PATHFIT

Anatomy

is the study of the structure of the body and the relationships among its parts.

It includes:

bones

muscles

joints

organs

nerves

tissues

Gross anatomy

Structures visible without a microscope

bones, muscles, organs

Microscopic anatomy

Structures requiring a microscope

cells and tissues

PHYSIOLOGY

is the study of how body structures function.

For movement, physiology explains:

muscle contraction

heart function

breathing

blood circulation

energy production

nervous-system control

fatigue

recovery

Biomechanics

applies principles of mechanics to the human body.

It examines:

forces

motion

balance

stability

acceleration

joint movement

torque

mechanical advantage

Kinematics

Describes what the movement looks like.

It does NOT focus on what causes the movement.

Examples:

position

displacement

velocity

acceleration

joint angle

range of motion

Kinetics

Studies the forces that cause or affect movement.

Examples:

muscle force

gravity

friction

ground reaction force

torque

FORCE

is a push or pull that can change the motion or shape of an object.

Basic equation:

F = ma

Where:

F = force

m = mass

a = acceleration

Newton's First Law — Law of Inertia

An object remains at rest or continues moving at constant velocity unless acted upon by an external force.

Movement example

A soccer ball remains stationary until a player kicks it.

Newton's Second Law

F = ma

The acceleration of an object depends on the force applied and its mass.

Example

A harder kick produces greater acceleration of the ball.

Newton's Third Law

For every action, there is an equal and opposite reaction.

Example

When jumping:

Feet push against the ground ↓

Ground pushes back against the body ↑

This upward force helps propel the person into the air.

This reaction is called the:

Ground Reaction Force (GRF)

Torque

is the rotational effect of a force around an axis.

Basic relationship:

Torque = Force × Moment Arm

Moment arm

The perpendicular distance between:

the axis of rotation

the line of action of the force

Important principle

The farther the force is from the axis:

→ larger moment arm

→ greater torque

Example

Opening a door is easier when you push farther from the hinges.

Center of Mass

The point where the body's mass can be considered concentrated.

Center of Gravity

The point through which the body's weight effectively acts.

For many practical human-movement situations, these concepts are closely related.

BASE OF SUPPORT

The area beneath and between the parts of the body supporting it.

Example

Standing with feet apart:

→ wider base of support

→ generally greater stability

Standing on one foot:

→ smaller base

→ generally less stable

Ball-and-socket joint

Examples:

shoulder

hip

Allows movement in many directions.

Hinge joint

Examples:

elbow

knee

Mainly allows:

flexion

extension

Pivot

Example:

atlantoaxial joint

Allows rotation.

Gliding

Example:

wrist/ankle regions

Allows sliding movements.

Pectoralis major

chest

helps move arm across body

Deltoid

shoulder

important in arm abduction

Biceps brachii

front upper arm

elbow flexion

Triceps brachii

back upper arm

elbow extension

Latissimus dorsi

back

assists shoulder movements

Rectus abdominis

trunk flexion

External/internal obliques

trunk rotation and lateral flexion

Erector spinae

spinal extension/postural support

Gluteus maximus

hip extension

Quadriceps

knee extension

Hamstrings

knee flexion

hip extension

Gastrocnemius

plantarflexion

Tibialis anterior

dorsiflexion

MUSCLE CONTRACTION

At the neuromuscular junction, the motor neuron releases acetylcholine (ACh). This initiates an electrical signal in the muscle fiber. Calcium is subsequently released, allowing myosin to interact with actin and generate contraction.

Nervous signal → acetylcholine → muscle action potential → Ca²⁺ release → actin-myosin interaction → contraction

Agonist / Prime mover

The muscle primarily responsible for a movement.

Antagonist

Muscle that opposes the prime mover.

Synergist

Assists the prime mover.

Fixator

Stabilizes part of the body so another movement can occur efficiently.

Isometric contraction

Muscle produces tension but joint movement is absent.

Example:

Holding a plank.

Muscles are working, but there is no obvious change in joint angle.

Concentric contraction

Muscle produces force while shortening.

Example:

Biceps during the lifting phase of a biceps curl.

Eccentric contraction

Muscle produces force while lengthening.

Example:

Biceps controlling the lowering phase of a curl.

Central Nervous System

Brain + spinal cord

Peripheral Nervous System

nerves outside the brain and spinal cord.

For voluntary movement:

Brain → spinal cord → motor neuron → skeletal muscle

The nervous system detects sensory information and activates appropriate bodily responses

Proprioception

awareness of body position and movement.

