OCTH 222: Kinesiology Joints and Planes

What is a motor performance?

The act of executing a motor skill

• Intricate and complex

• Susceptible to fluctuations

• Level of control in all learning

• Learning produces changes in control

What is motor learning?

The acquisition and modification of learned movement patterns, the change in motor function that is retained over time.

Complex process involving cognitive, perceptual, and movement processes

What is motor control?

The outcome of motor learning → the ability to produce purposeful movement; the observed and measurable motor activity

What is a skill?

Goal directed task (simple or complex)

Involves multiple processes (cognitive, perceptual, motor)

What is a movement?

Behavior characteristics of a specific limb or a combination of limbs

Not necessarily goal directed

What is an open kinetic chain?

The distal segment of the moving extremity is NOT fixed

ex. Throwing a baseball or holding a jar out in space

What is a closed kinetic chain?

The distal end of the moving extremity is FIXED

ex. Standing up by pushing off of a chair

What is a gross motor skill?

Uses large muscle groups to produce movement (walk, throw, jump)

Less precision

ex. playing wheelchair tennis

What is a fine motor skill?

Uses small muscles (finger and hand movements), high degree of precision

Eye-hand coordination

Ex. threading a needle

What is a discrete motor skill?

A distinct movement with a definable beginning and end

ex. flicking a switch, shooting a goal

What is a serial motor skill?

Several discrete movements together in a series or sequence

ex. starting a car, dribbling a ball and then shooting it into a basket

What is a continuous motor skill?

Movements that are repetitive in completing a task

ex. Riding a bicycle, jogging

What is a closed motor skill?

Start/pace can be controlled

Fixed environment or target

ex. typing

What is an open motor skill?

Pace/movement cannot be controlled

Dynamic/non-stable environment

Object or context is changing

ex. playing hockey with other people

What is kinetics?

The study of the effect of forces on the body

What is a force?

push or pull of matter

What are external forces that act upon us/objects?

Forces acting from OUTSIDE the body:

Gravity

Friction

Resistive forces (resistance from weight of object being carried)

What are internal forces that act upon us/objects?

Forces generated WITHIN the body:

Tensile forces (pulling)

Compressive forces (pushing)

Exerted force (effort generated from muscles to overcome resistnace)

What are the different types of load/force on the body?

1. Compressive force (push)

   1. Leaning arms onto a table, starting position for push ups, standing

2. Distractive force (pull)

   1. Hanging from a bar, tug-o-war

3. Shear force (slide)

   1. Sliding into base, crutches against floor service

4. Bending force

   1. Compressed or tensioned on one side

5. Torsion force (twist)

   1. Twisting the body around

6. Combined loading

   1. Jumping off a table and twisting your ankle as you land

How can healthy/weakened tissues resist changes in structure/shape?

Healthy tissues can partially resist changes in their structure and shape

Tissue weakened by disease, trauma, or prolonged disuse may not be able to resist these forces

What is Young’s Modulus?

Graph of how much a tissue strains under increased stress (force)

What are the different parts of Young’s Modulus?

1. Elastic Range

   1. Forces related to functional activities occur within this safe range

   2. Tissue able to return to its original shape

2. Yield Point

   1. Maximal stress before tissue failure

3. Plastic Range

   1. Permanent deformation depending on a tissue’s stiffness

      1. Bone: fracture

      2. Ligament/tendon: stretch → rupture

What is the clinical relevance of the stress-strain curve?

Careful stretching within the plastic range can lead to increased range of motion (principles we apply to passive stretching)

The soft tissue can assume new and greater length after the stretch force has been removed

Remodeling of plastic changes take 6 weeks to 6 months, consistent stretching is important

Exceeding the plastic range of connective tissue can lead to:

• Tearing and ruptures of tendons and ligaments

• Avulsions - forceful tearing away of a part or structure

• Fractures

What is muscle torque (moment)?

A muscle’s ability to rotate a joint

Ex. biceps exert a moment to rotate the forearm around the elbow

More force or more distance = more torque

What is the moment arm (lever arm)?

