• Why is flexibility important?
• What is the importance of hydration in optimizing athletic performance?
• What are the differences between the pediatric/pre-adolescent athlete and an adult athlete?
• Is the incidence of serious knee injuries among female athletes higher at the high school and college levels than their male counterparts?
• Is the higher incidence of ACL injuries among female basketball players due to an anatomical difference between males and females?
• How do I prevent injury when I play golf?
• What are the effects on training as one begins to age?

Q. Why is flexibility important?
A. The value of flexibility for optimal athletic performance and for the prevention of injury is paramount; both to the weekend warrior or to the pediatric or adolescent athlete.

There are a number of benefits to maintaining one's flexibility. It has been shown that:

• Back problems and poor posture may be due to poor flexibility.
• Muscles or joints that lack adequate flexibility are more susceptible to injury.
• Good flexibility can help prevent injury and enhance athletic performance.

Different sports have different flexibility requirements, depending on the body parts used and the level of stress applied to those parts while participating in the activity.

Stretching is the best way to enhance flexibility. Regular stretching can do the following:

• Reduce muscle tension and make the body feel more relaxed.
• Help coordination by allowing freer, easier movement.
• Increase joint range of motion.
• Prevent injuries such as muscle strain or shin splints.
• Promote circulation.

There are three types of stretching:

1. Passive stretching, the most preferred type, is a slow steady stretch where the muscle is held in a stretched position, then released. This technique is very unlikely to cause injury.
2. Passive stretching with an assist is a technique aimed at overloading the muscle. This technique will stretch the muscle more but care must be taken not to cause injury.
3. Active stretching is the technique of bouncing, jerky motions in which body momentum is used to stretch muscles and joints. Jumping jacks or quick repetitive touch touches are examples of this type of stretching. Injury and muscle soreness are most likely to occur with this technique. An expert recommends against doing this form of stretching activity.

The basic objectives of doing stretching exercises are to increase the individual's range of motion, to reduce the potential for injury and increase range of motion gradually. Each exercise should be taken to the point of muscle tightness and slightly beyond. Do not try to force any motion. With these three points in mind, begin developing your stretching program.

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Q. What is the importance of hydration in optimizing athletic performance?
A. Athletes often participate in conditions of extreme heat and humidity which can rapidly lead to dehydration. Hydration is important in helping maintain fluid balance during exercise to ensure normal body function. The amount of fluid that athletes lose depends upon their fitness levels, how well acclimated they are to the environment, the environment itself, the type of clothing they are required to wear and the exercise intensity.

During light exercise in a moderate environment, an athlete can lose 500 to 1000 ml per hour or 1 to 2 pounds of daily fluid needs. Intense exercise in a hot environment can lead to a loss of 1500 to 3000 ml per hour or 3 to 7.5 pounds of daily fluid needs. During exercise, an athlete should drink 16 ounces of water. Following exercise, 8 to 10 ounces of fluid should be consumed during the 15 minute period following exercise.

During exercise, the goal is to fully replace this fluid loss, keeping in mind that drinking to quench thirst will only replace one-half to two-thirds of the fluid lost. For each pound lost, 16 ounces of fluid should be replaced to maintain proper fluid balance. Consumption of 6 to 8 ounces of water every 10 to 15 minutes during endurance exercise will improve performance. The body is able to replace 90% of fluids within the first hour following competition. This process is 46% slower two hours after competition.

There are numerous signs of dehydration. They include dark urine, irritability, light-headedness, unusual fatigue, nausea and headache. Dehydration can result in such things as poor performance, increased risk of heat illness, slow recovery, and finally, increased risk of infections such as cold and flu.

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Q. What are the differences between the pediatric/pre-adolescent athlete and an adult athlete?
A. When considering the training and conditioning of the pediatric and pre-adolescent athlete, it is important to remember that children are not just small adults. The differences between adults and children are significant and should be understood.

The aerobic capacity of children is less efficient than that of adults as they expend more energy at the same exercise level compared to adults. This is due to the higher metabolic demands placed upon their bodies, decreased stroke volume and increased heart rates. Children produce more metabolic heat and have problems with precipitation of this heat since their sweat capacity is less than adults.

