© 2010 Cengage-Wadsworth Chapter 8 Muscular Flexibility Outline: 1.Benefits of Good Flexibility...

© 2010 Cengage-Wadsworth

Chapter 8Muscular

Flexibility

Outline:1.Benefits of Good Flexibility2.Factors Affecting Flexibility3.Assessment of Flexibility4.Evaluating Body Posture5.Principles of Muscular Flexibility Prescription6.When to Stretch?7.Flexibility Exercises8.Preventing & Rehabilitating Low-Back Pain


1 2 3 4 5 6 7 8

Muscular Flexibility

• When joints are not regularly moved through their full range of motion, muscles and ligaments shorten over time, and flexibility decreases

• Repetitive movement through regular/ structured exercise as in running, cycling, or aerobics without proper stretching causes muscles and ligaments to tighten


1 2 3 4 5 6 7 8


• Flexibility is the achievable range of motion at a joint or group of joints without causing injury

• Some muscular/skeletal problems and injuries, related to a lack of flexibility, occur when a tight muscle is abruptly forced beyond its achievable range of motion

• A decline in flexibility can lead to poor posture and aches and pains that lead to limited, painful joint movement


1 2 3 4 5 6 7 8


• 80% of all low-back problems in the U.S. result from improper alignment of the vertebral column and pelvic girdle as a direct result of inflexible and weak muscles

• This backache syndrome costs U.S. industry billions yearly in lost productivity, health services, and worker compensation


1 2 3 4 5 6 7 8

Benefits of Good Flexibility

• Promotes healthy muscles and joints• Improves elasticity of muscles and connective tissue around joints, enhancing freedom of movement

• Makes activities of daily living (turning, lifting, and bending) easier to perform

• Regular stretching increases circulation to the muscles

• Helps prevent low-back and other spinal column problems


1 2 3 4 5 6 7 8

Benefits of Good Flexibility

• Improves and maintains good postural alignment

• Promotes proper and graceful body movement

• Improves personal appearance and self-image

• Helps develop and maintain motor skills throughout life


1 2 3 4 5 6 7 8

Flexibility in Older Adults

• Older adults lose mobility and may be unable to perform simple tasks such as bending forward or turning

• Individuals who lose range of motion with age are unable to look over their shoulder to switch lanes or parallel park, increasing the risk for automobile accidents

• Lack of good range of motion can severely hamper physical activity and exercise


1 2 3 4 5 6 7 8

Flexibility in Older Adults

• Lack of flexibility may cause falls and other injury

• A simple stretching program can alleviate or prevent this problem and help people return to an exercise program


1 2 3 4 5 6 7 8

Factors Affecting Flexibility

• Genetic factors• Physical activity• Joint structure (shape of the bones)

• Joint cartilage• Ligaments• Tendons

• Muscles• Skin• Tissue injury• Adipose tissue (fat)

• All influence range of motion about a joint


1 2 3 4 5 6 7 8


• Body temperature• Age• Gender• All affect flexibility


1 2 3 4 5 6 7 8


• Changes in muscle temperature can increase or decrease flexibility by as much as 20%– Warm muscles are more flexible– Cool temperatures impede range of motion

• Flexibility is affected by the amount of adipose tissue (fat) in and around joints and muscle tissue

• Excess adipose tissue increases resistance to movement, and the added bulk hampers joint mobility because of the contact between body surfaces


1 2 3 4 5 6 7 8


• Women are more flexible than men and retain this advantage throughout life

• Aging decreases extensibility of soft tissue, resulting in less flexibility in both sexes

• Sedentary living is the most significant contributor to lower flexibility because muscles lose elasticity and tendons and ligaments tighten and shorten

• Adipose tissue increases with inactivity, which decreases a joint’s range of motion

• Injury to muscle tissue and tight skin from excessive scar tissue negatively effect range of motion


1 2 3 4 5 6 7 8

Evaluating Body Posture

• Good posture enhances– Personal appearance– Self-image– Confidence– Improves balance and endurance– Protects against misalignment-related aches and pains

– Prevents falls– Enhances overall sense of well-being


1 2 3 4 5 6 7 8

Evaluating Body Posture

• Poor posture is a risk factor for musculoskeletal problems of the neck, shoulders, lower back, and strains the hips and knees

• Bad posture, weak and inelastic muscles are a leading cause of chronic low-back problems

• Proper body mechanics means using correct positions in all activities of daily life, including sleeping, sitting, standing, walking, driving, working, exercising


1 2 3 4 5 6 7 8

Principles of Muscular Flexibility Prescription

• Although genetics play a crucial role in flexibility, range of joint mobility can be increased and maintained through a regular stretching program

• Since range of motion is highly specific to each body part, a comprehensive stretching program should include all body parts and follow basic guidelines for flexibility development


1 2 3 4 5 6 7 8

Principles of Muscular Flexibility Prescription

• Overload and specificity of training principles apply to the development of flexibility

• To increase total range of motion of a joint, the specific muscles around the joint must be stretched progressively beyond their normal length

• Principles of mode, intensity, repetitions, and frequency of exercise apply


1 2 3 4 5 6 7 8

Modes of Training

• Three modes of stretching exercises can increase flexibility– Ballistic stretching– Slow-sustained stretching– Proprioceptive neuromuscular facilitation (PNF) stretching

• Research shows all three types improve flexibility

• Each technique has certain advantages


1 2 3 4 5 6 7 8

Ballistic Stretching

• Ballistic (or dynamic) stretching: Exercises done with jerky, rapid, bouncy movements