Shortest distance from joint axis to line of force

The same object can feel easier or harder depending on how far it is from the joint

What are the three parts of a lever?

1. Load

• Body part/object/gravity

2. Fulcrum

• Joint

3. Effort

• Muscle pull

What is a first-class lever?

Exerted force and resistive force on opposite sides of an axis like a seesaw (fulcrum is in the middle)

Best for balance

Ex. neck extension and flexion

What is a second class lever?

Resistive force (load) is closer to the axis than the exerted force like a wheelbarrow

ex. Ankle

Powerful but limited

What is a third class lever?

Opposite of second-class lever: The exerted force is closer to the axis than resistive force like a shovel

Most muscles in the body use this patter: Muscle force is close to the joint

Good speed and range but more muscle effort

Ex. biceps (fulcrum = elbow, load is in the hand)

What is joint motion described by?

The plane(s) in which that motion occurs

The axis around which the body part rotates

***Described when the body is in anatomical position always***

What is anatomical position?

Standing upright

Feet apart

Head forward

Arms at sides

Palms forward

What is another way to describe posterior?

Back/Dorsal

What is another way to describe anterior?

Front/Volar/Ventral

What does proximal describe?

Location that is coser to trunk of body

What does distal describe?

Location that is away from the trunk of body

What does medial describe?

Location that is closer to midline of body

What does lateral describe?

Location that is away from midline of the body

What does radial describe?

Location of something that is closer to the radius (thumb side) in the forearm, wrist, and hand

What does ulnar describe?

Location of something that is closer to the ulna (pinky side) in the forearm, wrist, and hand

What are the planes of motion?

Three cardinal (principle) planes of the body

Divide into equal parts

Lie at right angles to each other

Pass through and intersect with each other at the center of gravity

What are the axes of rotation?

When the body moves, it rotates around an axis

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

What is the Medial-Lateral (Frontal) axis?

Direction: Front to back (movement in the sagittal plane)

ex. elbow flexion/extension

What is the Anterior-Posterior (Sagittal) axis?

Direction: Side to side (Movement in the frontal plane)

ex. Shoulder abduction/adduction; wrist radial/ulnar deviation

What is the Vertical (Longitudinal) axis?

Direction: Vertically proximal to distal (movement in transverse plane)

ex. Shoulder internal/external rotation

What motions occur in the sagittal plane/frontal axis?

Flexion: Angle between two adjacent bones decrease as the movement progresses

Extension: Angle between two adjacent bone increases, return from flexion

Hyperextension: The continuation of extension beyond the straight line

What motions occur in the frontal 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 (adduction): Hand moves in direction of the little finger at the wrist

Radial deviation (abduction): Hand moves in direction of the thumb at the wrist

What motions occur in the transverse plane/vertical axis?

Outward (lateral, external) rotation: Rotation of a body part where the anterior aspect of the segment turns laterally (occurring at shoulder and hip)

Inward (medial, lateral) rotation: Rotation of a body part where the anterior aspect of the segment turns

ex. Neck and trunk rotation; forearm supination/pronation

What movements occur within combined planes/axes?

Circumduction

Horizontal adduction

Horizontal abduction

Diagonal adduction

Diagonal abduction

What is circumduction?

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

ex. rotating arm in a circle

What is horizontal adduction?

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

What is horizontal abduction?

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

What is diagonal adduction?

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

What is diagonal abduction?

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

What do degrees of freedom (DOF) describe? Up to how many DOF can a joint have?

How many ways a joint can move (Number of permitted planes of angular motion)

Up to three degrees of angular freedom

More DOF = more movement options = more control needed

What does 1 degree of freedom allow for? Examples?

Movement in one direction

ex. Elbow, knee, finger interphalangeal joints

What does 2 degrees of freedom allow for? Examples?

Movement in two directions
ex. Wrist, hand metacarpophalangeal joints

What do 3 degrees of freedom allow for? Examples?

Movement in three directions

ex. Shoulder

What is a joint?

