Structural Kinesiology Exam 1

Structural Kinesiology

Study of muscles, bones, and joints as they are involved in the science of movement (how these structural vary in size shape, and location determines their function)

600+ muscles

206 bones

Anatomical Position

Standing in an upright posture, facing straight ahead, feet parallel and close, palms facing forward (all questions regarding plane should be done in this position) 

Fundamental Position - same but with arms at the side and palms facing body

Sagittal Plane

Flexion/ Extension

Frontal Axis

Ankle Plantarflexion and dorsiflexion

Flexion

Bending movement that results in a decrease of angle in joint

Extension

Straightening movement that results in an increase of angle in a joint

Frontal Plane

Abduction/Adduction

Sagittal Axis

Scapular movements - elevation, depression, protraction, retraction, downward rotation, trunk flexion, ankle inversion/eversion

Abduction

Lateral movement away from midline of trunk in frontal plane

Adducation

Movement medially toward midline of trunk in lateral plane

Transverse Plane

Internal/External Rotation

Longitudinal Axis

Wrist pronation/supination, horizontal shoulder abduction/adduction, transverse pelvic rotation

Internal Rotation

Rotary movement around longitudinal axis of bone toward midline of body (medial rotation)

External Rotation

Rotary movement around longitudinal axis of a bone away from midline of body (lateral rotation)

Diagonal/Oblique Plane

Most movements in daily life in a combo of planes

Combination of sagittal, frontal, transverse plane

Any combination of movements

• Diagonal Abduction/Adduction

• Circumduction

Diagonal Abduction

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

Diagonal Adduction

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

Circumduction

Circular movement of a limb that delineates an arc or describes a cone

When shoulder joint and hip joint move in a circular fashion around a fixed point

Combination of flexion/extension, abduction/adduction

Axes of Rotation

90 deg. angle to the plane

Sagittal Plane - Frontal Axis (flexion/extension)

Frontal Plane - Sagittal Axis (Abduction/adduction)

Transverse Plane - Longitudinal Axis (internal/external rotation)

Diagonal Plane - Diagonal Axis

Anatomical Terminology

Anterior/Posterior

Superior/Inferior

Deep/Superficial

Proximal/Distal

Lateral/Medial

Dorsal/Ventral

Plantar/Palmar

Bilateral

Contralateral - same side of the body

Ipsilateral - opposite side of body

Skeletal System

206 bones

Axial Skeleton - 80 bones

Appendicular Skeleton - 126 bones

Axial Skeleton

Skull, vertebral column, ribs, sternum

Appendicular Skeleton

Extremities and the pelvic and shoulder girdles

5 Main function of Bone

1. Protection of vital soft tissues

2. Support to maintain posture

3. Movement; points of attachment for muscles and acting as levers

4. Mineral storage such as calcium and phosphorus

5. Hematopoiesis which occurs in vertebral bodies, femur, humerus, ribs, sternum

• Process of blood cell formation in the red bone marrow

Osteoblasts

Primary function is new bone formation - build bone

Osteoclasts

Primary function is bone restoration - breakdown/absorb bone

important in the development, growth, maintenance, repair of bone

Bone Composition

60-70% of bone weight is made of mineral

• Ca, P, Na - Give bone its strength

20-30% of bone weight is water

Collagen / ground substance - Give bone its flexibility

Cortical / Compact Bone

5-30% Porous

Stiff/Dense

Provides protection and support

Can withstand greater stress

Cancellous / Trabecular Bone

30-90% Porous

Spongy/Permeable

Makes up most of bone tissue epiphysis of long bones, and the other majority of other bone types

More elastic/flexible than cortical bone

Bone Properties

Bone is living tissue and is active though life

Remodeling (ongoing replacement of old bone with new bone) occurs continuously

Bone size and shape are due to the stresses applied to them

Wolff’s Law

Bone is laid down where needed and resorbed where not needed

• Bone becomes stronger/thicker with stress

• When loading is decreased, bone weakens

Add bone to where there is stress and leaves w/ absent stress

Osgood Slaughter - Extra bone under patella

Bone Types

Size, Shape, Location of bone - Determine its function

1. Long Bones

2. Short Bones

3. Flat Bones

4. Sesamoid Bones

5. Irregular Bones

Long Bones

Long cylindrical shaft with relatively wide, protruding ends

Shaft contains the medullary canal

Ex: Phalanges, metatarsals, metacarpals, tibia, fibula, fumur, radius, ulna, humerus

