Muscular Control of Movement

Review of Anatomy Types of Muscles –Smooth: blood vessels and organs –Cardiac: heart –Skeletal: muscles for movement

Review of Anatomy Skeletal Muscle –600 Skeletal Muscles –Voluntary Movement –Origin / Insertion –75% H2O, 20% Prot.

The Structure of Skeletal Muscle Epimysium –Covers the entire muscle Perimysium –Covers the Fasciculi Endomysium –Covers the muscle fiber Sarcoplasm –Surrounds the myofibril

The Structure of a Muscle Cell Sarcoplasm –Transverse Tubules –Sarcoplasmic Reticulum Myofibril –Sarcomere Myosin (heads) Actin (tropomyosin, troponin)

The Sliding Filament Theory Motor nerve impulse –motor nerve releases ACh to sarcolemma Depolorization causes chain reaction –sarcoplasmic reticulum releases calcium –calcium binds with troponin –troponin lifts tropomyosin –myosin heads bind with actin (cross bridge) Power Stroke: is the tilting of the myosin head

The Sliding Filament Theory Energy is required for muscle action –the myosin head binds to ATP, and ATPase found on the head splits ATP into ADP and P, releasing energy for muscle contraction. Calcium releases for muscle relaxation –calcium is pumped out of the sarcoplasm and back into the sarcoplasmic reticulum for storage, which requires ATP.

Slow Twitch vs Fast Twitch STo slow ATPase small SR small motor neuron less fibers per unit aerobic endurance red color - capillaries B oxidation enzymes FTa, FTb, FTc fast ATPase large SR large motor neuron more fibers per unit anaerobic power pink or white in color glycolytic enzymes

Muscle Fiber Recruitment Motor units: consists of a single motor neuron and all of the muscle fibers is supplies. All-or-None Response: Gradation of recruitment –force production: is due to the number of fibers recruited, not the force generated by each fiber –conditioning response: training effects the coordination and recruitment of muscles for specific activities FTb & FTc fibers aren’t easily recruited

Generation of Force number of motor unit types of motor units size of the muscle muscles initial length angle of the joint muscle’s speed stretch reflex

Use of Muscles Types of Movement –agonists –antagonists –synergists Types of Contraction –concentric –static –eccentric

Requirements For Large Muscle Development Proper Nutrition –65% CHO, 20% Fat, 15% Protein Resistance Training Genetics Hormonal Secretion Levels –testosterone –androgens

ACSM Strength Guidelines Frequency = 2-3 days/week Intensity –85% of max for strength –75% of max for muscular power + (method) –50% - 65% of max for muscular endurance Time = – sec. per set / reps per set –work to rest ratio 1:4 Specificity = resistance type

Strength Training Myths Strength training will cause “muscle boundness” Women who strength train will become masculinized Strength training reduces speed “No pain - No gain” It takes hours of daily training to gain muscle mass Food supplements will speed up muscle development Anabolic steroids are safe and effective Amino Acids are safe and effective

Types of Training IsometricIsotonicIsokineticPlyometrics

Modes of Training Free weights NautilusHydraulicsFriction Rubber tubing CybexBow-flexBox-jumpsHydrotherapyEtc.