickly develops a rotator cuff tendinopathy. Parents and coaches should be aware that training programs designed for adults are not appropriate for young athletes. In fact, because of the great variation in physical and emotional maturity among children and adolescents, individualization of training schedules is encouraged.
Faulty equipment is another risk factor. Footwear should be well-fitted and suited to the demands of the activity. Running shoes should be replaced at regular intervals because they can lose more than 40% of their shock-absorbing capacity after 250 to 500 miles (21). Other examples include the grip size and string tension of a tennis racquet and the fit of a bicycle. Equipment changes may also result in injury. A well-conditioned track athlete who switches from training flats to spikes for interval workouts may develop lower-extremity problems from changes in running mechanics.
Poor technique can also produce injury. In tennis, for example, flexing the wrist at ball impact during the backhand stroke commonly causes lateral epicondylitis. Instruction in proper technique helps treat and prevent overuse injury. Finally, changes in training surfaces may lead to injury. Rapidly introducing hill running, running on a beach or other tilted surface, and running on uneven or hard surfaces can trigger injury.
Pressure from others--especially adults--may play a role in the development of overuse injury. Parents and coaches who promote excessive intensity or who encourage a "no pain, no gain" or win-at-all-costs attitude may well contribute to injury. Assessing a child's motivation can be helpful: Is he or she genuinely interested in playing, or doing so only because of others' expectations? Children who have uncharacteristic symptoms or fail to progress as expected with treatment may be expressing their lack of interest in the sport.
History. A thorough history cannot be overemphasized. A detective-like approach will not only help establish the diagnosis, but will also suggest the severity of the injury and reveal many potential predisposing factors. Have patients describe when they first recognized the injury. Once this is determined, ask detailed questions about training in the several weeks before the first signs of injury:
In adolescent girls, document age of menarche and whether cycles are regular or irregular. Menstrual dysfunction should be evaluated concurrently.
Recording a patient's age and reviewing the growth curve can determine if he or she is in a rapid growth period. The mean onset of the adolescent growth spurt is approximately 10 years for girls and 12 years for boys. Peak height velocity is reached, on average, at age 12 for girls and age 14 for boys. Injuries that occur without obvious training changes or contributing factors may simply be related to the musculoskeletal changes associated with accelerated growth.
Next, have the patient describe the location and quality of the pain and when it occurs during activity. Pain that occurs at the end of an activity and resolves before the next training session signals a relatively mild injury; pain during activity that impairs performance is more severe. One must always consider the possibility of occult tumors or rheumatologic conditions in young athletes who have chronic pain symptoms.
Observe patient-parent interaction in the exam room:
Identify how the athlete, parents, or coaches have attempted to treat the injury. Those who have been to several physicians may have unrealistic expectations that should be addressed.
Physical examination. The examiner should localize the complaint, identify injured tissue, and assess all structures that dissipate force in the involved extremity. For a patient who has anterior knee pain, for example, the exam should proceed from the ground up, beginning with foot and ankle alignment and continuing proximally. This method can identify underlying malalignment, inflexibility, muscle imbalance, joint laxity, or restriction of motion. The examiner also should compare flexor-extensor muscle groups and the injured extremity to the uninjured.
Careful palpation of the painful area will often reveal the exact injury site. Recreating the loading pattern can help reproduce symptoms. Simple methods include having the patient run or hop in place or applying pressure over a musculotendinous structure while applying resistance at various joint angles. When provocative maneuvers are unsuccessful, examining the child immediately after the sports activity may be useful.
Occasionally, symptoms are difficult to localize. Poorly localized symptoms are not unusual for some overuse injuries, such as back pain in a dancer who has a stress reaction of the pars interarticularis. In other situations, the sport may be unmasking an underlying problem. Vague knee pain, for example, may be the presenting complaint of a patient who has osteochondritis dissecans, a hip disorder, or an osteosarcoma.
Imaging studies may be helpful in some situations. Radiographs can identify osteochondral lesions (figure 1), stress fractures, tumors, and growth-plate widening. Additional studies, such as bone scans or magnetic resonance imaging, may be useful if plain radiographs are unrevealing (figure 2). The specifics of each case guide the decision to obtain radiologic studies, and which to choose.