There are implications to training and exercise that must be remembered when dealing with the pediatric athlete: aerobic training does not increase the O2 max but will increase coordination and skill. Anaerobic training does not increase glycogen (stored energy) utilization but improves neuromuscular coordination, skills and improves mechanical efficiency of the body.

In any discussion of strength training in the pre-adolescent and adolescent athlete, it is important to remember that the pre-adolescent athlete will increase strength without increasing bulk. Low impact, moderate weight and high rest need to be used in order to prevent growth plate injuries. Good types of exercise are push-ups, pull-ups and sit-ups. Once the child has reached puberty, it is safe to begin true strength training. During this time it important to implement a good flexibility program. This can help prevent some of the overuse injuries with which many athletes seem to be troubled. It is important to remember these differences when dealing with the adolescent athlete.

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Q. Is the incidence of serious knee injuries among female athletes higher at the high school and college levels than their male counterparts?
A. The incidence of serious knee injuries among female athletes at the high school and college levels is 4 to 6 times higher than that of their male counterparts in a study dated June 22, 1999.

Most of these injuries involve tears of the anterior cruciate ligament (ACL), the central ligament in the knee, that provides strength and stability to the joint. The exact cause or causes of this increased risk of knee injury remains unknown, though new studies presented at the annual meeting of the American Society for Sports Medicine may help to provide information concerning this injury.

Two researchers presented scientific papers that address biomechanical and neuromuscular factors that play important roles in the prevention of knee injuries. In his paper, "Differences in Single Leg Balance on an Unstable Platform Between Female and Male Normal and ACL Deficient and ACL Reconstructed Knees," Timothy Hewett, Ph.D. from the Cincinnati Sports Medicine Research and Education Foundation in Cincinnati, Ohio and his co-researchers Mark V. Paterno, MS, PT and Frank Noyes, MD studied 24 subjects, 12 men and women with normal knees, and 12 men and women with injuries to the anterior cruciate ligaments who were scheduled for surgery to reconstruct the ligament.

They discovered that women without any injuries had much better neuromuscular control and balance than the men without injury. However, injured women had much worse control and balance than the injured men, both before and after surgery. Not until a full year post-operatively, did women regain their superior control and balance.

One of the most frequent causes of non-contact ACL injury in women is when landing from a jump. Knee angle is an important determinate of the force of impact on the leg when landing. A study looked at 24 subjects, 12 men and women when the jumped down from a height of 20, 40 and 60 cm. Using reflective markers and 2D motion, the researchers determined that the women landed with a much straighter knee than the men, therefore putting much more load on their knees than men, relative to body weight. It has been shown that increased force upon impact when landing increases the risk of injury to the ACL. Researchers speculate than landing with a straighter knee strains the ACL unnecessarily and may be a contributing factor in ACL injuries among women.

According to a study conducted by Michael J. Belanger, MD from the Brown School of Medicine/Rhode Island Hospital in Providence, Rhode Island and his co-researchers, Robert D. McGovern, BS, Douglas C. Moore, MS, Paul D. Fadale, MD, Michael J. Hulstyn, MD, Joseph C. Crisco, Ph.D. and Michael J. Erlich, MD, estrogen receptors have been identified in ACL, and ACL fibroblasts have been shown to respond to estrogen by decreasing both collagen synthesis and cellular proliferation. In women, knee laxity and looseness have also been shown to increase during pregnancy and during mild exercise. The researchers followed 30 college-aged women between 18 and 33 for 10 weeks through two menstrual cycles. None had a previous ACL injury or previous surgery. Laxity testing was done twice a week, before and after riding an exercise bicycle for twenty minutes. There was no simple cyclic relationship between pre-exercise laxity and day of menstrual cycle, although there was a slight trend toward laxity in the middle of the menstrual cycle.

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Q. Is the higher incidence of ACL injuries among female basketball players due to an anatomical difference between males and females?
A. A prospective study was performed to determine whether there was a difference in the size of the ACL or whether any differences in strength relative to body weight may predispose women to ACL tears.

In a study of one hundred basketball players, 50 males and 50 females were measured and compared against each other for body fat analysis and strength evaluation, and underwent MRI measurements of ACL structure. The most common finding was that the females had significantly smaller ACL's than the males. It was also found that the females had lower strength levels. The researchers believe that a smaller ACL may be an intrinsic risk factor for females. Data also confirms that female athletes are at increased risk of ACL injury and there is also an increased incidence depending upon the sport.

