Transcript Flexibility
Flexibility KIN 325 1. Definition The range of motion that can be elicited at a particular joint or group of joints Range of motion is highly specific; it differs between joints Also varies between people due to: • • • genetics and gender physical activity level joint structure • age • tissue injury • adipose tissue • body temperature 2. The benefits of a flexibility training program • Maintain good joint mobility, allowing for proper body mechanics • Reduce mechanical stress within the joints • Muscular relaxation • Relief of muscular cramps • Increase resistance to muscle injury • Improve and maintain good postural alignment • Prevent low-back and other spinal column problems 3. Connective Tissue: a limiting factor for flexibility Joint capsule and associated ligaments contribute approximately 47% to restriction of ROM; muscles contribute 41%, the tendons 10%, and skin 2% Stretching exercises help to cause minor distensions in connective tissue and summation of these small changes can improves ROM Increase in stretch tolerance 4. Sensory Receptors Related to Stretching a. Muscle spindles Primary stretch receptors in muscle, encased in a spindle-shaped capsule which is attached at both ends to the muscle fibers b. Golgi tendon organs Located at the muscle-tendon junction, not within the tendon. Main function is to monitor muscle tension 5. Stretching methods a. Ballistic stretching • Associated with bobbing or bouncing. Fast, dynamic stretches. Advantages: • • Develops dynamic flexibility Permits specificity of training Disadvantages • Quick stretch allows little time for adaptation. Permanent lengthening is most effectively achieved by lower force, longer duration stretches • Fast stretches create high tensile forces. Can result in injury or muscle soreness • Might elicit the stretch reflex. Causes muscle contraction, therefore increases tension. b. Static stretching • a static position held for a period of time Advantages: • muscle soreness minimized • injury risk minimized • more effective than ballistic stretching for increasing ROM Disadvantages: • Not specific to many movements where dynamic flexibility is required c. Proprioceptive Neuromuscular Facilitation (PNF) Incorporates various combinations of relaxation and contraction periods for the muscles being stretched The theory is that a simple reflex, initiated by the Golgi tendon organs during the contraction phase, will cause the muscle to relax more and offer less resistance to the stretch Contract-relax method - autogenic inhibition A variation of this method is the contract relax with agonist contraction (CRAC) technique – also incorporates reciprocal inhibition Advantages: Most research shows this method produces the largest gains in flexibility Also develops strength in the muscle as large forces are developed when the muscle is isometrically contracted in stretched position Disadvantages Elicits the most discomfort DOMS can result Greater risk of injury than with static stretching Usually requires a partner Not recommended for patients with CVD, as blood pressure might rise too high 6. Exercise Prescription Mode: static or PNF Frequency: at least 3 days per week Intensity: to point of discomfort, not pain Duration: 10 to 30 seconds each stretch Repetition: 3 to 5 for each stretch