PE SAC Revision

Physical activity

any bodily movement produced by skeletal muscles that requires energy expenditure.

Barriers

Factors that stop or inhibit people's participation in physical activity.

Enabler

Refers to factors that encourage individuals to participate in physical activity

Ligaments

Connect bone to bone

Tendon

Connect muscle to bone

Skeletal muscles

Voluntary, striated muscles attached to bones via tendons that contract to facilitate movement.

Smooth muscles

Refers to involuntary, non-striated (smooth) muscles found in the walls of internal organs.

Cardiac muscles

Involuntary, striated muscle that make up the walls of the heart.

Reciprocal inhibition

The process where the agonist contracts to create movement, while the antagonist relaxes and lengthens to facilitate movement.

All or nothing principle

The principle which states that once a nerve impulse reaches a certain threshold, all muscle fibres in that motor unit will contract maximally. if an impulse is below the threshold, no contraction will occur.

Isometric contraction

A type of muscle contraction where the muscle contracts without changing length, generating tension in the muscles.

isoinertial contraction

Where the muscle changes length while responding to a constant load.

Isokinetic contraction

When the speed of movement is constant throughout the entire range of motion.

Slow twitch

Muscle fibres that contract slowly and are resistant to fatigue, helping sustain movements over a long period of time.

Fast twitch fibres (Type II)

Muscle fibres that contract quickly and produce high force, but fatigue rapidly. They are recruited for high-intensity, explosive movements such as sprinting.

Superior

Refers to a body part that is closer to the head than another part.

Inferior

Refers to a body part that is closer to the feet than another part.

Anterior

A body part that is towards the front of the body

Posterior

A body part towards the back of the body

Medial

Towards the midline of the body

Lateral

A body part that moves away from the midline of the body.

Proximal

Refers to a body part that is closer to the trunk.

Distal

A body part that is further away from the trunk.

Superficial

A body part closer to the surface of the body.

Deep

A body part that is internal or further away from the surface of the body.

Palmer

The palm side of the hand.

Plantar

The sole side of the foot.

Median/ Sagittal Plane

Dividing the body into left and right sections.

Horizontal/ transverse plane

Dividing the body into superior and inferior sections.

Frontal/ Coronal plane

Divides the body into anterior and posterior sections.

Fibrous joint

A a fixed or immovable joint where the bones are joined by tough, fibrous connective tissue.

Cartilaginous joint

A slightly moveable joint where the bones are joined by a cartilage, lacking a joint cavity.

Example - Intervertebral discs

Synovial joint

A freely moveable joint where the bones are separated by a synovial cavity between articulating bones.

Pivot joint

A uniaxial synovial joint where a rounded bone fits into a ring of bone and ligament, only allowing for rotation.

Gliding joint

A type of synovial joint where two flat bone surfaces glide against each other.

Ball and socket joint

A multiaxial synovial joint where a rounded bone fits into a cup-like cavity, providing the greatest range of motion.

-allows for flexion/extension, abduction/adduction, rotation, and circumduction

Hinge joint

A uniaxial synovial joint that only allows flexion and extension.

Saddle joint

A type of synovial joint where concave and convex bone surfaces align, allowing movement in two planes.

Condyloid joint

A biaxial synovial joint where an oval-shaped bone fits into an elliptical cavity, allowing for flexion, extension, adduction, and abduction.

Flexion

A joint movement that the decreases angle between two bones.

Extension

a joint movement that increases the angle between two bones.

-Typically occurs in the sagittal plane. (left & right).
For example, straightening the elbow from a bent position.

Abduction

When a body part is taken away from the imaginary midline of the body

Adduction

A joint movement when a part of the body is brought towards the imaginary midline.

Medial rotation

A joint movement when the bone turns on its own axis (rotates) towards the midline of the body.

Lateral rotation

A joint movement when the bone turns on its own axis (rotates) away from the midline of the body.

Circumduction

Refers to circular movement that combines flexion, extension, adduction, and abduction. This allows the limb to move in a cone shape trajectory.

Pronation

A joint movement where the forearm rotates and the palm side faces down.

Supination

A joint movement where the forearm rotates and the palm side faces up.

Dorsiflexion

Refers to a joint movement where the toes point up towards the tibia, decreasing the angle between the foot and the lower leg.

Plantarflexion

A movement at the ankle joint where the toes are pointed downwards, increasing the angle between the foot and the tibia.

Inversion

A joint movement where the sole of the foot is rotated inwards, toward the midline of the body.

Eversion

A joint movement where the sole of the foot is rotated outwards, away from the midline of the body.

Agonist

the muscle primarily responsible for producing the movement.

Antagonist

The muscle that relaxes and lengthens as the agonist contracts.

Stabilisers

A muscle that contracts isometrically to hold a body part steady so the agonist can produce movement.

Fascicles

A bundle of muscle fibres

Pennate muscles

Fibres in a muscle that attach obliquely (at an angle) to a central tendon.

Fusiform muscles

A type of muscle that is spindle-shaped, featuring a thick muscle belly that tapers at both ends, and fibers that run parallel to the tendons.

Muscle fibre

A single muscle cell that contains many myofibrils which contract to produce force.

Motor unit

a group of muscle fibres stimulated by a motor neuron.

Preferential recruitment

When the body recruits specific muscle fibres according to the intensity of the activity. This includes using Type I fibres for low intensity, aerobic endurance activities, and Type II fibres for anaerobic power and explosive movements such as sprinting.

isotonic contraction

A muscle contraction where the muscle length changes under tension. This consists of a concentric phase, where the muscle shortens, and an eccentric phase, where the muscle lengthens while contracting.

Concentric contraction

A type of isotonic contraction where the muscle shortens under tension to overcome and produce movement.

Eccentric contraction

where the muscle lengthens while contracting.

Types of muscles

skeletal, smooth, and cardiac

Types of bones

long bones, short bones, flat bones, irregular bones, and sesamoid bones.

Types of joints

fibrous joints, cartilaginous joints, and synovial joints.

Types of contraction

Include isometric, isotonic (concentric and eccentric), isoinertial, and isokinetic contractions.

Connective tissue

A type of tissue that supports, binds together, and protects parts of the body. These include ligaments and tendons in order to facilitate movement.

Origin

Refers to the attachment point of a muscle that remains stationary during a contraction.

Insertion

The attachment site of a muscle that moves during a contraction.

Convergent muscles

Muscles that have a broad base at the origin and converge to a single attachment site, typically having a triangular shape. Example: deltoid muscle.

Parallel muscles

Muscles where the fibres are arranged in a parallel pattern, running in the same direction as the long axis of the muscle. They can shorten more but produce less force compared to other arrangements.

Unipennate muscle

A type of pennate muscle where the fascicles are located on one side of the tendon. Example: semimembranosus muscle.

Bipennate muscle

A type of pennate muscle where the fascicles insert into the tendon from both sides. Example: rectus femoris muscle.

Multipennate muscle

A type of pennate muscle where the fascicles insert on multiple tendons that taper to a common tendon. Example: deltoid muscle.

Circular muscles

Muscles where the fascicles are arranged concentrically around an opening, decreasing the size of the opening when contracting and increasing it when relaxing. Example: orbicularis oris muscle.