Flexibility Chapter 12

Learning Objectives Be able to define flexibility. Know the factors that can limit the range of motion at a joint. Know the differences between static and dynamic flexibility. Understand the theory and implications of static, ballistic, and proprioceptive neuromuscular facilitation stretching methods.

Importance of Flexibility For athletes:  Need to be flexible in specific joints (varies with athletic activity) For non-athletes:  Contributes to efficient movement in walking and running  Prevents or relieves aches and pains common with aging

Factors That Limit Flexibility Bony structure (e.g., knee or elbow joints) Soft tissues including muscle, connective tissue, and skin (e.g., ankle or hip joints) Textbook is concerned primarily with connective tissue components of muscle tissue.

Static vs. Dynamic Flexibility Static flexibility:  Range of motion Dynamic flexibility:  Reflects joint stiffness and resistance to limb movement  Of greater importance in physical performance

Stretch Reflexes and Flexibility A muscle that is stretched with a jerky motion responds with a contraction (stretch reflex). A muscle that is stretched with a firm, steady, static stretch invokes the inverse myotatic reflex.

Static vs. Ballistic Stretching Static stretches:  Hold a static position for 30–60 seconds  Specified joints are locked into a position placing the muscles and connective tissues passively at their greatest possible length  Does not cause muscle soreness Ballistic stretches:  One body segment is put in movement by active contraction of a muscle group  Momentum is arrested by the antagonists at the end of the range of motion  Sometimes causes muscle soreness

Examples of Ballistic Stretching Methods See the full- sized figure on the AESP Resource Site.AESP Resource Site

Examples of Static Stretching Methods See the full- sized figure on the AESP Resource Site.AESP Resource Site

Proprioceptive Neuromuscular Facilitation (PNF) Stretching a muscle immediately after a maximal contraction Techniques are used by:  Athletes/non-athletes, to maintain or increase flexibility.  Clinical settings, to restore range of motion following injury. Common techniques: Contract–relax or contract–relax with agonist-contraction

Example of Contract-Relax (CR) PNF Stretching Method 1.Lie on your back and place towel around the bottom of one foot. 2.Fully straighten leg, lift until you feel moderate resistance. 3.Contract hamstring muscle for 5-10 seconds. 4.Pull on the towel to further stretch the hamstring muscle.

Your Perspective How do you prefer to stretch? Why do you prefer that particular method? Do you agree with studies that state that PNF methods are the most effective, or do you prefer one of the other methods? What would you recommend to someone who is trying to increase his or her flexibility?

General Guidelines for Stretching to Increase Flexibility Most effective when muscles are warm Should be performed before and/or after conditioning phase Stretching following exercise may be preferable for sports for which muscular strength, power, and endurance are important May not prevent injury Should be performed at least 2–3 days/wk. (continued)

More Guidelines for Stretching to Increase Flexibility Static, ballistic, and PNF stretching techniques improve flexibility. Stretching exercises should involve major muscle groups of the body. At least four reps per muscle group is recommended. Ballistic stretching may be considered for persons whose sports activities involve ballistic movements. Static stretches should be held for 15–60 seconds. A 6-sec. contraction followed by a 10- to 30-sec. assisted stretch is recommended for PNF techniques.

Factors Affecting Flexibility Activity Weight training Gender Age Temperature

Sit-and-Reach Flexibility Declines Throughout Adulthood

Your Perspective Imagine that you are a junior high school PE teacher. How would you assess your students’ flexibility? What kind of exercise program would you design to help your students gain greater flexibility?

Where to Learn More Types of stretching:  Stretching and flexibility:  PNF stretching:  Flexibility basics:  htm htm