Upgrade to remove ads
Spinal Biomechanics - FINAL
Terms in this set (58)
When joint structures fail due to lack of adequate recovery time between loads, even though the loads may be within normal loading ranges, it is referred to as a(n) ____________________ injury.
The most predominant coupled motions occurring in the vertebral column involve ___________ and ___________.
The typical adult vertebral column contains _____ inter-vertebral discs.
The amount of motion available in an area of the vertebral column is determined by the relative height of the _______ as compared to the vertebral body height.
Vertebral intersegmental motion, with some exceptions, is essentially limited by the _______________.
In humans, development of the lumbar lordosis is generally completed by the age of ______ year(s).
The direction of motion allowed in the vertebral column is generally determined by the ___________.
Facet capsules tend to be thickest at the ____________.
C/T and T/L junctions
Using engineering principles, we can calculate that the cervical, thoracic and lumbar curves of the spine increase its resistance to axial compressive forces by ______ times.
During rotation and lateral flexion of the head and neck, the upper cervical segments _____________ the lower cervical segments.
_______: The application of mechanical laws to living structures, specifically to the locomotor system of the human body.
________ The branch of mechanics that deals with the geometry of the motion of objects, including displacement, velocity, & acceleration, without taking into account the forces that produce the motion
_______: The study of the relationships between the force system acting on a body and the changes it produces in body motion.
_______ (A to P): Vertical plane that divides the body from anterior to posterior (flexion-extension motions)
______ (Frontal): Vertical plane that divides the body from side to side (lateral or side to side motions; abduction/adduction)
________: Horizontal plane that divides the body into upper and lower components (rotational motions; axial rotation)
_______ (coronal): Runs side to side (flexion-extension)
______ (vertical): Runs up and down (rotation)
______ (anteroposterior): Runs front to back (lateral bending)
_______ considers the physics of movement of a body in space.
Mass = weight (on earth)
Mass = 1/6 weight (on the moon)
Mass = 0 (in space)
Center of mass (CoM) is a theoretical construct that is defined as a point about which the bodies mass is equally distributed.
Center of Mass (CoM) = Center of Gravity (CoG)
Location of CoM is variable
Depends on body position (lowering the CoM above the base of support increases stability)
i.e. punching bag toy, palm tree
Punching bag with Center of Mass close to base
Base of Support (BoS) The area which supports the mass above
_________ (linear displacement): Each point on a segment moves in a straight line through the same distance, at the same time, through parallel paths. (push or pull a glass of water)
______ (angular displacement): Each point on a segment moves in a curved path around a fixed axis through the same angle, at the same time, at a constant distance from the axis. (lift water glass at elbow)
________: all points on the object movie the same distance.
________: all points move around a central fixed center of rotation
_______ - the law of inertia; an object will remain at rest or in uniform motion unless acted on by an unbalanced force.
_________- remains motionless when acted on by forces.
_________ - remains in constant motion when acted on by forces (rare in the human body)
__________ - the law of acceleration; the acceleration of an object is proportional to the net forces acting on it and inversely proportional to its mass.
i.e., the greater the mass of an object the more force it takes to move it.
__________- the law of reaction; for every action there is an equal and opposite reaction.
____________ - two or more forces act on the same object, in the same plane, and in the same line. Lines of force run parallel to each other. Forces that move superior (along the y axis), to the right (along the x axis) and anterior (along the z axis) are considered positive (+); forces to the opposite directions are negative (-).
* Not very common in the human body!
Linear force system
_____________ - the lines of force are at angles to each other and converge at some point either internal or external to the object. Any two forces in a concurrent system can be composed into a single
resultant force (vector)
* Most common in the human body!
Concurrent force system
Tissue Slack & Line of Drive
In manual therapies, i.e. chiropractic, when we prepare to assess or manipulate a joint of the body we address tissue slack & line of drive. These are generally verbalized in individual vectors (lines of force) but are actuated using the combined resultant vector.
Example: The tissue slack & line of drive for a particular thoracic adjustment may be verbalized as Inferior to Superior (I to S), Medial to Lateral (M to L), and Posterior to Anterior (P to A), but the actual procedure is performed using the resultant vector.
aka: I to S, M to L & P to A
___________ - a net force that moves an object (bony segment) away from an adjacent object (bony segment).
____________ - forces that create opposite pulls on an object; opposite forces are necessary to create tension. (ligaments and joint capsules)
Tension around a 'pulley'
____________ - the result of gravity on an object.
____________ - reaction forces resulting from the push of one object against another; aka joint reaction forces when it involves two contiguous joint surfaces
__________ - two forces that cause joint reaction forces.
FORCE = mass X acceleration
(F = m x a)
Close Packed Position aka: close packing a joint
The rotation of one segment of a joint relative to the adjacent segment (twisting), drawing the adjacent articular surfaces into contact (compression). This is caused by creating tension in the capsuloligamentous structures.
________ - any forces that are parallel to contacting surfaces, attempting to move one object on another.
________ - potentially exist whenever there is contact force & is opposite the direction of shear forces. Must have a shear force to produce a friction force.
__________ - the strength of rotation produced in an object when an isolated force does not pass through the Center of Mass. A combination of rotatory & translatory motion.
_________ - two or more forces applied to the same object are parallel to each other.
Parallel Force Systems
_________ - occurs when torque forces produce a rotation of a segment around its long axis. Most muscles produce torques/moments around two or more axes because they attach at the periphery of the bones.
*_____ ______ create a "twisting" motion between two objects, i.e. joints.
_____________ - the resultant vector of the concurrent force system produced by the fibers of a muscle contracting. The vector is from the point of application or muscle attachment and parallel to the muscle fibers and tendon. The direction of pull is always towards the center of the muscle.
*Every muscle pulls on each of its attachments every time it exerts a force.
Total Muscle Force Vector
________ - bones or bony prominences that alter the direction of pull of a muscle. They deflect the action line of a muscle away from the joint axis, thus increasing the Moment Arm (MA) and torque produced by a muscle force.
_________ lever - the axis lies between the effort force and the resistance force.
First class lever
Example - rare in the human body; the supraspinatus muscle acts on the humerus proximal to the axis of rotation and the Center of Mass is just above the elbow. This is a 1st class system whether the supraspinatus is the EF or RF.
___________ - the resistance force lies between the axis and the effort force.
Example - occurs when gravity is the EF and the muscle is the RF, producing active lengthening of the muscle (eccentric contraction), i.e., lowering the leg slowly against gravity (deceleration).
Second class lever
_______ - the effort force lies between the axis and the resistance force.
Example - a muscle creating joint rotation in its direction of pull, i.e., the quadraceps muscle (EF) extending the knee against gravity (RF).
Third class lever
For second or third class lever systems in the human body, the classification is dependant on whether the muscle is the EF (3rd class) or the RF (2nd class)
When muscle is EF = ______
When muscle is RF = _______
When EF = RF (no net torque) = _______
YOU MIGHT ALSO LIKE...
Spinal biomechanics Exam 1
KIN 3514 Final pt. 1
kines 137 exam 1 (first half)
OTHER SETS BY THIS CREATOR
CH -Study guide - Tri 7
Biochem RIBS practice questions
CR Phys RIBS ICE1 D