Diaphysis

Long cylindrical shaft - main portion

Epiphysis

Ends of long bone

Made of cancellous bone

Epiphyseal Plate

Referred to as growth plate

Thin plane of cartilage

Plates close with maturity, time varies

Long bone Xray

Short Bones

Small, cubed-shaped, solid bones

Proportionally large articular surface to articular with more than one bone

EX: carpals, tarsals, talus (base of hands/foot)

Flat Bones

Usually have a curved surface, vary from thick (where tendons attach) to thin

EX: ilium, ribs, sternum, clavicle, scapula

Sesamoid Bones

Embedded within tendons, Improve mechanical advantage of joint

Improve mechanical advantage of movement

Within patellar tendon and flexor tendon in 1st metatarsophalangeal joint (knee cap and big toe)

Irregular Bones

Variety of shapes and sizes for variety of purposes

Include bones throughout the entire spine, ischium, pubis, maxilla

Articular Cartilage

Thin layer of hyaline cartilage covering articular surface of bone

• Cushions - absorbs compressive forces

• Reduces friction on underlying bone

Periosteum

Membrane around surface of bone not covered by articular cartilage

Important for bone growth, repair, nutrition

Point of attachment for ligament and tendons

Bony Landmarks can Indicate. . .

• Muscular attachment

• Joint Function

• Space for soft tissue

Processes

Elevations and Projections

Process that form joints:

Condyle, Facet, Head

Processes to which ligaments, muscles or tendons attach:

Crest, Epicondyle, Line, Process, Spine (spinous process), Suture, Trochanter, Tubercle, Tuberosity

Cavities

Depressions - Opening and Groves

Facet, Foramen, Fossa, Fovea, Metus, Sinus, Sulcus

Articulation

Connection of bones at a joint usually to allow movement between surfaces of bone

• Freedom or range of motion is limited by ligaments and muscles

Articulations may be classified according to the structure and function of joints

Classification of Joints

Classification Categories by Structure

Fibrous —> Cartilaginous —> Synovial (Most Movement)

Classification Categories by Function

Synarthrodial —> Amphiarthrodial —> Diarthrodial (Most Movement)

Synarthrodial Joints

Immovable Joints

2 Groups

• Suture - Cranial bones

• Gomphosis - Sockets of teeth

Amphiarthrodial Joints

Slightly Moveable Joints

Syndesmosis

• Held by strong ligaments

• EX: inferior tib/fib

Symphysis

• Separated by fibrocartilage

• EX: Symphysis Pubis

Synchondrosis (Most Movement)

• Separated by hyaline cartilage '

• EX: Costochondral Joints

Diarthrodial Joints

Freely Movable

Synovial Joints

• Composed of a sleeve-like joint capsule

• Secretes synovial fluid to lubricate the joint cavity (area w/ in cavity)

Ligaments (result from thicker areas of joint capsule)

• Bone to bone

• Provide static stability to joints

Intraarticular Ligaments - Within the joint capsule (ACL)

Extraarticular Ligaments - Outside of the joint capsule (LCL)

Fibrocartilage Discs - Some have, used for additional cushioning and stability

• EX: glenohumeral Labrum, Meniscus of knee

6 Types of Diarthrodial Joints

Arthrodial - Gliding joint

Condyloid - Biaxial ball and socket, ovoid, ellipsoidal

Enarthrodial - Multiaxial ball and socket

Ginglymus - Hinge joint

Sellar - Saddle joint

Trochoid - Pivot, screw joint

Arthrodial (gliding) Joint

2 plane or flat bony surfaces which butt against each other

little motion possible in 1 joint articulation

Permits limited gliding

EX: Vertebral Column, Carpal Bones on Hand

Motions - Flexion/Extension, Abduction/Adduction, Internal/External Rotation, Circumduction

Condyloid (Ellipsoidal) Joint

Biaxial ball and socket joint

2 axes and 2 planes

one bone with oval concave surface received by another bone with an oval convex surface

