KPE160 Midterm

Anatomical Position

spine in neutral position, eyes straight forwards, arms and forearms at side with elbows extended and hands supinated, feet together with knees and hip straight, penis erect

Sagittal Spinal Curves

Lordosis and kyphosis

Frontal Spinal Curve

scoliosis

Transverse Spinal Curve

rotoscoliosis

Base of Support

the area circumscribed by the outermost parts of your contact patch

Contact Patch

the portion of the body that is in contact with the earth's surface

Contact Pressure

the weight/area for each space within the contact patch

Centre of Pressure

the point on the ground where the resultant pressure vector falls

Assessing Posture in the Sagittal Plane

pelvic tilt, spinal curves and abnormalities

Assessing Posture in the Coronal Plane

spinal curves, left-right asymmetries, extremity valgus/varus

Assessing Posture in the Transverse Plane

lower extremities external/internal/pronation/supination, trunk directions, scapular angle

Newton's First Law

a body will remain at constant momentum unless acted upon by an unbalanced external force

Newton's Third Law

every action has an equal and opposite reaction

Articular Surfaces

the points of separation between bones needed to allow easy movement with low friction

Joining structures

ligaments, tendons, muscles, fibrocartilage

Degrees of Freedom of Joint Movement

6 components of 3D space: x, y, z, xy, xz, yz

Physiologic Motion

joint movement in a natural DoF during movement caused by normal muscle activation and normal reaction forces

Non-Physiologic Motion

primarily independent movement in a DoF that does not occur naturally under normal loading

Accessory Motion

a small amount of non-physiological motion that normally accompanies physiological motion

Ginglymus Joint

one RDoF orthogonal to axis. Eg. knee, finger joints

Condyloid Joint

two RDoFs orthogonal to axis. eg. wrist

Trychoid JOint

one RDoF to axis. eg. radius and ulna

Enarthrosis Joint

three RDoFs to axis. eg. shoulder

Arthrodial Joint

one to three TDoFs. eg. carpels

Condyloid Joint Movement

flexion-extension, abduction-adduction

Ginglymus Joint Movement

flexion-extension

Trychoid Joint Movement

pronation-supination

Enarthrodial Joint Movement

floating axis system

Scapular Movements

elevation, tipping, protraction, retraction, shrug

Spinal Movements

flexion-extension, left-right rotation, left-right lateral bend

Foot and Ankle Movements

dorsi-plantar flexion pronation-supination

Range of Motion

the extent of joint movement in a physiological degree of freedom of motion

Hypermobility/flexibility

Greater than normal RoM

Hypomotibility/restriction

less than normal RoM

Active RoM

how far someone can move a joint using only the muscles that span that joint

Passive RoM

how far a joint can be moved by application of external forces

Flexibility

ability of muscles and soft tissues to lengthen

Mobility

affected by joint RoM, flexibility, strength, motor control, past experiences, and motivation

Assessing Active RoM

ask the client to move the target joint as far as they are comfortable doing so with their own muscles

Assessing Passive RoM

move the target joint until significant stiffening is felt, or the subject reaches their tolerance

Constraints of Joint Motion

passive structures (bones, cartilage, ligaments), active structures (muscles, fascia)

Laxity

greater than normal joint play or non-physiologic motion

Statistical Flexibility

a joint that displays above average RoM in that DoF

Generalized Hypermobility

tested by the Beighton score

Adequate Task Flexibility

RoM sufficient to perform target tasks

Uniped Segment

foot, leg, thigh, HAT

Uniped Joints

ankle, knee, hip

Uniped Muscle Groups

dorsi-plantar flexors, hip flex-extendors, knee flex-extendors, rectus femoris, hamstring, gastroc

Multiarticular Structures

structures that span more than one skeletal articulation

Passive Sufficiency

sufficient length of structures such that they do not constrain passive motion of any joints via tension

Test for Bi-Articular Passive Sufficiency

compare PRoM of one articulation spanned by the muscle in flexed and relaxed positions

Mechanics of Deformation

forces applied to material bodies cause acceleration and deformation

Mechanics of Deformation Players

elasticity, failure, plasticity, viscosity

Plastic Deformation

deformation that remains after the load is removed

Elastic Deformation

tendency of a material body to return to its original shape after deformation by a load