The fundamental goal of treatment is to develop strong, flexible tissue that absorbs the forces of the sport. The principal measures:
![[Figure 2]](difiori2.gif)
Relative rest. The initial phase of treatment involves protecting the injured site from a level of impact loading that perpetuates overuse by reducing training volume and using alternative activities to maintain aerobic conditioning and morale. The patient's clinical history provides a guide to the amount of rest needed from sport-specific training (table 3: not shown). Less severe injuries such as mild patellofemoral pain warrant a 25% to 75% decrease in training load; a more severe injury, such as a stress fracture, initially requires complete rest from the offending activity. Examples of alternate activities include pool running with or without a flotation vest, bicycling, rowing, and swimming. Patients may continue sports activities that do not stress the injured area.
Ice. Ice, an effective modality that should be used throughout treatment, reduces swelling and pain by causing vasoconstriction, slowing nerve conduction, and reducing cellular metabolism (22). It should be applied lightly over a cloth or bandage for 10 to 20 minutes several times a day for the first 48 to 72 hours and after rehabilitation exercises. Ice massage, rubbing the ice in a circular motion over the injury, is another option.
Other modalities. Topical heat (ie, moist heat packs) may help increase collagen extensibility and reduce stiffness. Other modalities such as ultrasound, iontophoresis, and electrical stimulation may be useful adjuncts. The clinical benefits of nonsteroidal anti-inflammatory drugs (NSAIDs) have not been clearly demonstrated (23). When rest and ice have not relieved patients' pain, a short NSAID course may reduce pain and allow rehabilitation to proceed.
Rehabilitation. Once pain has been controlled, supervised rehabilitation can begin. The objectives of rehabilitation are to restore range of motion, strength, flexibility, and proprioception. Returning to the sport before reaching these endpoints increases the risk of reinjury.
As range of motion is restored, pain-free resistance exercises are begun. Isometrics and limited isotonics are often part of this stage; these activities should be supervised to guard against improper technique and equipment misuse. Soft-tissue techniques can be used to reduce adhesions and loosen tight structures.
Gentle flexibility exercises are added when strength and range of motion improve. Overstretching should be avoided. Strengthening and flexibility exercises should also address adjacent uninjured structures. Aerobic conditioning is also initiated to prepare patients for their return to sport. The level of pain during activity and symptoms and findings the following day guide the progression. Significant improvement signals the time to add eccentric and isokinetic exercises, which require close supervision to ensure correct technique. Simultaneous increases in exercise resistance and velocity should be avoided.
After range of motion, strength, and flexibility improve, gradually adding sport-specific activities allows patients to regain proprioception and reacquaint themselves with the biomechanics of the sport. Patients can resume training and competition when they have recovered their muscular and aerobic endurance and can perform sport-specific activities without pain.
Athletes who complete a thorough rehabilitation may suffer reinjury if the risk factors that led to the problem are not addressed. Athletes, parents, and coaches should be educated about training errors that may have occurred, the importance of scheduled rest periods, and the need to avoid excessive training volumes, especially during the adolescent growth spurt. To correct poor technique, the coach or trainer often must instruct athletes and provide reminders about possible relapses.
Patients may benefit from advice on appropriate footwear and equipment. Over-the-counter shoe inserts can help modify biomechanical malalignment. In some situations, such as marked pes planus in a patient who has refractory plantar fasciitis, custom orthoses may be needed.
The American College of Sports Medicine estimates that 50% of overuse injuries in children and adolescents are preventable (24). Preparticipation screening, required by most schools, should be encouraged for all children involved in organized athletics. This is an excellent opportunity to identify sport-specific injury risk factors and to assess young people's maturity, skill level, and motivation for the sport. Parents should ensure that their children will receive proper supervision and coaching. They can lobby local organizations to sponsor coaches' attendance at coaching and safety seminars.
Training programs should accentuate general fitness and avoid excessive volume. All programs for youngsters should include conditioning and flexibility. Early sport specialization should be eschewed. Adults may seize on an example of a child who began exclusive training for a sport and became a local or national success, but the daily repetition required to perfect sport-specific skills too often leads to injuries. Experimentation with different sports allows children to develop fitness and motor skills, enjoy the social aspects of sport, and choose the sports they prefer. Parents can be reassured that there are many examples of outstanding athletes who did not become involved in their sports until a relatively late age. Bill Rodgers, four-time winner of the Boston and New York marathons, started running cross-country at age 15. After Phoebe Mills won a bronze medal in gymnastics in the 1988 Olympics, she took up diving and competed in national competitions from 1990 to 1994. Michael Jordan didn't make his high school's varsity team until he was in 11th grade.