The junction of pivot point between two or more bones. Movement of the body occurs primarily through rotation of bones about individual joints. Joints can also transfer and dissipate forces produced by gravity and muscle activation

• Articulation between two structures

• Can be bone to bone, and bone to cartilage

• Have both a stability and mobility role

What in a synarthrosis (fibrous) joint?

Immovable

Classification: Synarthrosis
Movement allowed: None
Main purpose: Stability/protection

Ex. Skull sutures

What is an amphiarthrosis (Cartilaginous) joint?

Slightly moveable joint

Classification: Amphiarthrosis

Movement allowed: Slight

Main purpose: Support + Flexibility

Ex. Spine

What is a diarthrosis (Synovial) joint?

Highly moveable joint

Classification: Diarthrosis

Movement allowed: Free

Main purpose: Movement

Ex. Shoulder

What are kinds of synarthrosis “immovable” (mostly) joints?

1. Suture (Synistosis) sutures of the skull

2. Gomphosis - peg in a hole - (ex. teeth)

3. Syndesmosis - tough fibrous connection between bones - (ex. interosseous membrane, tight ligament between tibia/fibula)

What are examples of amphiarthrosis - slightly moveable - joints?

1. Fibrocartilage

   1. Very strong

   2. Less flexible than hyaline cartilage

   3. Excellent at resisting compression and tension

   4. Symphysis - fibrocartilage connection

2. Hyaline cartilage

   1. Smooth

   2. Slightly flexible

   3. Provides cushioning

   4. Helps to absorb shock

   5. Synchondrosis - hyaline cartilage connection

What are diarthrosis (syovial) joints?

1. Freely moveable

2. Articulating surfaces covered in hyaline cartilage

3. Enclosed in a joint capsule

4. Synovial fluid-filled cavity

What is a fibrous capsule (stratum fibrosum)?

Within the joint capsule of synovial joint

Outer layer, fibrous, poorly vascularized, richly innervated

What is the synovial membrane (stratum synovium)?

Within the joint capsule of synovial joints
Inner layer, highly vascularized, poorly innervated, produces synovial fluid

What is the primary angular motion of a hinge joint? Examples?

Motion around a single axis, Flexion and Extension only

Analogy: Door Hinge

Ex. Humero-ulnar joint (elbow), (distal and proximal) interphalangeal joints

What is the primary angular motion of a pivot joint? Examples?

Motion around one axis (vertical), bones rotating around another

Spinning of one member around a single axis of rotation

Analogy: Doorknob

Ex. Priximal radioulnar, Humeroradial joint, Atlanto-axial joint

What is the primary angular motion of a Condyloid (Ellipsoid) joint? Examples?

Movement around two axes

Biplanar motion (flexion-extension and abduction-adduction) circumduction
Analogy: Flattened convex ellipsoid paired with a concave trough
Ex. metacarpal phalangeal (wrist) joint, Radiocarpal joint

What is the primary angular motion of a ball-and-socket joint? Examples?

Movement in all three planes/axes

Triplanar motion (flexion-extension, abduction-adduction, and internal-external rotation)
Analogy: Spheric convex surface paired with a concave cup
Ex. Glenohumeral joint (shoulder), Coxofemoral (hip) joint

What is the primary angular motion of a plane/gliding joint? Examples?

Movement (sliding/gliding) in all three planes/axes

Typical motions include slide (translation) or combined slide and rotation
Analogy: Relatively flat surfaces apposing each other, like a book on a table

Ex. Carpometacarpal joints (digits II to IV), intercarpal joints, intertarsal joints, sternoclavicular, acromioclavicular

What is the primary angular motion of a saddle joint? Examples?

Modified condyloid, movement around two planes/axes

Flexion, extension, abduction, adduction, circumduction, opposition

Biplanar motion; spin between bones is possible but may be limited by interlocking nature of joint

Analogy: Each member has a reciprocally curved concave and convex surface oriented at right angles to the other, like a horse rider and a saddle

Ex. Carpometacarpal joint of the thumb, sternoclavicular joint

What is the primary angular motion of a condyloid joint? Examples?