It helps you know:

where your limbs are

how your joints are positioned

how your body is moving

PHYSIOLOGICAL RESPONSE TO EXERCISE

↑ heart rate

↑ breathing rate

↑ breathing depth

↑ blood flow to active muscles

↑ body temperature

sweating

increased oxygen consumption

Heart rate

number of heartbeats per minute.

During exercise:

Exercise intensity ↑ → Heart rate ↑

Why?

Because working muscles require:

more oxygen

more nutrients

removal of metabolic waste

Cardiac Output

Heart Rate × Stroke Volume

Stroke volume = amount of blood pumped by the ventricle per beat.

Therefore:

If HR increases and stroke volume also increases:

cardiac output generally increases.

Muscle fatigue

= reduced ability of a muscle to maintain the required force or performance.

Possible contributing factors include:

prolonged exercise

energy depletion

metabolite accumulation

impaired excitation-contraction processes

inadequate recovery

dehydration/heat stress

Biomechanics

pplies principles of mechanics to biological movement.

It asks:

What forces cause movement?

examines:

force

motion

torque

balance

center of mass

momentum

acceleration

joint movement

Kinematics

Describes motion without focusing on its causes.

Includes:

position

displacement

velocity

acceleration

joint angles

Kinetics

Studies the forces causing motion.

Includes:

force

torque

gravity

ground reaction force

Gravity

is the force that attracts objects toward Earth.

It affects:

balance

jumping

running

landing

posture

projectile motion

Center of Mass

The point where the body's mass can be considered concentrated for analysis.

Center of Gravity

The point through which the resultant gravitational force acts.

For practical human movement analysis, these concepts are closely related.

BALANCE AND STABILITY

A person generally becomes more stable when:

base of support is larger

center of gravity is lower

line of gravity falls within the base of support

body mass is appropriately positioned

Example: defensive basketball stance

Athlete:

bends knees

lowers center of mass

widens stance

KINESIOLOGY

is the study of human movement.

It integrates:

anatomy

physiology

biomechanics

motor control

exercise science

Main goal

Understand how humans move and how movement can be improved.

Locomotor

Movement from one location to another:

walking

running

jumping

hopping

skipping

galloping

Non-locomotor

Movement without changing location:

bending

stretching

twisting

balancing

pushing

pulling

Manipulative

Controlling objects:

throwing

catching

kicking

striking

dribbling

MOVEMENT EFFICIENCY

An efficient movement:

uses appropriate muscles

minimizes unnecessary movement

maintains balance

uses appropriate force

has good coordination

uses appropriate technique

reduces unnecessary energy expenditure

minimizes injury risk

Movement competence

refers to having the ability, knowledge, and confidence to perform movement skills effectively and safely.

It includes:

skill

coordination

balance

control

confidence

appropriate technique

PHYSICAL ACTIVITY, MOVEMENT COMPETENCE, AND HEALTH

Movement competence

↓

Greater confidence and ability

↓

More participation in physical activity

↓ Improved physical fitness

↓ Better health

↓ Greater likelihood of lifelong activity

Physical activity contributes to:

cardiovascular health

muscular strength

endurance

flexibility

body composition

mental well-being

functional capacity

Young children

Emphasize:

basic locomotor skills

balance

coordination

simple games

exploration

Adolescents

Can progressively develop:

strength

endurance

agility

sport skills

fitness concepts

Older adults

Emphasize:

balance

mobility

functional strength

flexibility

fall prevention

appropriate aerobic activity

MOVEMENT + PHYSIOLOGY

Muscle activity increases

↓

Energy demand increases

↓

Oxygen demand increases

↓

Heart rate increases

↓

Cardiac output increases

↓

Blood delivery to active muscles increases

WARM-UP

prepares the body for physical activity.

It generally includes gradually increasing activity intensity and movement preparation.

Purposes

increase body temperature

increase blood flow

prepare muscles and joints

prepare nervous system

rehearse movement patterns

mentally prepare for activity

Dynamic stretching

Movement-based stretching.

Examples:

walking lunges

leg swings

arm circles

Useful as part of movement preparation.

Static stretching

Holding a muscle in a lengthened position.

Example:

holding a hamstring stretch for 20–30 seconds.

COOL-DOWN

s a gradual reduction in exercise intensity after activity.

Purposes

gradually transition toward resting state

continue light movement

provide opportunity for recovery

allow monitoring of symptoms

Example

After running:

Sprint → jog → walk → easy mobility

Flexibility

ability of a joint or group of joints to move through an available range of motion.

Factors affecting flexibility include:

joint structure

muscle length

connective tissue

temperature

age

activity level

Conditioning

develops the body's ability to perform physical activity.

Important components:

Cardiovascular endurance

Ability to sustain aerobic activity.

Muscular strength

Ability to produce force.