Because children rarely suffer overuse injuries when they control the intensity level, coaches and other adults should avoid setting rigid expectations about training intensity. Despite scarce data about training progression and injury, gradual progression should be stressed. A general guide is the "10% rule": Total training (intensity, frequency, duration, or any combination of these) should increase no more than 10% at a time (6,24). Thus, a young runner who runs 20 miles per week would run 22 miles the next week, without changing pace. The rule is a useful starting point, but must be adjusted for each athlete.
Periodization may also help to reduce overuse injuries and prevent overtraining. This technique involves the systematic cycling of training loads over set periods of time with well-defined rest periods. Finally, training should be carefully monitored during the adolescent growth spurt. Because growth-related factors can predispose patients to injury, it may be appropriate to temporarily modify training during this period.
A diligent search for contributing factors and an understanding of the issues that are unique to children are essential to injury management. Incorporating these elements into a comprehensive rehabilitation program usually results in a successful return to participation. Attention to preventive measures such as training progression and appropriate supervision will allow youngsters to continue to enjoy the many benefits of organized play.
A 13-year-old girl presented with a 2-week history of left anterior knee pain. She was a swimmer, but she had begun training with the school's track program 3 weeks earlier, and running was a new sport for her. She had been running 8 to 10 miles per week (up to 2 miles per session) and said pain onset was gradual. At presentation, she reported pain with initiation of running such that she could no longer complete 1 mile. The patient said her pain was more noticeable when she walked up and down stairs and that her knee felt a bit stiff when she was sitting in class.
History. The patient did not recall any prior knee injury, and there was no history of locking, catching, swelling, or instability. She reported no other sports-related injuries and had not been strength training. The majority of the running was done on either the road or a dirt track. She had iced the knee the first few days she had pain, but had not done so recently. Instead, she purchased a neoprene knee sleeve, which did not provide much relief. She denied any pain when sleeping at night, and had no other joint complaints. Her medical and surgical histories were otherwise unremarkable. She had not yet begun menses.
The patient was accompanied by her mother. The interaction between mother and child appeared appropriate. The patient provided most information without prompting or much qualification from her mother. She stated that her participation in track stemmed from her own interest.
Physical examination. Height and weight were in the 35th and 20th percentiles for her age respectively. Her growth history was not available for review. Examination of the lower extremities revealed normal-appearing arch heights and mild genu valgum. Tubercle sulcus angles (seated Q angles) were slightly increased bilaterally. No pelvic obliquity was observed. No knee effusion was noted, and the patient demonstrated full pain-free range of motion without crepitus. Patellar inhibition testing was positive on the left, but negative on the right. Patellar tilting and medial glide were normal. The medial and lateral facets were nontender, and a nontender medial plica was noted. Hamstring flexibility was decreased bilaterally. Quadriceps tone was poor. The ligaments were stable. The patient's running shoes were moderately worn cross-trainers.
Diagnosis. A working diagnosis of patellofemoral pain syndrome was established.
Treatment. The patient's running was reduced to one quarter mile every other day, preferably on grass. Ice massage was recommended three to four times daily, and swimming was selected as an alternative activity for conditioning. She was instructed to begin daily isometric (open- and closed-chain) exercises for the quadriceps, hamstrings, and gastroc-soleus complex with an emphasis on the vastus medialis obliquus. A lower-extremity flexibility program was also started, focusing on the hamstrings. Proper running shoes were recommended. If symptoms were improving, she was allowed to run 1 1/2 miles total the second week and 2 miles the third week.
By the time of her follow-up visit 3 weeks later, the pain had resolved, and she was running 1/2 mile four times per week. Isotonic strengthening was begun to build lower-extremity strength. Running mileage was slowly increased.
At her final visit, 6 weeks after follow-up, she had been running with her team without limitation for 1 week. The patellar inhibition test was negative and knee flexibility and muscle tone had improved. She was advised to maintain strength and flexibility exercises and avoid rapid training changes.
