Anatomy and movement analysis Flashcards
Functions of the skeleton (5)
Support Protection Movement Blood production Mineral storage
Two skeletons
Axial skeleton - vertebral column, rib cage and cranium which provide support for:
Appendicular skeleton- shoulder, hip girdle, arms and legs
Five types of bone
Long Short Irregular Flat Sesamoid
Long bones
Cylindrical shape, in limbs act as levers
E.g fémur, radius,, tibia, fibula
Short bones
Compact shape. Weight bearing.
E.g tarsals, carpals, phalanges
Irregular bones
Complex shape for protection and multiple muscle attachments.
E.g vertebrae
Flat bones
Smooth even surface to protect vital organs
E.g ribs, cranium
Sesamoid bones
Small oval within tendons to prevent injury
E.g patella
3 types of soft tissue
Ligaments
Tendons
Cartilage
What are ligaments
Strong fibrous tissue that connects bone to bone. Stabilises joint to allow specific movements.
What are tendons
Strong elastic tissue made of collagen that attaches muscle to bone. Transmita force to cause movements.
What is cartilage
Firm, resilient matrix of connective tissue with no blood supply.
3 types of cartilage
Yellow elastic cartilage- pliable, flexible (ears, nose)
White fibrocartilage - tough, thick tissue acting as shock absorber (knee meniscus and invertebral column)
Articular (hyaline) cartilage- surrounds surface of articulating bones to prevent friction at joint. Exercise thickens articular cartilage.
3 types of joint
Fibrous (fixed) - very stable, not allow movement (cranium)
Cartilaginous - rigid but slightly movable (vertebrae)
Synovial - allow wide range of movement (knee, shoulder, elbow)
Types of synovial joint
- Hinge- uniaxial structure- movement back and forwards (elbow)
- Pivot- uniaxial- rotation (atlas and axis in neck)
- Ellipsoid/Condyloid - biaxial - back and forth and side to side (wrist)
- gliding - biaxial - (tarsals (thumb))
- saddle - biaxial - (thumb)
- ball and socket - triaxial structure - side to side, forwards and back and rotation (shoulder, hip)
Functions of skeletal muscle
Movement
Support
Posture (muscle tone)
Heat production
Origin, insertion points
Origin is the end of the muscle that attach to fixed bone.
Insertion point is the other end which pulls on a different bone to cause movement.
Muscle pairs
Agonist = muscle that contracts to allow movement.
Antagonist = muscle that relaxes to allow movement.
Synergist = muscle that aids agonist
Fixators = muscles that stabilise joint in movement
Types of muscle contractions
Concentric isotonic - muscle shortens under tension.
Eccentric contraction - muscle lengthens under tension. Generally when movement is down/body is fighting gravity.
Isometric contraction - muscle remains same length. Stationary.
Planes and axis pairs and corresponding movements
Frontal plane + frontal axis - abduction/adduction
Sagittal plane + transverse axis - flexión/extension
Transverse plane + Longitudinal axis - horizontal abduction/adduction
Levers
Produce a turning movement around a fixed point.
1,2,3 F,L,E
1st class levers
Fulcrum in middle
Good for producing speed
2nd class levers
Resistance in the middle
Generate great force
3rd class levers
Effort in middle
Producing a wide range of movement
Mechanical efficiency
RA bigger than EA = advantage in range of movement but disadvantage in strength.
EA bigger than RA = advantage in strength but only has small range of movement.
Factors affecting stability
1) height of centre of mass
2) position of line of gravity
3) area of base of support
4) mass of a performer
What is centre of mass
The point of balance within a body. Hard to locate in humans(irregular). In sport body is always moving so COM is constantly changing.
High COM ⬇️ stability
What is Line of gravity
Imaginary line extending vertically down from COM.
Stability ⬆️ if line of gravity is kept central over base of support.
What is base of support
It is determined by the number of contact points.
The larger the area of the base of support the ore stable the position.
What is inertia
The resistance of a body to change its state of motion.
As soon as a body overcomes inertia it has momentum.
What is momentum
The amount of motion a body possesses.
Newton’s first law
Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
Known as law of inertia.
Newton’s 2nd law
The acceleration of an object or body of constant mass is directly proportional to the force acting on it.
Force= mass x acceleration
Known as the law of acceleration.
Newton’s 3rd Law
For every action there is an equal and opposite reaction.
Known as the law of reaction.
Most common application is a persons body weight causes a ground reaction force.
Momentum
The amount of motion a body possesses.
=mass x velocity
Impulse
The length of time a force is applied to an object.
=force x time
It is equal to change in momentum.
Impact
A high force or shock applied over a short time period when two bodies collide.
It is a short and forceful impulse.
A larger force over a shorter time has a greater effect in sport.
Impulse during a sprint race
1) driving off the blocks = positive impulse
2) accelerating over the first 10m = net positive impulse
3) mid-race constant velocity = zero impulse
4) decelerating over finish line = net negative impulse
