The Musculoskeletal System Flashcards
What are the General Joint Motions?
Flexion Extension Abduction Adduction Internal Rotation External Rotation
What does flexion do?
decreases the angle at a joint; rolls the body towards the fetal position
What does extension do?
increases the angle at a joint; roll the body away from the fetal position
What does internal rotation do?
move anterior surface towards the midline
What does the external rotation do?
move the anterior surface away from the midline
What are the Joint Specific Motions of the ankle?
Dorsiflexion and Plantar flexion
Inversion and Eversion
What does dorsiflexion do?
moves top of the foot towards the tibia; decrease angle between foot and leg
What does plantar flexion do?
moves the bottom downwards; increase the angle between leg and foot
What does inversion of the foot do?
bottom of the foot turns towards the midline
What does eversion of the foot do?
bottom of the foot turns away from the midline
What are the Joint Specific Motions of the hip and shoulders?
Horizontal Abduction and Horizontal Adduction
What does horizontal abduction motion do?
the segment is moved in the transverse plane, away from the midline
What does the horizontal adduction motion do?
the segment is moved in the transverse plane, towards the midline
What are the Joint Specific Motions of the Pelvis?
Posterior Pelvic Girdle Rotation Anterior Pelvic Girdle Rotation Left Lateral Pelvic Girdle Rotation Right Lateral Pelvic Girdle Rotation Right Transverse Pelvic Girdle Rotation Left Transverse Pelvic Girdle Rotation
Motions of the pelvis are defined by what?
ASIS (Anterior Superior Iliac Spine)
What does anterior pelvic girdle rotation move?
ASIS rotates forward in the sagittal plane; increases space
What does the posterior pelvic girdle rotation move?
ASIS rotates backward in the sagittal plane; decreasing space
What does the right lateral pelvic girdle rotation move?
right ASIS moves superiorly; conan dance
What does the left lateral pelvic girdle rotation move?
left ASIS moves superiorly; conan dance
What does the right transverse pelvic girdle rotation move?
right ASIS moves posteriorly; open hips when batting
What does the left transverse pelvic girdle rotation move?
left ASIS moves posteriorly; opens hips when batting
What are the Joint Specific Motions of the lumbar?
Right Lateral Lumbar Flexion
Left Lateral Lumbar Flexion
What does the right lateral lumbar flexion move?
upper body flexes to the right
What does the left lateral lumbar flexion move?
upper body flexes to the left
What does reduction do during a lateral lumbar motion?
brings the trunk back to midline; making the position anatomical neutral again
What is the name of the spine curvature on the cervical and lumbar regions?
loradodic
What is the name of the spine curvature on thoracic and sacral regions?
kyphosis
What are the Joint Specific Motions of the shoulder/scapula?
Upward Rotation Downward Rotation Protraction Retraction Elevation Depression
What does the upward rotation of the shoulder move?
the inferior angle moves superiorly and laterally; abduction
What does the downward rotation of the shoulder move?
the inferior angle moves inferiorly and medially; adduction
what does the protraction movement of the scapula move?
vertebral border of the scapula moves away from the midline; abduction
What does the retraction movement of the scapula move?
moves the scapula moves toward the midline; adduction
What does elevation do for the scapula?
scapula moves upward
What does the depression of the scapula do?
scapula moves down
What are the Joint Specific Movements of the Radio-Ulnar ?
Pronation
Supination
What is the pronation movement of the radio ulnar joint?
the thumb is positioned on the medial side of the elbow; palm down
What is the supination movement of the radio ulnar joint?
the thumb is positioned on the lateral side of the elbow; palm up
What are the Joint Specific Motions of the Wrist?
Radial and Ulnar Deviation
What is the radial deviation movement?
radial flexion; thumb moves toward the forearm
What is the ulnar deviation movement?
ulnar flexion; pinkie moves toward the forearm
What is the different layers of a muscle?
Muscle Fascicle Fiber Myofibril Myofilaments (myosin and actin)
Which bundle is non active?
