EF205 Scientific Foundations of Exercise and Fitness Unit 2

Today’s Agenda  Quick Review and Look Ahead  Lecture  Summary and Q & A

Quick Review  What did we study last week?

Quick Review  What did we study last week? PA and exercise recommendations Difference between PA and Exercise Components of physical fitness Components of performance Health, PA and exercise on a continuum

Why is knowledge of Anatomy important?

 To understand muscle forces  To be able to apply biomechanics to human movement  To be able to instruct safe and effective exercise programs  To communicate with other professionals  To earn respect of clients

Joints  Synarthrodial (Immovable) Sutures of the skull  Amphiarthodial (slightly moveable) SI joint  Diarthrodial (synovial or freely moveable) Hip, elbow, knee, etc

The structure of joints determines what movements take place

Joint Structure  Articular cartilage Found at the ends of bones Reduces friction and absorbs shock  Articular capsule Encloses each joint Is a ligamentous structure  Synovial membrane Lines the inner surface of the capsule Secretes fluid to lubricate joint  Periosteum Connective tissue surrounding all bone surfaces except articulating surfaces

Diarthrodial Joints  Gliding joints 2 plane or flat bony surfaces which butt against each other Little motion possible in any 1 joint articulation Usually work together in series of articulations

 Gliding joints Ex. Vertebral facets in spinal column, intercarpal & intertarsal joints Motions combine for lots of movement Diarthrodial Joints Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw-Hill.

Diarthrodial Joints  Hinge joint motion in only one plane Ex. Elbow, knee Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw-Hill.

Diarthrodial Joints  Pivot joint  Ex. atlantoaxial joint, proximal & distal radio- ulnar joints Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw-Hill.

Diarthrodial Joints  Condyloid (Knuckle Joint) one bone with an oval concave surface received by another bone with an oval convex surface

Diarthrodial Joints  Condyloid (Knuckle Joint) EX. 2nd, 3rd, 4th, & 5th metacarpophalangeal or knuckles joints, wrist articulation between carpals & radius flexion, extension, abduction & adduction (circumduction) Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw- Hill.

Diarthrodial Joints  Ball & socket joint Bony rounded head fitting into a concave articular surface Ex. Hip & shoulder joint Motions are flexion, extension, abduction, adduction, diagonal abduction & adduction, rotation, and circumduction Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw-Hill.

 Saddle Joint 2 reciprocally concave & convex articular surfaces Only example is 1 st carpometacarpal joint at thumb Flexion, extension, adduction & abduction, circumduction & slight rotation Diarthrodial Joints Modified from Booher JM, Thibedeau GA: Athletic injury assessment, ed 4, New York, 2000, McGraw-Hill.

Question: Which joints have the most mobility?

 Shoulder and hip

Question: Which joint is more stable, the shoulder or the hip?

 Due to joint structure, the hip has more stability, the shoulder has more mobility  The price of mobility is reduced stability  The more mobile a joint is, the less stable it is & the more stable it is, the less mobile

Important things to know about: Muscles  They don’t push, they only pull  Help to stimulate bone growth via Wolf’s Law A bone remodels itself based on the stress and loads placed on it  Part of FFM (fat free mass)  More metabolically active

More terminology…  Tendons attach muscle to bone We STRAIN tendons and muscles  Ligaments attach bone to bone We SPRAIN ligaments

Muscle Actions  Concentric (positive) Muscle shortens and pulls the bones closer together Occurs when muscle applies force as it shortens What we typically think of when we refer to muscle contractions Known as the positive Examples: elbow flexion (bicep curl), knee flexion (hamstring curl), etc

 Eccentric: (Negative) Occurs when muscle applies force as it lengthens Associated with more muscle soreness Known as the negative It is the controlling or lowering phase of movement Muscle lengthens while producing force Examples: lowering phase of bicep curl, lowering phase of hamstring curl, etc Types of Muscle Contractions

Muscle Actions, cont.  Isometric (static) No movement at the joint Muscle exerts force, but there is no change in the joint position Examples: bridge, plank, arm wrestling, etc

Joint Movements  Flexion-Anterior or posterior movement from anatomical position that brings two bones together  Extension-return from flexion  Hyperextension-continuation of extension past anatomical position

Joint Movements, cont.  ABduction-movement of a bone laterally from anatomical position  ADduction-return back to anatomical position  Rotation-when a bone spins around its longitudinal axis  Circumduction-combination of flexion, extension, ABduction and ADduction

Agonist  Also termed the ‘prime mover’  The muscle that is most responsible for the movement that is occurring Examples: what is the prime mover in a bicep curl? Bench press? Leg extension?

Assisting Muscles  Help the prime mover (agonist) with the movement.  It is not the prime mover, but it does quite a bit of work  Examples: What is the assisting muscle in the bench press? Triceps extension?

Antagonist  The muscle opposite the agonist  The antagonist does the exact opposite movement  Examples: What is the antagonist in a bicep curl? Bench press? Leg extension?

Stabilizers  These muscles stabilize a joint so that a movement can take place at another joint.  Many times this is an isometric contraction Examples: What are the stabilizing muscles when doing a chest press? Bent over barbell row?

Review for Quiz  Know terminology and definitions  Be able to determine what type of muscle contractions and muscle actions are taking place during different joint movements

Wrap Up  Summary  Q & A