Exam 1: Motor Performance & Points of Reference - Planes & Axes (Wk1)

2 lectures

Motor Performance

Act of executing a motor skill

• Intricate and complex

• Susceptible to fluctuations

• Level of control in all learning

• Learning produces changes in control

EX: typing on a computer, kicking a ball, surfboarding

🧠 Motor Learning

• acquisition and modification of learned movement patterns

• change in motor function that is retained over time

• complex process involving cognitive, perceptual and movement processes

👍 Motor Control

• Outcome of motor learning

• Ability to produce purposeful movement

• Observed and measurable motor activity

Skill

• Goal-directed task

• Multiple processes involved: cognitive, perceptual, motor

Movements

• Behavior characteristics of a specific limb or a combination of limbs

• Not necessarily goal-directed

Motor Skill

• Skill that requires voluntary body &/or limb movement

• Goal-directed responses that consist of body and/or limb movements

• Skills can be simple or complex

• EX: toddler pick up food with a fork, wheelchair basketball 🏀♿

Gross Motor Skill

• Large muscle groups to prod. mvmt (walk, throw, jump)

• Less precision, as target’s far away

• EX: throw football, wheelchair tennis

🖊 Fine Motor Skill

• Small muscles (finger and hand movements), high degree of precision

• Eye-hand coordination

• EX: threading needle, typing on keyboard

Discrete Motor Skill 💡

Skill requiring 1 distinct mvmt, definable beginning & end

EX: turning on lightswitch, kicking soccer ball

Serial Motor Skill 🚗

Putting several discrete movements together in a series or sequence

EX: dribbling a ball up the field and taking a shot at the goal; starting a car

Continuous Motor Skill

Repetitive movements in completing a task

Closed motor skill

• Doing something without an end; predictable

• self-paced, fixed environment

• object waits to be acted upon

• EX: batting cage, practicing golf on your own, walking on campus at 6pm, riding a stationery bike, practicing free throws

Open Motor Skill

• Externally paced, non-stable environment

• Object/context changing

• Finite goal

• EX: walking thru Student Union at lunch, riding bike on city streets, playing in basketball game

Closed Kinematic Chain

• Distal segment of the extremity is fixed or meets with enough resistance to prohibit movement.

• Attempting to produce movement in 1 joint of that extremity will cause predictable movement in other joints of that extremity as well (the “chain” is closed)

• EX: pushups - nowhere for body to go except for moving in relation to ground

Open Kinematic Chain

The ends of the upper or lower extremity are not fixed, thus each joint is free to move without causing motion to occur at other joints in that extremity

• The joints of the extremity are free to function independently or in unison

• EX: throwing anything; object leaves you & goes

Center of Gravity

• As you move, the center of gravity moves

• In anatomical position, located anterior to S2 (second sacral vertebra near pelvis)

Anatomical Position

• Standing upright

• Feet apart, head forward, arms at sides

• Palms FORWARD

• Posterior: back/dorsal

• Anterior: front/volar/ventral

Joint motion is described by?

• Plane(s) in which that motion occurs

• Axis around which the body part rotates

• Motions are described when the body’s in anatomical position, always!

Planes of Motion

• 3 cardinal (principle) planes of the body

• Divide into equal parts

• Lie at right angles to each other

• Pass thru and intersect with each other at the center of gravity

Sagittal Plane (Anterior-Posterior axis)

• Passes through body in anteroposterior direction.

• Divides body into left/right parts

Frontal (Coronal) Plane / Medial-Lateral Axis

• Vertical plane that passes thru laterally (side to side)

• Divides body into anterior & posterior parts

Transverse Plane / Longitudinal or Vertical Axis

• Passes anterior to posterior

• Divides body into superior & inferior parts

Axes of Rotation

• When the body moves, it rotates around an axis

• An axis of rotation is an imaginary line around which movement occurs

• 👉 Each axis is always perpendicular (at a right angle) to the plane of movement

Medial-Lateral Axis (Frontal)

• Direction: Front to back (intersects the frontal plane)

• EX: Elbow flexion/extension

Anterior-Posterior Axis (Sagittal)

• Direction: Side to side (intersects the sagittal plane)

• EX: Shoulder abduction/Adduction; wrist radial/ulnar deviation

Vertical (Longitudinal) Axis

• Direction: vertically proximal to distal (intersects the transverse plane)