Discussion. The patient's pain was clearly related to the onset of her running program along with several other contributors. Intrinsic factors were growth, poor hamstring flexibility, inadequate conditioning, and anatomic malalignment (mild genu valgum and increased tubercle-sulcus angles). Extrinsic factors were rapid training progression, inappropriate footwear, and hard running surface (road).
Dr DiFiori is an assistant professor in the Department of Family Medicine Division of Sports Medicine and assistant team physician in the Department of Intercollegiate Athletics at the University of California, Los Angeles. Address correspondence to John P. DiFiori, MD, UCLA Department of Family Medicine, 200 UCLA Medical Plaza Building, Suite 220, Los Angeles, CA 90095; e-mail to jdifiori@ucla.edu.
Theodore Ganley, MD, with Carl Sherman
Exercise Is Medicine series editor: Nicholas A. DiNubile, MD.
THE PHYSICIAN AND SPORTSMEDICINE - VOL 28 - NO. 2 - FEBRUARY 2000
Exercise is good for everybody. For kids, it pays double: increasing vitality today while building the foundation for a healthy tomorrow. Active youngsters are stronger, leaner, and more fit. They have extra energy and feel better about themselves. They get a head start on lifestyle habits that will protect against heart disease, diabetes, and osteoporosis.
There's no better investment in your child's present and future health than promoting safe, regular exercise.
Q. What exercise is best?
A. Children and adolescents, like adults, should participate in vigorous physical activity on a regular basis--at least a half hour, three or four times a week.
The best kind of exercise is one your child will do regularly. Help him or her find activities that are fun and rewarding. Baseball, walking, soccer, jumping rope--anything's OK if it's enjoyable and done safely.
Preaching or pushing kids into activities they don't like is likely to backfire. Youngsters who learn that exercise is a chore all too often become inactive adults.
Remember, too, that exercise needn't be organized. Encourage your child to take the active option in daily life: Walk instead of ride, take the stairs, not the elevator, develop an interest in hands-on activities like building a snowman. Short bursts of activity add up.
Q. What about safety?
A. Minor mishaps such as bruises and sprains are a fact of life for on-the-go youngsters, but simple precautions will minimize the risk of serious injury.
Q. Is it good to get the whole family involved?
A. Kids learn by example: When a father gets involved with his child's activity, the child is three times more active than children with inactive parents. Why not foster fitness together? Make long walks, cycling, and active vacations a family tradition.
Remember: This information is not intended as a substitute for medical treatment. Before starting an exercise program, consult a physician.
Dr Ganley is orthopedic director of sports medicine at the Children's Hospital of Philadelphia. Mr Sherman is a freelance writer in New York City.
THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 6 - JUNE 98
About one of five American kids is overweight enough to be considered obese. (Obesity--being 20% or more overweight--is considered a disease because it is associated with so many health problems, like heart disease and diabetes.)
And childhood obesity tends to mature into adulthood obesity. About a third of adults are obese, and a third of these got that way in childhood. That's why it's crucial to keep kids from becoming overweight--and to help obese kids lose weight.
Childhood obesity and an inactive lifestyle go hand in hand. More than half of children are inactive, and physical activity drops sharply during adolescence. Much of this drop stems from surroundings that promote inactivity. In high school, for instance, enrollment in required physical education classes dropped from 42% in 1991 to 25% in 1995.
Generally, kids who are physically inactive at home are inactive elsewhere. They also tend to take the least active role in organized activities. Many times, obese children want to participate in an activity but feel embarrassed and awkward.
To help "activate" kids, a great start is to decrease their time spent glued to the TV. Cutting back from more than 21 hours of TV watching a week (a typical American dose) to 7 hours a week could cut a child's risk of obesity by a third (1). In contrast, each added hour of TV increases the risk. If a child adds 5 hours of TV viewing per week, he or she is 10% more likely to become obese.
Kids manage their weight best by making permanent lifestyle changes, like limiting TV to a few shows a week, eating right, and being active with their family. If parents, teachers, and friends provide activity as an alternative to inactivity, kids can try active options and turn them into healthy habits.
