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Chapter 3 Injury Prevention. Conditioning and Injury Prevention. Purpose – effective, physiologically appropriate physical conditioning program: Improve performance Minimize the risk of injury and illness Must understand basic principles of conditioning to ensure a program:
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Conditioning and Injury Prevention • Purpose – effective, physiologically appropriate physical conditioning program: • Improve performance • Minimize the risk of injury and illness • Must understand basic principles of conditioning to ensure a program: • Is safe and effective • Void of practices that could predispose the participant to injury
Basic Principles of Conditioning • Specific Adaptation to Imposed Demands (SAID) principle • Overload principle • Frequency: # exercise sessions per day or week • Intensity: amount of work during an exercise • Duration: length of a single exercise session
Flexibility • Total ROM at a joint that occurs pain free in each of the planes of motion • Combination of normal joint mechanics, mobility of soft tissues, and muscle extensibility
Flexibility (cont’d) • Mechanoreceptors influence flexibility • Muscle spindle • Lie parallel with contractile muscle fibers • Send sensory information to CNS • Muscle length • Velocity of length change • Excite/facilitate muscle contraction
Flexibility (cont’d) • Mechanoreceptors influence flexibility (cont’d) • Golgi tendon organs (GTO) • Lie in tendon, most at musculotendinous junction • Stimulated by stretch • Send sensory information to CNS • Muscle load and tension • Inhibit/relax muscle contraction
Stretching Techniques • Ballistic • Muscle spindle is stretched, but GTO do not fire; muscle resists relaxation • Momentum can lead to overstretching, tearing • Static • GTO override impulses from the muscle spindles • Safer, more effective muscle stretch
Stretching Techniques (cont’d) • Proprioceptive neuromuscular facilitation (PNF) • Involves stimulation of the proprioceptors • flexibility in one muscle group (i.e., agonist), and simultaneously strength in another group (i.e., antagonist) • Techniques • Active inhibition • Reciprocal inhibition
Stretching Techniques (cont’d) • PNF (cont’d) • Advantages • Early use • Single plane or diagonal patterns • Overload principle can be used to achieve or maintain normal flexibility
Muscular Strength and Endurance • Muscular strength • Ability of a muscle or group of muscles to produce force in one maximal effort • Muscular endurance • Ability of muscle tissue to exert repetitive tension over an extended period
Muscular Strength and Endurance (cont’d) • Muscular strength and endurance depends on: • Number and size of muscle fibers • Type of muscle fiber (slow twitch; fast twitch) • Neuromuscular coordination • Gender
Static Strength vs. Dynamic Strength • Isometric contraction • Tension is produced by the muscle, but there is no change in muscle length • Concentric contraction • Shortening; decreases joint angle • Work to accelerate a limb
Static Strength vs. Dynamic Strength (cont’d) • Eccentric contraction • Lengthening; increases joint angle • Work to decelerate a limb and provide shock absorption
Dynamic Strength • Isotonic exercise • Variable speed/fixed resistance • Advantages • Permits exercise of multiple joints simultaneously • Allows both eccentric & concentric contractions • Permits weight-bearing, CKC exercises
Dynamic Strength (cont’d) • Isotonic exercise (cont’d) • Disadvantage • When a load is applied, the muscle can only move that load through the ROM with as much force as the muscle provides at its weakest point
Dynamic Strength (cont’d) • Isokinetic exercise • Fixed speed/variable resistance • Advantages • 100% loading throughout ROM • Pain disengages mechanism
Dynamic Strength (cont’d) • Isokinetic exercise (cont’d) • Disadvantages • As muscle fatigues, resistance decreases • Most machines only permit concentric contraction • $$$$
Strength Application Principles • Strength gains depend primarily on the intensity of the overload • Endurance improvement will be determined by the intensity and duration of exercises • Frequency • Intensity • Duration
Cardiorespiratory Endurance • Body’s ability to sustain submaximal exercise over an extended period • Cardiovascular level impacts fatigue • Detraining occurs within 1 to 2 weeks • Generally considered the most important component of any fitness program • ACSM recommends • Activity 3-5 days per week • > 20 minutes • Intensity of 60-90% of maximal heart rate (HRmax)
Check for Understanding! The fitness component that is generally considered to be the most important is: • Muscular strength • Flexibility • Muscular endurance • Cardiovascular endurance
Check for Understanding! The principle of overload is achieved by manipulating which of the following components of an exercise program? (select all that apply) • Endurance • Duration • Intensity • Frequency • Specificity
Check for Understanding! During a ballistic stretch, which of the following are activated? • Muscle spindle • Golgi tendon organ • Fast twitch fibers • Slow twitch fibers
Check for Understanding! The ability of muscle tissue to exert repetitive tension over an extended period is termed: • Cardiovascular endurance • Muscular strength • Muscular endurance • Flexibility
Proper Technique and Injury Prevention • Proper technique is important with regard to: • Efficient and effective skill performance • The prevention of injury • Coach is responsible to teach proper skill technique and to continually reinforce the use of proper technique • The instruction and expectation of performance of any skill needs to be age and developmentally appropriate
