Exam 1 - Biomechanics Flashcards
Kinesiology
Study of the science of movement
Musculoskeletal System
Bones, Ligaments, Joints, Muscles, Tendons
Sagitta Plane
- Bisects body into right and left halves
- also called anteroposterior or AP plane
- Motion in this plane is called flexion and extension
Frontal Plane
- Divides into front and back
- Also called the coronal plane
- Adduction and abduction movements
Transverse Plane
- Divides the body horizontally into superior and inferior halves
- Also called horizontal plane
- Rotational movements (pronation, supination, and spinal rotation)
Axes of Rotation
- Movement in one plane produces joint motion or axis of rotation
- Axis of rotation occurs 90 degrees from the plane that motion occurs
What is the axis of rotation of the Sagittal plane?
Lateral - Axis of Rotation
What is the axis of rotation of the Frontal plane?
Anteroposterior - Axis of Rotation
What is the axis of rotation of the Transverse plane?
Vertical - Axis of Rotation
Anterior
Front
Anteroinferior
Front & Below
Anterolateral
Front & Side
Anteromedial
Front & towards midline
Anteroposterior
- Front & Back
- X-ray taken with back against film plate and machine in front
Anterosuperior
Front & Top
Caudal
Away from head; lower
Cephalic
Relating the the head
Contralateral
Opposite sides of body
Deep
Internal
Distal
Away from center of body or from point of attachment
Dorsal
Relating to upper-side of back
Inferior
Below; away from head
Ipsilateral
Same side of body
Lateral
Toward side of body
Medial
Towards midline of body
Posterior
Back side of body
Posteroinferior
Back & lower - away from head
Posterolateral
Back & Side
Posteromedial
Back & towards midline
Posterosuperior
Back & upper; toward the head
Prone
Face down, palms up
Dorsal side up, ventral side down
Proximal
Closer to point of attachment
Superficial
External - closer to outside of body
Superior
Upper; towards head
Supine
Face up, palms down
Ventral
Front
Volar
Palm of hand & sole of foot
Long bones
- long cylindrical shaft
- wide protruding ends
- serve as levers
Short bones
- small, cube shaped, solid bones
- shock absorption
Flat bones
- curved surface
- can be thick or thin
- protection
Irregular bones
- variety of purposes
- include bones of spine, ischium, pubis, and maxilla
Sesamoid bones
- small bones embedded within the tendon of a musculoskeletal unity that provide protection
- called “free-floating” because they don’t attach to other bones
- improve mechanical advantage of musculotendinous unit
Joints
- Articulation of two or more bones
- classified by structure or function
- enable movement
Fibrous joints
- joined together by connective tissue
- immovable
- ex: sacroiliac joint, sternoclavicular
Cartilaginous joints
- Joined together by hyaline or fibrocartilage
- allows very slight movement
- ex: costochondral joints of the ribs, intervertebral discs
Synovial joints
- freely moveable
- contain a joint capsule
- contain synovial fluid
- generally, diarthrodial
Synarthrodial joints
- immovable
- ex: cranial sutures, socket of a tooth
Amphiarthrodial joints
- slightly moveable
3 types: - syndesmosis: joint held together by strong ligamentous structures
- symphysis: joint separated by fibrocartilage pad
- synchronosis: joint separated by hyaline cartilage
Diarthrodial joints
- freely moveable
- contain a joint capsule
- joint capsule surrounds the bony ends
- contain synovial fluid; lubricator the joint cavity
- ex: knee, shoulder
Motion in one plane
1 degree of freedom
Motion in two plane
Two degrees of freedom
Motion in three plane
3 degrees of freedom
Arthrodial (Gliding Joint)
- two flat, bony surfaces
- butt against each other
- permits limited gliding movement
- 1 degree of freedom
- ex: carpal bones of the wrist
Condylodial Joint
- also called biaxial ball and socket joints
- bones permit movement in two planes without rotation (2 degrees of freedom)
- ex: wrist between the radius and proximal row of the carpal bones
Enarthrodial Joint
Also called multiracial ball and socket joint
- permits movement in all three planes
- ex: hip and shoulder joints
Ginglymus Joint
- also called a hinge joint
- one plane of motion
- wide range of motion within that plane
- ex: elbow, knee
Sellar Joint
- also called a saddle Joint
- found only in the thumb
- permits ball and socket movement, except for rotation
Movement in Joints
- can be limited or wide-ranging
- some movements are relatively specific to a joint
- some movements describe motion at several joints
Abduction
Lateral movement away from midline of the body
Abduction
- Lateral movement away from midline of the body
- Frontal plane motion
Adduction
- Movement medically toward the midline of the trunk
- Front plane motion
Circumduction
- circular movement of a limb that delineates an arc
- combination of flexion, extension, abduction, and adduction
Flexion
- bending movement of a limb
- decrease in joint angle by moving bones together
- Sagittal plane
Extension
- straightening movement of a limb
- increase joint angle by moving bones apart
- Sagittal plane
External Rotation
- rotary movement around a longitudinal axis of a bone
- movement is away from the midline of the body
- transverse plane motion
Internal Rotation
- Rotary movement around the longitudinal axis of a bone
- movement is towards the midline of the body
- transverse plane motion
Muscles
- 600+ muscles
- 40-50% total BW
- responsible for movement of the body and joints
Muscle Terminology
–
Intrinsic muscles
- muscles within or belonging solely to the body part on which they act
- ex: small intrinsic muscles of the hand
Extrinsic muscles
- muscles that arise or originate outside of the body part on which they act
- ex: forearm muscles that attach to distal end of humerus and insert on the fingers
Action
- the specific movement of the joint resulting from a concentric (shortening) contraction of a muscle which crosses the Joint
- ex: the biceps brachii the action of flexion at the elbow
- action of a joint is caused by a group of muscles working together
- a particular muscle may cause more than one action either at the same joint or a different joint
Innvervation
- the segment of the nervous system defined as being responsible for providing a stimulus to muscle fibers within a specific muscle or portion of the muscle
- a particular muscle may be innervated by more than one nerve
- a particular nerve may innervate more than one muscle
Proximal Attachment/Insertion (ORIGIN)
- least moveable part
- part that attaches closes the midline/center of body
Distal Attachment/Insertion (Insertion)
- most moveable
- usually the part that attaches farthest from midline/center of the body
Types of Muscle Contraction
-
Isometric
- Tension is developed within the muscle, but the joint angle remains constant
- static contractions
Isotonic
- involve the muscle developing tension to either cause or control joint movement
- dynamic contraction: causes joint angle to change
Concentric
- muscle develop tension as it shortens
- occurs when muscle develops enough force to overcome applied resistance
- can be though of as causing movement against gravity or resistance
- POSITIVE CONTRACTION
- joint angle being changed in direction of applied muscular force
Eccentric
- involved the muscle lengthening under tension
- occurs when the muscle gradually lessens in tension to control the descent of the resistance
- control movement with gravity or resistance
- NEGATIVE CONTRACTIONS
- results in a change in the joint angle in the direction of the resistance or external force
Role of muscles
–
Agonist
- muscles that, when contracting concentrically, cause joint motion through a specified plane of motion
- prime movers
Antagonist
- muscles that are usually located on the opposite side of the joint from the agonist
- have opposite concentric action
- known as contralateral muscles
- work in cooperation with agonistic muscles by relaxing and allowing movement
Stabilizers
- muscles that surround the joint or body part
- contact to fixate or stabilize the area to enable another limb or body to exert force or move
- proximal stability leads to distal mobility
Synergist
- muscles that assist in action of agonists
- not necessarily the prime movers for the action
- guiding muscles
- assist in refining movement