• May cause muscle soreness and injury from small tears to the soft tissue

• Precautions must be taken not to overstretch ligaments because they undergo plastic or permanent elongation which leads to excessively loose joints, increasing the risk for injuries

• Slow, gentle, controlled ballistic stretching is effective in developing flexibility

• Most people can perform it safely


1 2 3 4 5 6 7 8

Slow-Sustained Stretching

• Slow-sustained stretching: Exercises in which the muscles are lengthened gradually through a joint’s complete range of motion and the final position is held for a few seconds

• Relaxes muscles, achieving greater length

• Low risk for injury• Most frequently used and recommended


1 2 3 4 5 6 7 8

Proprioceptive Neuromuscular Facilitation (PNF)

• Proprioceptive neuromuscular facilitation (PNF): Stretching technique that uses reflexes and neuromuscular principles to relax the muscles being stretched

• Based on a “contract-and-relax” method

• Partner assisted


1 2 3 4 5 6 7 8


• Procedure is as follows:– Assistant provides initial force by slowly pushing in the direction of the desired stretch

– Person being stretched then applies force in the opposite direction of the stretch, against the assistant who tries to hold the initial degree of stretch, resulting in an isometric contraction at the angle of the stretch

– The contraction is held 4-5 seconds, then the person being stretched relaxes the muscles and the assistant slowly increases the stretch

– The procedure is repeated – Steps 1-4 are repeated 2-5 times with the final stretch position held for 15-30 seconds


1 2 3 4 5 6 7 8

Proprioceptive neuromuscular facilitation (PNF) stretching technique: (a) isometric phase (b)

stretching phase


1 2 3 4 5 6 7 8


• Theoretically, the isometric contraction helps relax the muscle being stretched, which results in lengthening the muscle

• Increases strength of the muscle being stretched from the isometric contraction

• Data shows about 17% and 35% increase in absolute strength and muscular endurance in the hamstring group after 12 weeks of PNF

• Results were consistent in men and women• Disadvantages of PNF are more pain, the need for a partner, time consuming


1 2 3 4 5 6 7 8

Intensity

• Degree of stretch to the point of mild discomfort or tightness at the end of the range of motion

• All stretching should be done slightly below the pain threshold

• Participants should try to relax the muscle being stretched

• If you feel pain, the load is too high and may cause injury


1 2 3 4 5 6 7 8

Repetitions

• Time required for a flexibility session is based on the number of repetitions and the length of time each repetition is held in the final stretched position

• General recommendation– Each exercise should be done 2-4 times– Each time hold the final position 15-30 seconds– Gradually increase the time each repetition is held to a maximum of 1 minute

• Individuals susceptible to flexibility injuries should limit each stretch to 20 seconds

• Pilates exercises are recommended for these individuals to increase joint stability


1 2 3 4 5 6 7 8

Frequency of Exercise

• Flexibility exercises should be performed a minimum of 2-3 days per week, ideally 5-7 days per week

• After 6-8 weeks, flexibility can be maintained with only 2-3 sessions per week of 3 repetitions of 15-30 seconds each


1 2 3 4 5 6 7 8

When to Stretch

• Warming up means starting a workout slowly followed by gentle stretching (not through entire range of motion)

• A warm-up that progressively increases muscle temperature and mimics movement that will occur during training enhances performance


1 2 3 4 5 6 7 8

When to Stretch

• Gentle stretching with warm-up recommended for some activities– 3- to 5-minute warm-up for steady activities

– Up to 10 minutes for stop-and-go activities and athletic participation in general

• Extensive stretching prior to performing events that rely on strength and power for peak performance is not recommended


1 2 3 4 5 6 7 8

When to Stretch

• Evidence is unclear regarding whether stretching before or after exercise is best for injury prevention

• Good time to stretch is after aerobic exercise due to higher body temperature

• Stretching helps fatigued muscles reestablish their normal resting length and prevent unnecessary pain


1 2 3 4 5 6 7 8

Preventing & Rehabilitating Low-Back Pain

• Over 95% of all back pain is related to muscle/tendon injury

• 1%-5% is related to intervertebral disc damage

• Most common cause of low-back pain is physical inactivity, particularly sitting, which causes back muscles to shorten, stiffen, and weaken


1 2 3 4 5 6 7 8

Incorrect & correct pelvic alignment

• Weakening of the abdominal and gluteal muscles, along with tightening of the lower back muscles, causes an unnatural forward tile of the pelvis resulting in lower back pain

• Pelvis tilt is aggravated by fat around the midsection


1 2 3 4 5 6 7 8

Effects of Stress

• Excessive stress causes muscles to contract

• Frequent tightening of the muscles can throw the back out of alignment and constrict blood vessels that supply oxygen and nutrients to the back

• Chronic stress releases hormones linked to muscle and tendon injuries

• People under stress forget about proper body mechanics, increasing risk for injury

• Proper stress management should be in your back care program


1 2 3 4 5 6 7 8

Personal Flexibility & Low-Back Conditioning Program

• Recommendations call for isometric contractions of 2-20 seconds during each repetition for some exercises for back health

• Length of the hold will depend on your current fitness level and difficulty of each exercise

• Most exercises begin with a 2-10 second hold

• After several weeks increase the hold to 30 seconds

© 2010 Cengage-Wadsworth Chapter 8 Muscular Flexibility Outline: 1.Benefits of Good Flexibility...

Documents

Transcript of © 2010 Cengage-Wadsworth Chapter 8 Muscular Flexibility Outline: 1.Benefits of Good Flexibility...