EX: 2-5 metacarpophalangeal or knuckle joints, Base of Hand into wrist

Motions - Flexion/Extension, Abduction/Adduction, Circumduction

Enarthrodial (ball and socket) Joint

Multiaxial / triaxial ball and socket joint

Bony rounded had fitting into a concave articular surface

Ex: Hip and GH shoulder Joint

Motion - All movements

Ginglymus (hinge) Joint

Uniaxial Articulation

Articular surfaces allow motion in only one plane

EX: Elbow, Knee, Ankle

Motions - Flexion / Extension

Trochoid (Pivot) Joint

Uniaxial Articulation

Articualr surafces allow motion in only one plane

EX: Atlantoaxial joint - odontoid, which turns in a bony ring, proximal and distal radioulnar joints (Atlas/Axis, radioulnar joint)

Motions - Internal and External Rotation

Sellar (saddle) Joint

Unique multiaxial / Triaxial joint

2 reciprocally concave and convex articular surfaces

EX: 1st carpometacarpal joint at the thumb, sternoclavicular joint

Motions - Flexion/Extension, Abduction/Adduction, Internal/External Rotation, Circumduction

Range of Motion

Area through which a joint may normally be freely and painlessly moved

Normal ROM varies

Measured with a goniometer

Skeletal Muscles

600+ skeletal muscles compose 40-50% of body weight

215 pairs of skeletal muscles usually work together to produce actions at the joints that they cross

Purpose of Skeletal Muscles

Responsible for movement of body at all joints - muscle contraction produces forces that cause joint movement

Provide:

• Protection

• Posture and support

• produce a major portion of total body heat (shivering thermogenesis)

Motor Neurons

Transmit impulses from CNS to muscles

Sensory Neurons

Transmit impulses from body to CNS

Motor Unit

Motor Neuron + Muscle it innervates

Innervation

Refers to the nerves responsible for stimulating muscle fibers

Muscle may be innervated by one or more nerves and one nerve mau innervate several muscle groups

Proprioception

Subconscious mechanism by which the body regulates posture and movement

• Neutral feedback from joints, skin, muscles

• Allows quick reaction time and prevents injury

Kinesthesis

Conscious awareness of the position and movement of the body in space

• Walking downstairs without looking at each step

• Closing eyes and touching nose

4 Properties of Skeletal muscle tissue to produce force and movement of joints

Irritability or Excitability

Contractility

Extensibility

Elasticity

Irritability or Excitability

Property of muscle being sensitive or responsive to chemical, electrical, or mechanical stimuli

Contractility

Ability of muscle to contract and develop tension or internal force against resistance when stimulated

Extensibility

Ability of muscle to be stretched beyond its normal resting length without tissue damage

Elasticity

Ability of muscle to return to its original length following stretching or contraction

Tendon

Fibrous connective tissue that connects muscles to bones and other structures

• 2 muscles may share a common tendon (achilles tendon)

• A muscle may have multiple tendons connecting it to one or more bones (triceps brachii)

Origin

Structurally - Proximal attachment of a muscle or the part that attaches closest to the midline or center of the body

Functionally - Least moveable part or attachment of the muscle

Insertion pulled toward origin (typically)

Insertion

Structurally - Distal attachment or the part that attaches farthest from the midline or center of body

Functionally - Most moveable part is generally considered the insertion

Insertion → Origin

Isotonic Contractions

Involve muscle developing tension to either cause or control joint movement

Dynamic contractions

Contractions are either concentric or eccentric on basis of shortening/lengthening under tension

Concentric Contractions

Muscle fibers shorten throughout the range of motion to generate force to overcome the load and move the object

• Curl on the way up

Eccentric Contraction

Muscle fibers lengthen throughout the range of motion to control the load of the object, load overcomes contraction

• Curl on the way down

Isometric Contraction

Muscle fibers contract without movement, muscle is not shortened or lengthened, contraction and load are equal - fiber length is maintained

• Plank

Force Velocity Relationship

Velocity of a muscle contracting concentrically is inversely related to the amount of the force of applied