Muscular endurance

Ability to repeatedly produce/substantiate force.

Flexibility/mobility

Ability to move through appropriate ROM.

Body composition

Relative proportions of fat, muscle, bone, and other tissues.

Environment

heat

humidity

rain

slippery surfaces

obstacles

poor lighting

Equipment

proper shoes

appropriate clothing

safe equipment

properly inflated balls

functioning protective equipment

Participant

health status

fatigue

hydration

skill level

previous injury

SOFT TISSUE

include:

muscles

tendons

ligaments

skin

other connective tissues

Sprain

is an injury involving a ligament.

= ligament

Ligaments connect:

bone → bone

Common locations:

ankle

knee

wrist

fingers

Strain

involves a:

muscle

tendon

= muscle/tendon

Common causes:

overstretching

excessive force

lifting

sudden movement

overuse

Acute injury

Occurs suddenly.

Examples:

ankle sprain during basketball

pulled hamstring during sprint

fall

Chronic/overuse injury

Develops gradually from repeated stress.

Examples:

tendinopathy

repetitive strain

overuse injuries

R — Rest

Stop or reduce activity that causes pain.

I — Ice

Apply cold to help with pain and swelling.

Important safety:

don't place ice directly on skin

use a barrier

avoid excessive exposure

monitor the skin

C — Compression

Apply an elastic bandage to help control swelling.

Compression should be:

firm but not so tight that circulation is compromised.

E — Elevation

Raise the injured area when practical.

Purpose:

can help reduce swelling by promoting fluid return.

Ankle sprain

Step 1 — Stop activity

Don't continue playing through significant pain.

Step 2 — Assess

Look for:

pain

swelling

deformity

inability to bear weight

severe symptoms'

Step 3 — Rest/protect

Keep the injured ankle from unnecessary loading.

Step 4 — Cold application

Use a properly protected cold pack.

Step 5 — Compression

Apply elastic bandage appropriately.

Step 6 — Elevation

Raise the ankle when possible.

Step 7 — Monitor

Check symptoms and circulation.

FIGURE-EIGHT BANDAGE

is commonly used around joints such as the ankle.

General concept:

Wrap around the joint in crossing loops that form an "8."

Important safety rule:

Compression must not impair circulation.

Check:

skin color

warmth

sensation

comfort

swelling beyond the bandage

If the person develops:

numbness

tingling

increasing pain

pale/blue skin

coldness

→ loosen/remove the compression and reassess.

RED FLAGS

eans a sign that the injury may be serious and requires professional evaluation.

Important red flags include:

severe or worsening pain

major swelling

obvious deformity

inability to use the limb

inability to bear weight

loss of sensation

unusual weakness

Abrasion

A superficial injury caused by friction scraping the skin.

Example:

falling on concrete and scraping your knee.

Basic care

Ensure scene safety.

Use appropriate barrier protection.

Control bleeding with direct pressure if necessary.

Clean the wound with clean running water.

Remove visible dirt/debris if easily removable.

Cover with an appropriate clean dressing.

Monitor for infection.

burn

is tissue damage caused by:

heat

chemicals

electricity

radiation

other sources

Common thermal burns

Caused by:

hot water

steam

fire

hot surfaces

1. Remove the person from the source.

Ensure safety first.

2. Cool the burn with cool running water.

Avoid extremely cold/icy treatment.

3. Remove constricting items if not stuck.

Examples:

rings

bracelets

Because swelling may develop.

4. Cover appropriately.

Use a clean, non-stick dressing when appropriate.

MUSCLE CRAMPS

is a sudden, involuntary, painful muscle contraction.

Common during:

prolonged activity

heat exposure

fatigue

Possible contributing factors include:

muscular fatigue

dehydration

heat stress

electrolyte disturbances

Basic response

Stop or reduce activity.

Move to a safer/cooler environment if heat is involved.

Gently stretch the affected muscle.

Gently massage if comfortable.

Replace fluids as appropriate.

Monitor for signs of heat illness.

NOSEBLEED

pistaxis

Proper position

Sit upright and:

lean slightly forward.

Why forward?

To prevent blood from flowing backward into the throat.

Basic procedure

Sit upright.

Lean forward.

Pinch the soft part of the nose.

Maintain continuous pressure.

Monitor bleeding.

How Fatigue Affects Movement Efficiency

Force production decreases.

Proper technique becomes harder to maintain.

Compensatory movements may occur.

More energy may be required.

Injury risk increases.

Knee moves inward during squat

Keep knee aligned with the foot

Back rounds while lifting

Maintain a neutral spine

Excessive shoulder elevation

Relax shoulders and improve posture

Foot rolls excessively inward

Improve foot positioning and stability