• EX: Shoulder internal/external rotation

Sagittal Plane/Frontal (Antero-Posterior) Axis

• Mostly flexion/extension mvmts

• Flexion: angle between two adjacent bones decrease as the movement progresses (bending elbow)

• Extension: angle between two adjacent bones increases, return from flexion (straighten elbow)

• Hyperextension: the continuation of extension beyond the straight line

Frontal (Coronal) Plane/Sagittal Axis

• Abduction - sideward movement away from the midline of the body or body part

• Adduction - sideward movement toward the midline of the body or body part, return from abduction

• Ulnar Deviation (add) - hand moves in direction of the little finger at the wrist (toward body)

• Radial Deviation (abd) - hand moves in direction of the thumb at the wrist (in anatomical position)

Transverse Plane/Vertical (Longitudinal) Axis

• Mostly rotational mvmts

• Outward (lateral, external) rotation: rotation of a whole body part in such a way the anterior aspect of the segment turns laterally (occurring at shoulder and hip)

• Inward (medial, internal) Rotation: rotation of a body part; the anterior aspect of the segment turns (twist torso = spinal rotation)

• Neck & trunk rotation (turn head to look over shoulder)

• Forearm supination/pronation (rotate up/outward; rotate down/inward)

Combined Planes/Axes

• Combo of all diff motions occurring @ that joint

• Not really measurable; just fxnal mvmts we have pts do

• DON’T need to identify this

Combined Planes/Axes: Circumduction

combination of the movements, flexion, extension, abduction, adduction performed in sequence, so the segment traces out a conical shape in space

Combined Planes/Axes: Horizontal Adduction

upper extremity, first raised to shoulder level, is moved through the transverse plane toward the midline of the

• EX: in anatomical position, moving your arm inward so hand moves across your other shoulder

Combined Planes/Axes: Horizontal Abduction

upper extremity, first raised to shoulder level, is moved through the transverse plane away from the midline of the body

• EX: in anatomical position, moving your arm outward medial straight

Combined Planes/Axes: Diagonal Adduction

movement by limb through a diagonal plane toward and across the midline of the body

• EX: pulling stretchy rubber down diagonally towards your left hip

Combined Planes/Axes: Diagonal Abduction

movement by limb through a diagonal plane across and away from the midline of the body

• EX: pulling a stretchy rubber up and outwards above your head diagonally

Degrees of Freedom (DOF)

• Describes how many different ways a joint can move.

• A joint can have up to 3 degrees of angular freedom; more degrees = more dynamic mvmt

• Number of permitted planes of angular

1 DOF

• mvmt in 1 direction; uniaxial joints

• ONLY move in extension/flexion

• knee, elbow, finger tip, interphalangeal joints

2 DOF

• mvmt in 2 directions; biaxial joints

• wrist: extension/flexion, side to side

• Metacarpophalangeal (MCP) finger joints

3 DOF

• mvmt in 3 directions; triaxial joints

• shoulder and hip joints

Kinetics

The study of the effect of forces on the body

Force

• push or pull acting on matter

• forces acting upon objects/us:

  • external: gravity, friction, resistance

  • internal: muscle contraction & various loads (compression, tensile)

Compressive Force

Translatory force applied in such a manner that one joint segment is pressed toward the other joint segment

EX: leaning arms onto a table, starting position for push ups, standing

Distractive Force (tensile, traction)

Translatory force applied in such a manner that one joint segment is pulled away from the other joint segment

EX: hanging from a bar, tug-o-war, etc.

Shear Force

Forces that are applied parallel to contacting body surfaces that may cause shear stress on the materials and structures on which they act – forces that act in opposite directions (sliding)

Ex: Sliding into base, crutches against floor surface

Torsion

• Force that causes the body or body part to twist around its own longitudinal axis

• Affects soft tissue more than bony structures

• EX: twisting your body to stretch

Combined load

• combination of forces may occur: torsion + compression, bending with torsion

• EX: when you jump off a surface and twist your ankle when you land; weakest link goes out first (ligament that absorbed most load)

Effect of Forces on an object or the body are dependent on:

• magnitude of the force

• direction from which the force is acting (vertical, horizontal, oblique)

• point of contact with the object (center, off center)

• whether or not the force is acting on a freely moving or fixed object