Protective Equipment and Injury Prevention (cont’d) • Specialized equipment can protect a participant from accidental or routine injuries • Coach can share or be solely responsible to ensure that protective equipment: • Meets minimum standards of protection • Is in good condition, clean, properly fitted, and used routinely • Used as it was intended
Principles of Protective Equipment • Protection from forces • High velocity–low mass: focal injury • Low velocity–high mass: diffuse injury
Principles of Protective Equipment (cont’d) • Design factors that can reduce potential injury • Increase impact area • Disperse impact area to another body part • Limit the relative motion • Add mass to the body part • Reduce friction • Absorb energy • Resist the absorption of bacteria, fungi, and viruses
Liability and Equipment Standards • Organization’s duty to ensure the proper use of protective equipment is usually a shared responsibility among the athletic staff
Liability and Equipment Standards (cont’d) • Some settings, coach may be legally responsible for: • Selecting the most appropriate equipment • Properly fitting the equipment to the individual • Instructing the individual in proper care for the equipment • Warning the individual of any danger in using the equipment inappropriately • Supervising and monitoring the proper use of all protective equipment • Even if an individual provides their own
Liability and Equipment Standards (cont’d) • Standards of quality agencies • NOCSAE • Football, baseball, softball, and lacrosse helmets and facemasks • Other equipment (i.e., protective eye wear, ice hockey helmets, and facemasks) • ASTM • HECC • CSA
Liability and Equipment Standards (cont’d) • Athletic governing bodies • Establish rules for the mandatory use of specific protective equipment • Determine rules governing special protective equipment • NFSHSA, NAIA, NCAA, USOC
Protective Equipment: Head and Face • Football helmets • Can reduce head injuries, but do not prevent neck injuries due to axial loading • Construction • Single or double air bladder, closed-cell padded, or combination • Shell – plastic or polycarbonate alloy
Protective Equipment:Head and Face (cont’d) • Football helmets (cont’d) • Effect of heat • NOCSAE warning • Fitting – follow manufacturer’s guidelines • Paperwork
Protective Equipment:Head and Face (cont’d) • Ice hockey helmets • Can reduce head injuries, but do not prevent neck injuries due to axial loading • Must absorb and disperse high-velocity, low-mass forces • CSA approved
Protective Equipment:Head and Face (cont’d) • Batting helmets • NOCSAE approved • Double ear flap design • Other helmets • Lacrosse • Bicycle
Protective Equipment:Head and Face (cont’d) • Face guards • Protect and shield facial region • Football • Effectiveness depends on the strength of the guard, the helmet attachments, and the four-point chin strap on the helmet • Proper fit
Protective Equipment:Head and Face (cont’d) • Face guards (cont’d) • Ice hockey • Made of clear plastic, steel wire, or combination • HECC and ASTM standards • Proper fit • Lacrosse • Made of wire mesh • NOCSAE standards
Protective Equipment:Head and Face (cont’d) • Eye wear • Goggles • Face shields • Spectacles
Protective Equipment:Head and Face (cont’d) • Mouth guards • Reduce dental and oral soft tissue injuries and, to a lesser extent, jaw fractures, cerebral concussions, and TMJ injuries • Proper fit
Protective Equipment:Throat and Neck • Attachable throat guard • Required for catchers in baseball and softball • Cervical rolls and collars • Designed to limit motion of cervical spine • Effective in preventing burner, but properly fitted shoulder pads are critical • Do not decrease axial loading on the cervical spine when the neck is flexed
Protective Equipment:Upper Body • Shoulder pads • Should protect the soft and bony tissue structures in the shoulder, upper back, and chest • Construction • Select on player position, body type, and medical history
Protective Equipment:Upper Body • Shoulder pads (cont’d) • Types • Cantilever: protect AC joint and distribute forces throughout entire shoulder girdle • Flat: provide less protection to shoulder region, but permit more glenohumeral motion
Protective Equipment:Upper Body • Elbow, forearm, wrist, and hand • Protection from external forces • Thorax, ribs, and abdomen • Protection from external forces
Protective Equipment:Upper Body • Lumbar/sacral protection • Weight training belts; abdominal binders • Should support the abdominal contents, stabilize the trunk, and prevent spinal deformity or injury during heavy lifting
Protective Equipment:Lower Body • Hip and buttock region • Protect the iliac crest, sacrum, coccyx, and genital region • Pads typically composed of hard polyethylene covered with layers of Ensolite™ • Girdle with pockets can hold pads in place
Protective Equipment:Lower Body (cont’d) • Thigh • Pad: protect quadriceps • Neoprene sleeves: provide compression, therapeutic warmth, & support for quadriceps or hamstring strain
Protective Equipment:Lower Body (cont’d) • Knee braces • Prophylactic • Protect the MCL • Redirect lateral valgus force to points distal to the joint • Functional • Provide proprioceptive feedback • Protect ACL
Protective Equipment:Lower Body • Knee braces • Rehabilitative • Provide immobilization at a selected angle • Permit controlled ROM through predetermined arcs • Prevent accidental loading in non-weight bearing activity
Protective Equipment:Lower Body (cont’d) • Knee braces