Human Connective Tissue Mechanics of Deformation

tendons/ligaments rupture at 110% strain, inactivated muscles fail at 200% strain

Creep

if a visco-elastic body is stretched by a constant load, its length will increase slowly along a first-order curve

Load Relaxation

tension decreases along a first-order curve if a visco-elastic body is stretched by a constant load

Temporal Load Profile

the magnitude of load at each point in time

Mechanical Effects of Stretching

short-term increase in length, short-term decrease in force production

How to Stretch

after activity or at other times, multi-articular structures, protect compliant segments

Moment Arm

the perpendicular distance from the line of action of a force to a point or axis of rotation

Muscle-Tendon Units

organs that join articulated segments of our body. control posture and movement

Muscle Structure

bundled myofibrils of actin and myosin.

Excitability of Muscle

an electrical potential is maintained by ionic gradients and stimulated by neurons. the neuron depolarizes and releases acetylcholine at a neuro-muscular junction, which causes depolarization of the muscle fibres

Motor Unit

a single motor neuron and the muscle fibres attached to it

Sarcomere

overlapping filaments of actin and myosin attached by cross-bridges

Factors Affecting Muscle Force Production

activation, architecture, cross-sectional area, length, velocity

Measuring Muscle Activation

measuring with EMG, maximum EMV = MVA. muscle activation is expressed as %MVA

Muscle Architecture

fibres within muscles are attached to tendons or bones in different arrangements and angles of pennation

Anatomical Cross-Sectional Area

plane orthogonal to line of action

Physiological Cross-Sectional Area

plane orthogonal to the line fibres

Sarcomere Length vs Tension

the maximum force is at mid-length when the filament overlap is optimal

Active Tension

strongest at the middle range of motion, comes from actin and myosin

Passive Tension

gains strength after the middle range of motion, comes from fascial envelope

Kinetic Chains

a series of linked segments that can change shape by flexing or extending

Closed Kinetic Chain

the distal segment is fixed and proximal segment moves

Open Kinetic Chain

the distal segment is free to move

Muscle Moment Arm

determined by the location of the line of action of the muscle, and the location of the axis of rotation of the joint

Functions of Muscle Activation

accelerating, maintaining constant velocity, decelerating

Isotonic Muscle Activation

activation with constant tension. can be concentric/isometric/eccentric, may be isokinetic

Concentric Muscle Activation

positive shortening velocity. can accelerate, maintain velocity, and stabilize deceleration

Eccentric Muscle Activation

negative shortening velocity. can decelerate, maintain velocity, and stabilize acceleration

Isometric Muscle Activation

zero shortening velocity, muscle length is constant. can only stabilize segments

Agonist

concentric

Antagonict

eccentric

Bi-Articular Muscles in the Sagittal Plane

during simultaneous flexion-extension at both joints, the muscle is isotonic.

Flexion of Gravity in the Sagittal Plane

gravity generates flexion moments that increase with joint flexion

Support Moment

the sum of all moments of muscle forces that counterract the moments of force of gravity

Moments of Gravity in the Coronal Plane

double stance moments cancel-out left to right with no muscular activation. single stance moments have no cancellation and require muscle activation

Coronal Plane Moments of Gravity at the Rearfoot in Single Stance

the joint sways between valgus, neutral, and varus. the hip is adducted

Axial Rotation of the Hip and Rearfoot Linked by the Knee

the chain is driven axially from either end — hip or rearfoot. hip muscles are bigger and produce a greater force

Rearfoot Linkage of Axial and Coronal Rotation

subtalar joint links 3RDoF. pronation and supination occurs

Rearfoot Pronation Moment of Gravity

navicular drop caused by gravity's moment lowers the body's CoM by 1-2cm

Sagittal Plane Variations in Squatting

centre of pressure, mobility, counterbalance

Statistical Mechanical Equilibrium

positional equilibrium, which is zero acceleration, zero velocity, and constant position

Dynamic Mechanical Equilibrium

zero net force with movement

Equilibrium Sway

equilibrium may tend towards a constant value, but vary around it with different frequency and magnitude

Stability of Equilibrium

ability to withstand change or perturbation

Types of Human Mechanical Equilibria

joint equilibrium and postural equilibrium