bones, muscles, fibres & arrangements
4 types of synovial joints
Pivot, gliding, ball and socket, hinge, saddle and condyloid
Brain sends a message to muscles for contraction to occur. The electrical impulse reaches muscles and stimulates the myosin to attach to actin filaments.
Cross bridges then shorten and slide the actin filaments across.
Types of Injuries
Overuse - example: shin splints, tennis elbow
Acute Direct - example: concussion during head clash in a tackle in AFL
Acute Indirect - example: tearing an ACL after changing direction while running
3 types of physiological strategies to prevent injuries
PAR-Q Pre-screening - Physical Activity Readiness Questionnaire.
Physical Prep - Strength, flexibility, core training, to condition the body to be physically ready
Warm Up - prepare body, increases HR and blood flow
Cool Down - recover from exercise, break down waste products, reduces muscle soreness, return body to resting state
Legal Performance Enhancement Training Methods
Resistance training, short-interval, HIIT, plyometrics, continuous training, long-interval, fartlek training
Fibre Arrangement Types
Circular, Convergent, Parallel (fusiform), Parallel (non-fusiform), Pennate (Uni, Bi and Multi)
Reciprocol Inhibition
How muscles work in teams to allow efficient movement to occur. While once muscle contracts, the partnered muscle relaxes, allowing movement and reducing the risk of muscle tears
Agonist, Antagonists play a vital role, as do stabilisers.
Soft Tissue Sprain and Strains
Grade 1 - minimum number of fibres torn
Grade 2 - significant number of fibres torn
Grade 3 - complete tear of all fibres
Physical Aids - Physical Environment
Environment - heat, cold, UV, adequate rest periods, fluid, shade
Equipment - used incorrectly, dress code, inspection of facilities/equipment, uneven/poorly maintained surfaces
Legal Performance Enhancement - Nutritional Supplements
Sports foods/drinks
Medical supplements - calcium, vit D
Performance supplements - caffeine, protein, creatine, bicarb
Characteristics of Fast Twitch Fibres
examples - Fast Contraction, low fatigue resistance, larger muscle fibres, high force produced, low triglyceride stores
Muscle Actions
Isoinertial (Concentric, Eccentric) - change in length of muscle being moved through a range of motion
Isometric - contraction against a force w/o significant movement
Isokinetic - any force applied in equal reaction force supplied by a machine
Musculoskeletal Conditions
Osteoporosis - bone degradation exceeds bone regeneration
Arthritis types:
Osteoarthritis - degenerative bone disease
Rheumatoid Arthritis - autoimmune disease
Arthritis is caused by inflammation of the joints, causing pain, stiffness
Physical Aids - Protective Equipment and Taping/Bracing
Mouthguards, helmets, footwear, guards, eyewear
Sport-specific equipment designed to reduce or prevent musculoskeletal injuries
Taping/Bracing - joint stability, restrict movement, prevent sprains, kinaesthetic feedback to the brain, gives confidence
Illegal Performance Enhancement
Anabolic Steroids - increases strength, size, power, quicker recovery time
Human Growth Hormone - increase muscle strength/performance, quicker recovery.
Characteristics of Slow Twitch Fibres
Examples - Slow contraction, contract repeatedly for prolonged periods, smaller than fast twitch fibres, high triglyceride stores, low force produced
Motor Units & Size Principle
Size Principle - the amount of force used for a movement as controlled by HOW MANY motor units are recruited
Small movements = small increments of force & less motor units
Large movements = greater force, more motor units recruited
Hard Tissue Injuries
Fractures (open or closed):
Caused by direct trauma (collision) or indirect trauma (falling)
Dislocation/Sublaxations:
Injuries at the joint where the bones that form the joint are displaced. Caused by excessive movement at the joint.
Assist client with a Physical Aid - Has experienced shoulder dislocation reaching for rebounds in netball
Tape - to provide strengthen joint, confidence in joint
Ethical, Social & Cultural Considerations for Performance Enhancing
Personal - performance dissatisfaction, pressure, anxiety, keeping up ability level, "win at all costs" mentality
Sociocultural - financial reward, family/coach/public pressure, high demands for selection, drug culture in club/peers, national pride, role model influence
Functions of Muscles
Skeletal movement, posture, produce and release heat, store fuels
All or Nothing Principle
Nerve impulses don't stimulate the muscle fibres until it reaches a threshold.
When threshold reached - all fibres of the motor unit will contract at the same time.
Diagnose - a woman with consistent significant discomfort in her lower legs during runs on hard surfaces.
Shin Splints
Ensure surface is well maintained, adequate warm up, ensure adequate physical preparation (progression of activities to ensure the body is ready for sprinting)
Athletes/Clubs with a history of performance enhancing
Marion Jones, Lance Armstrong, Maria Sharapova, Essendon FC, Shane Warne, Alex Rodriguez, Joel Smith