chapter 6

1. chapter6 Flexibility Training

2. Specificity Because flexibility is specific to each joint, having good hip flexibility is no guarantee that you will be flexible in the shoulders, back, neck, or ankles.

3. Joints • Joint structure determines the limits of our range of motion (ROM). • Hinge joints, such as the knee and elbow, have an ROM of 130 degrees. • Ball-and-socket joints, such as the hip and shoulder, allow the greatest ROM. • Elliposoidal joints, such as in the wrist, are among the least flexible.

4. Factors Affecting Flexibility • Joint structure • Age and gender • Muscle bulk • Connective tissue • Improper weight-training techniques • Improper stretching procedures • Activity level • Excessive body fat

5. Flexibility Definitions • Fibrosis—A condition in which muscle fibers degenerate with age and are replaced by fibrous connective tissue. • Elasticity—The ability of connective tissue to return to its original form. • Muscle extensibility—The ability of muscle tissue to stretch. • Plasticity—The inability of connective tissue to return to its original form.

6. Flexibility and Weight Training • Individuals who perform each weight-training exercise by going through the full ROM (see chapter 7) for both the agonists and antagonist muscles (such as the biceps and triceps when performing barbell curls) do not suffer loss of flexibility, and can actually increase their ROM. • Strengthening muscles through the full ROM can increase flexibility even in elderly adults.

7. Importance of Flexibility A regular stretching routine will • help increase ROM, • improve performance in some activities, • help prevent soft-tissue injuries, • aid muscle relaxation, and • help you cool down at the end of a workout.

8. The Back • The human body has 33 vertebrae that extend from the base of the skull to the tailbone (see figure 6.1). • Shock absorbers known as discs are located between vertebrae. • The vertebrae form a double-S, reverse curve to ensure proper balance and weight bearing. • If the vertebrae were placed directly on top of one another, the back would be only 5% as strong as it is. One step would produce enough trauma and brain jolt to cause concussion.

9. Figure 6.1 The Vertebral Column

10. Lower-Back Pain (LBP) • LBP affects an estimated 8 to 10 million people in the United States, who lose over 200 million workdays each year. • The occurrence of nonspecific LBP in 14- to 16-year-old adolescents has almost reached the level experienced by adults. • Injuries to the lower back are also common among both amateur and professional athletes in sports such as golf.

11. LBP Cause and Cure • The exact cause of most LBP is a mystery. • You can reduce your chances of developing LBP by changing the way you • stand, • bend, • lift objects, • sit, • rest, • sleep, and • exercise.

12. Exercise • Experts now feel that for most people who experience the sudden onset of lower-back pain, the best treatment may be no treatment at all. • Research supports the use of early activity and exercise in the treatment of both acute and chronic LBP.

13. Other Benefits of Stretching 1. Warms deep muscle fibers, joint fluids, lubricants, and synovial fluids to provide more efficient joint movement. 2. Prepares you mentally for vigorous activity 3. Helps maintain joint flexibility and reduces pain as you age 4. Helps prevent loss of function and inability to perform certain chores in the elderly, such as dressing, typing, and putting on shoes and socks

14. Assessment of Flexibility • Because range of motion is joint specific, no one test provides an accurate assessment of overall flexibility. • Modern tests generally include only the sit-and-reach test, which measures only lower-back and hamstring flexibility.

15. Stretching Techniques • Dynamic stretching—This technique involves the ability to use the range of joint movement during physical activity progressing from low to normal to high speed. • Ballistic stretching—This technique employs bouncing or bobbing at the extreme range of motion or point of discomfort. • Static stretching—This technique involves holding a stretch for 10 to 30 seconds to the point of some discomfort.

16. Other Techniques • Passive stretching—Use of a partner or special equipment to move body parts carefully and safely through the range of motion. • Proprioceptive neuromuscular facilitation (PNF) stretching—A two-person stretching technique involving the application of steady pressure by a partner at the extreme range of motion for a particular exercise and steady resistance to the pressure.

17. Who Should Stretch • People with lean body types and a high ROM may need very little stretching, whereas stocky, more powerfully built athletes with limited ROM need 10 to 15 minutes of flexibility exercise before making any radical moves. • Almost every healthy individual of any age or level of fitness can benefit from a regular stretching routine. • Even older individuals who live relatively sedentary lives can benefit from initiating a flexibility-training program.

18. When to Stretch • As part of a warm-up routine to prepare the body for vigorous activity • During the cool-down phase of a workout to help muscles return to a normal relaxed state • As a way to improve ROM in key joints • As an aid to rehabilitation after injury

19. Stretching to ImproveRange of Motion If your main purpose is to improve body flexibility, you can safely stretch any time you desire: • early in the morning, • at work, • after sitting for long periods of time, • after standing for long periods of time, • when you feel stiff, • after an exercise session, or • while you are engaged in passive activities such as watching television or listening to music.

20. Additional Stretching Notes • Stretching should involve a slow, relaxed, controlled, and pain-free movement. • To improve flexibility, you must remain in the hold position (static technique) at the end of the stretch for a minimum of 30 seconds for the stretch to progress from the middle of the muscle belly to the tendons. • Adults should stretch at least once daily 3 to 5 days per week to maintain flexibility. • Stretching should produce only mild discomfort.