This information was obtained from the American Orthopedic Society for Sports Medicine.

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Q. How do I prevent injury when I play golf?
A. Preventing injury with golfing encompasses three areas: Developing proper swing mechanics, improving overall fitness level, and appropriate warm-up prior to play.

The PGA professional is the best source for improving your swing. A series of lessons and diligent practice will not only improve swing and lessen the stress on the back, but will also improve course performance. Proper body mechanics for course activities such as teeing, marking the golf ball, and picking up the ball out of the hole are important to avoid injury. Each golfer must assess his or her physical capabilities, including strength and flexibility.

In addition to striving to improve these areas, the golfer must also play within his/her limitations. Aerobic conditioning is also important as it delays the onset of muscle fatigue. Walking should be encouraged whenever possible.

Finally, the golfer must make time for appropriate warm-up before playing. While 45 minutes would be optimal, a 10 minute warm-up program is the minimum. This 10 minute warm-up program consists of these four activities:

1. Stretching for two minutes. Before swinging a club, stretching will increase flexibility and blood flow to muscles, preventing strain. Five stretches should be performed for 20 seconds each.

   • Neck rotations. Slowly roll the neck around clockwise and counter-clockwise.
   • Shoulder stretch. Hold the golf club with both hands and raise it over the head. Place the club behind the head, extend the shoulders and hold. Then grasp each elbow and stretch the posterior capsule of the shoulder by pulling the elbow across the body.
   • Trunk side bends. With hands on hips, bend side to side.
   • Trunk rotations. Assume the address position with arms crossed across the chest, hands resting on the opposite shoulders. Rotate the shoulders and hold in each direction. Be sure not to rotate the hips.
   • Toe touches. Standing erect, bend forward from the waist and touch the toes. Hold and rise slowly. For those with a back condition, this should be performed sitting on a bench, leaning forward.
   
   
   

2. Driving range practice for three minutes. Hit shots with a pitching wedge, five iron and driver, spending a minute with each club. Concentrate on tempo and use a half swing only with the wedge, three-quarter swing with the five iron and a full swing with the driver. Focus on proper positioning and swing mechanics while avoiding over rotation of the shoulder.

3. Putting. Spend two minutes putting back and forth across the green, getting the feel of the green.

4. Wait to tee off for one minute. Spend thirty seconds making practice swings with the club that you plan to use on the first tee. Concentrate on tempo, a low take away, balance, a full turn of the back swing, clear of the hips and full finish. Swing slowly, concentrating on rhythm and balance. Spend the next thirty seconds relaxing and visualizing the drive.

See our frequently asked questions on golf injuries.

This information was obtained from the American Orthopedic Society for Sports Medicine.

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Q. What are the effects on training as one begins to age?
A. The typical adult loses muscle mass with age. The loss varies according to the sex of the individual and the level of muscle activity. Other physiologic lapses occur as we begin to age.

The endurance capacity of humans declines about 10% per decade. Recent studies show that aerobic energy production is about 25% lower in the elderly. However, these losses can be minimized or even reversed with training. On following accepted training prescriptions, maximal oxygen consumption or the ability of the muscles to work can increase by 20 to 30% in adults 60 to 80 years of age. Endurance training will improve the ability of the muscles to meet the metabolic demands placed upon them.

For resistance training to be effective, the program cannot be short term. Studies of 12 and 24 week periods at lower intensity tend to show improvement in muscle mass, but no increase in strength. However, if the training program is longer and of sufficient intensity and duration, the elderly may also demonstrate adaptations typically seen in younger participants. After 8 weeks, the absolute amount of weight improved by nearly 175% and the cross sectional area of the thigh muscle increased by 15%. If done with sufficient intensity, even the frail elderly responded to resistance training program much like their younger counterparts.

Much of the decline in skeletal muscle function with aging seems to be related to the progressive production and the demands on muscle and thus does not appear to be inevitable. Each skeletal muscle produces less force and there is a general slowing of the mechanical characteristics of muscle. Aging leads to an increase in the amount of body fat and a decrease in lean body mass.

In summary, the effects of aging on the skeletal muscles can be minimized or reversed with the appropriate conditioning and strengthening program.

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