Biplanar motion; flexion-extension and abduction-adduction, or flexion-extension and axial rotation (internal-external rotation)

Analogy: Mostly spheric convex surface that is enlarged in one dimension like a knuckle; paired with a shallow concave cup

Ex. Metacarpohalangeal joint, tibiofemoral (knee) joint

What is arthrokinematics?

Motion between articular surfaces of joints

What are the three fundamental movements in curved joint surfaces?

Roll, slide, and spin

What is the movement for convex-concave surfaces?

The convex member rolls and slides in OPPOSITE directions

What is the movement for concave-on-convex surfaces?

The concave member rolls and slides in SIMILAR directions

What is close-pack position?

When the position of the bony components of the joint match each other as closely as possible. There is maximum area surface contact

The ligaments and capsule of the joint become taut

The joint is mechanically compressed and cannot be easily passively distracted. Minimal accessory movements. Joint alignment is more stable

The components of the joint are “congruent”

What is loose-pack position?

All positions other than a joint’s close-packed position

The surfaces of the bony components of the joint are not aligned to fit perfectly

The ligamentous and capsular surfaces are slack

The components of the joint are NOT congruent

Clinically: Refers to the maximally loose-pack position

Also the joint resting position

What factors affect joint stability?

1. Osseous support

   1. More surface contact = more stability

2. Ligamentous support

   1. Joint capsule surrounds and holds the joint together

   2. Ligaments limit excessive motion

3. Muscular support

   1. Muscles crossing a joint provide dynamic support

   2. Muscle tone and strength help maintain alignment

What is goniometry?

The measurement of joint range of motion (ROM) using a goniometer

What do occupational therapists use goniometry for?

1. Measure movement limitations

2. Track progress over time

3. Document outcomes

4. Guide intervention planning

What is active range of motion (AROM) ? What does it tell us?

The amount of movement a person can perform using their own muscles, without help

Can tell us:

1. Muscle strength

2. Motor control

3. Willingness to move

4. Functional movement ability

What is passive range of motion (PROM) ? What can it tell us?

The amount of movement possible when someone else moves the joint (therapist or caregiver), and the client stays relaxed

Can tell us:

1. Joint flexibility

2. Capsule and ligament tightness

3. Pain or stiffness

4. Structural limitations

What do you feel at the end of PROM? What does it help us understand?

End feel is the feeling/sensation experienced by an examiner as a barrier or resistance to further motion when passively moving the joint of the client

It helps OTs understand what structure is limiting motion

What is an abnormal joint end feel?

Empty: No real end feel because pain prevents reaching the end of ROM; no resistance felt

When is an abnormal joint end feel a cause for concern?

When it is not the expected end feel for that particular joint

Soft: soft tissue edema, synovitis

Firm capsular: leathery; scar tissue, tissue shortening

Bony/hard: osteoarthritis, fracture

What skeletal conditions affect the musculoskeletal structures?

Ehlers-Danlos Syndrome

Marfan Syndrome

What is Ehlers-Danlos Syndrome?

Group of genetic connective tissue disorders causing abnormal collagen synthesis, increasing skin elasticity and joint mobility

1. Incidence ~1 in 5,000 cases

2. Often develops in childhood but undiagnosed until later in life

3. Thirteen EDS subtypes have already been identified, with 19 known causal genes involved in extracellular matrix and collagen development

Joint hypermobility or laxity - hallmark characteristic of hypermobile EDS

Skin can be stretched very far, can fully touch the ground when bending over with legs straight, can bend finger to 90 degree angle when hand is flat on table)

What is Marfan Syndrome?

Autosomal dominant connective tissue disease that commonly cause aortic dissection and regurgitation in addition to musculoskeletal system abnormalities

Increased join laxity, excessive long bone growth, scoliosis, and sternal deformities such as pectus excavatum are common

(Can still see most of thumb when fold under four fingers of hand, can fully touch thumb to pinky when circle wrist with fingers)