Fascia; its like a rubber band, you have to pull it for a force to be produce
What does the epimysium surround?
the entire belly
What does the perimysium surround?
the entire fascicle
What does the endomysium surround?
the individual muscle fibers
What does the sarcolema surround?
the cytoplasm of muscle cell
What does the sarcomere surround?
muscle fibers
What is the active unit of myosin and actin?
sarcomere
What part of the sarcomere moves and what part stays still?
actin moves
myosin stays
Sliding Filament Theory
1) myosin crossbridge attaches to actin
2) cross bridge forms contraction
3) force is produced
4) actin and myosin slide past each other
5) sarcomere shortens
6) repeat
Where does the max force of a sarcomere occur?
2.0-2.25 micrometers
When does the actin move away from the center?
at 2.25-3.6 micrometers
When does force production drop?
under 1.65 micrometers
What are the different muscle actions?
concentric, eccentric, and isometric
What happens during a concentric action?
muscle force is greater than the resistant force; bench pressing normally
What happens during a eccentric action?
resistant force is greater than the muscle force; muscle length increases under tension
What happens during a isometric action?
total muscle length stays the same under tension
What is an isokinetic muscle action?
muscle action where the length of the muscle changes at the same speed throughout the ROM (same speed, variable resistance)
What is an isotonic muscle action?
tension of the muscle remains the same through the ROM (variable speed, same resistance)
What is an isoinertial muscle action?
external load remains the same throughout the entire ROM
What must a muscle produce to move a joint?
force
What happens to a joint when force is present?
it rotates
What causes a movement?
rotation at a joint
Tissue Properties of Muscle
Irritability
Contractibility
Distensibility
Elasticity
Stimulation by a chemical neurotransmitter causes what?
irritability
Ability to shorten, which is limited by joint ROM?
Contractibility
Ability to stretch or lengthen?
Distensibility
“distance”
Ability to return to normal state, after lengthening?
Elasticity
What develops force from a skeletal muscle?
active contractile
How is muscle force transmitted from a skeletal muscle?
tendon to bony insertion
What are the two types of skeletal muscle tissue?
muscle and connective
What contains active muscle force producing elements?
muscle tissue (contractile)
What connects contractile elements to a bone at the distal and proximal ends?
tendon
What separates muscle into compartments?
fascia
Hill’s Muscle Model
SEC-tendon
PEC-fascia
CC-sarcomere
What is the contractile component?
active shortening of muscles
What is Parallel Elastic Component?
parallel to the contractile element
CT in the surrounding muscle fibers
What is the Elastic Component?
resides in the cross bridges of actin and myosin and in the tendons
Explain the Stretch-Shortening Cycle?
rapid eccentric muscle action, followed by a concentric action
produces more force
-eccentric motion stores the energy like a rubber band
-works only if action is spontaneously after one another.
Purposes of the Skeletal System?
- protect
- facilitate movements; levers
- provide attachment sites for muscles
- production of RBC
What are the Structural Components of Bones?
- second to dentin/enamel as the hardest part of the body
- metabolically active throughout life
- high vascular
- adaptive to mechanical demands
- Ca and P makes it hard
- collagen fibers allow for pliability
- allows for stability and mobility
What is viscoelasticity?
is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation
What are the 2 Skeletal Systems?
Axial
Appendicular
What bones make up the Axial Skeleton?
“central pillar”
skull
spine
thorax
What bones make up Appendicular Skeleton?
upper and lower extremities
Different Mechanical Loading of Bones?
Compression Tension Shear Torsion Bending (look at slide 50)
Where is the bone the strongest?
along the long axis
What does anisotropy mean?
stronger in certain directions
Where is the cortical bone found?
found in outer shell along the shaft
What bone is better at absorbing bone?
cancellous bone
What does tension do to the bone?
the long axis is loaded and it pulls the bone in opposite directions
What does compression do to the bone?
the long axis is loaded and the bone pushes towards the center
What does Bending do to the bone?
tension on the longer side and compression on the smaller side
What does Shear do to the bone?
force in opposite direction across long axis; causes a break on the backside of the bone
What does Torsion do to the bone?
force causes a rotation force along the long axis; “spiral fracture”
Bone is strongest where?
in compression
Bone is weaker in what?
tension
Bone is weakest in what?
shear