When parents have positive attitudes, kids feel supported. A study (2) showed that at least one parent must participate in the weight-loss process for long-term success. Parents, brothers, and sisters serve as role models and reinforce successes.
Another important reason to get the whole family involved is that obese parents tend to have obese kids. If both parents are obese, a child has an 80% chance of being obese, compared with a 50% chance if one parent is obese and a 10% chance if neither parent is obese. Although the causes of obesity involve many factors, environment strongly influences the degree of overweight.
People lose weight when they use more calories than they take in. The best weight-loss program, therefore, involves two things: eating less and getting your body moving more. Of the two, taking in fewer calories from food can yield a bigger calorie difference more readily.
Kids can modify their diet gradually by cutting out high-fat snacks and desserts and eating more fruits and vegetables. Taking smaller portions also helps.
Physical activity is also important. Kids' days should be loaded with activity (table 1). Walking to do errands, bopping to music when drying dishes, and riding a bike to visit friends all burn calories.
Table 1. Options for Adding Physical Activity to Family Life
Identify opportunities for exercise in all areas of life (walk to do errands, take stairs instead of escalators, etc)
Walk the dog
Buy toys and gifts that promote physical activity (balls, active games, sports equipment)
Adopt a highway, trail, or park as a family activity
Remember that household chores are exercise (yard work, washing the car, cleaning house, snow shoveling)
Encourage job-seeking kids to look for active jobs (bicycle messenger, paper carrier, lawn service)
Find fun, physically active ways to celebrate special occasions (like a hike and a picnic for a birthday party)
Add exercise to weekend plans (hike, fly a kite, swim)
Plan one special physical activity event each week for the whole family (walk, hike, bike)
Join activity programs at school (intramural sports, athletic teams)
Encourage friends or extended family to join in
In addition, children need to incorporate 1 hour of more structured light to moderate activity into each day (table 2). It's best, though, to emphasize total calories burned, not the intensity of any one activity. Walking a mile fast or slowly burns the same number of calories--walking slowly just takes longer. Light to moderate activities seem to be most enjoyable for overweight youth and therefore easier to keep up.
Table 2. Various Types of Moderate Activity*
Bicycling at 10 mph
Brisk walking at 4 mph (15 minutes/mile)
Dancing
Gardening
Hiking
Ice skating
In-line skating or roller skating
Jumping rope slowly
Playing doubles tennis
Raking leaves
Shoveling snow
Skateboarding
Washing and waxing the car
Weight training, circuit
* Each activity will burn, on average, about 6 times the calories used at rest (about 300 calories per hour for a 100-pound person).
In contrast, moderate to heavy activities seem especially strenuous to overweight kids. It's better to reduce the intensity (see "How Weight Loss Goals Are MET," below) and increase the time.
Another avenue is strength exercise. Overweight kids can excel when they pump iron, because they are often the strongest kids in their class. An inexpensive dumbbell set can provide a good home workout. Along the same lines, overweight kids can use their strength in sports like baseball or softball, where they might star as batters.
Parents can help create an active environment by supporting physical education in schools and community recreation through more bike paths and routes, night basketball leagues, hiking trails, and playgrounds. In addition, parents can coach or assist with kids' sports.
Both planned exercise and more daily activity can make a big difference. Parents can provide opportunities for overweight kids to choose activity and then support them.
Scientists measure the intensity of a physical activity in metabolic equivalents, or METs. One MET equals the number of calories that your body burns at rest. Light to moderate activity of 4 to 6 METs, therefore, takes 4 to 6 times as much energy as sitting still.
If a 100-pound child would replace 1 hour of daily TV with a 6-MET activity (table 2), he or she would lose 24 pounds in a year (if the child's diet didn't change). Combine that program with a diet lower in calories, and the weight loss is even higher. What's more, the physical activity can be broken into several shorter bouts in a day to accumulate 60 minutes and still give the same benefits.
The number of calories burned for most activities is based on body weight--which is good news for heavier kids. Because of their additional weight, obese children may burn 50% more calories than other kids at identical activities.
Remember: This information is not intended as a substitute for medical treatment. Before starting an exercise program, consult a physician.
Dr Parr is a professor in the Department of Health Promotion and Rehabilitation at Central Michigan University in Mount Pleasant, Michigan. He is a fellow of the American College of Sports Medicine.