• Contraction occurs faster as load decreases

• Contraction occurs slower as load increases

In relation to concentric types

• Concentric: Load < Contraction

• Eccentric: Load > Contraction

• Isometric: Load = Contraction

Passive Movement

Movement at a given joint without any muscle contraction

• Due to external forces such as those applied by another person, resistance of force, or gravity in the presence of muscle relaxation

• Stretching

Action

Specific movement of joint resulting form concentric contraction of a muscle which crosses joint

• Biceps brachii has the action of flexion at elbow

• Multiple muscles have common action

• Actions are inherent to the muscle - based on location, size, and shape

Agonist Muscle

Muscles causing a certain joint motion through a specified plane of motion - know as prime movers

Dependent on the type of contraction and circumstances of the activity

Antagonist Muscles

When contracting concentrically perform the opposite joint motion of agonist

Usually located on the opposite side of the joint from the agonist

Work in cooperation with agonists by relaxing and allowing motion

• Must relax in order for prime mover to move

Synergist

Assist in action of agonist

Not necessarily prime movers

Know as guiding muscles

Assist in refined movement and rule out undesired motions

Force Couples

Occur when two or more forces are pulling in different directions on an object, causing the object to rotate about its axis

Coupling of muscular forces together in the body can result in a more efficient movement

Force-Tension Relationship

The force/tension that a muscle exerts varies with the length it is at when stimulated

The greatest force / tension is developed when there is optimal overlap between the actin and myosin fibers

Maximal tension is exerted when the muscle is at its resting length

100 - 130% of a muscles resting length is optimal

>130% decreases the amount of force muscle can exert

50 - 60 % of resting length = cannot contract effectively (too much overlap of myosin and actin)

What is force-tension relationship?

Muscles can produce movement most efficiently when the muscle fibers are at 100-130% of their resting length (optimal overlap)

Force-Tension Relationship Example

EX: 1 - Increasing ability to exert force

• Squat slightly to stretch the calf, hamstrings, and quadriceps before contracting same muscles concentrically to jump (slightly contracted - more force)

EX: 2 - Reducing ability to jump

• Isolate the gluteus maximus by maximally shortening the hamstrings with knee flexion (all the way down - less force)

Muscles are usually named due to . . .

Visual Appearance, Anatomical Location, Function

• Shape - deltoid, rhomboid

• Size - gluteus maximus, teres minor

• Number of Divisions - triceps brachii

• Direction of its Fibers - external oblique

• Location - rectus femoris, palmaris longus

• Point of Attachment - coracobrachialis, extensor hallucis longus

• Action - erector spinae, supinator, extensor digiti minimi

• Action & Size - adductor magnus

• Shape & Location - serratus anterior

• Location & Attachment - brachioradialis

• Location & Number of Divisions - biceps brachii

Parallel Muscles

Fibers arranged parallel to length of muscle

Produce a greater range of movement than smaller-sized muscles with pennate arrangement

Parallel Muscles Categorized as

• Flat - abdominal

• Fusiform - biceps brachii

• Strap - sartorius

• Radiate - pec. major

Pennate Muscles

Arranged obliquely to their tendons in a manner similar to a feather

Have shorter fibers

Arrangement increases the cross-sectional area of the muscle - increasing the power

More strength - not as broad as range of motion

Pennate Muscles Categorized as

• Unipennate - gastrocnemius

• Bipennate - rectus femoris

• Multipennate - deltoid

Fascia

Sheet or band of fibrous connective tissue that envelopes, separates, or binds together parts of the body such as muscles, organs, and other parts of the body

• In certain places around the body such as around joints like the wrist and ankle, fascial tissue forms a retinaculum (band-like) to retain/hold tendons close to the body

• EX: Foscia

Intrinsic

Pertaining usually to muscles within or belonging solely to the body part upon which they act

EX: small intrinsic muscles found entirely within the hand or feet

Extrinsic

Pertaining usually to muscles that arise or originate outside of (proximal to) body part upon which they act

EX: forearm muscles that attach proximally on distal humerus and insert on fingers

Uniarticular Muscles

Cross and act on one joint only

EX: brachialis

Biarticular Muscles

Cross and act on 2 different joints

EX: rectus femoris can act either one or both of its joints - maintain a relatively consistent length due to shortening at one joint and lengthening at another joint