Exam #1 (ch. 1-4) Flashcards
-describes the MOTION of a body without regard to the forces or torques that may have produced the motion. Ex: walking velocity and angular displacement (ROM) of a joint.
Kinematics:
-describes the FORCES (or torques) that act on or within a body. Examples include compression of an article disc tension within a stretched ligament.
Kinetics:
Is it translation (rectilinear or curvilinear); rotation or both;
-walking
-ice skating
-cartwheel
-baseball throw
Walking: Curvilinear, joints: rotation
Ice skating: Rectinilear
Cartwheel: Curvilinear. joints: rotation
Baseball: Curvilinear of COG, rotation at multiple joints, the ball rotates and translates
Passive accessory motions at the ,metacarpophalangeal joint are greater ___________
in or near full extension
Which of the following is more stable: open-packed, close-packed
Closed-packed
What position is more closed-packed for the metacarpophalangeal joint?
near full flexion
At the index finger, the closed-packed position is associated with elongation and increased tension in the joint collateral ligaments. True or False?
True
What is the difference between force and torque?
-Force: a push or pull against a mass
-Torque: rotator equivalent of a force, its magnitude = to the product of a muscle force and moment arm.
Describe a particular aspect of a muscle’s contraction relative to a joint force using the term: force
Contraction force produced by the elbow flexor muscles can create significant compression with the elbow joint
Describe a particular aspect of a muscle’s contraction relative to a joint force using the term: torque
Torque produced by the elbow flexor can produce a rapid angular acceleration of the elbow, quickly bringing the hand to the mouth.
-a torque produced around a joint by an internal force such as muscle contraction.
Internal torque:
- a torque produced around a joint caused by an external force (such as gravity or manual resistance)
external torque:
-opposing internal and external torques about a joint (within a given plane) are equal, the joint is often in___________
static equilibrium:
Explain how changing the speed at which you lower a book to a table can affect the type of activation (e.g., eccentric and concentric) and choice of muscles.
-gravity is acting on the book and eccentric activation (“braking”) of the elbow flexors muscles. Elbow flexors control the movement by decelerating the descent of the book
-to accelerate the book at the rate that exceeds the pull of gravity, the elbow extensors must contract (concentric) to produce rapid descent of the book.
- Difference between force & pressure?
- How could these differences apply to protecting the skin of a patient with a spinal cord injury and reduced sensation?
- Give an example:
- -force is the magnitude of a push applied against the patient’s skin. Pressure is the force divided by the contact area.
-a force applied to a small surface area can create large and potentially damaging pressure (also called stress). - A person with a spinal cord injury often has impaired sensation and is not able to perceive a potentially damaging level of contact pressure. To reduce the pressure it is important to maximize the contact area between the skin and external object.
- A proper fitting wheelchair with a proper seat cushion maximizes the surface area that contacts the ischial region. reduce wrinkles in clothing
-describes the number of particles that exist in an object.
Mass:
-is a force that describes gravitational pull exerted on a mass
weight:
Describe the difference between mass and weight.
A person’s mass is known by dividing the person’s body weight (in newtons) by the acceleration caused by gravity 9.81 m/sec2)
-number of independent directions of movement allowed at a joint or the number of permitted
Planes of angular motion:
What are the 3 degrees of angular freedom for the shoulder, wrist, and elbow and their corresponding planes?
Shoulder = 3, Frontal, Sagittal, Transverse
Wrist = 2, Frontal, Sagittal
Elbow = 1, Sagittal
What is the axis of motion for the sagittal, frontal, and transverse planes?
Sagittal: M-L
Frontal: A-P
Transverse: Longitudinal
a device that can measure and report the specific gravity and angular rate of an object to which it is attached.
Inertial measurement unit: IMU
-provides a measure of angular rate
gyroscope:
-provide a measure specific force/acceleration
accelerometer:
An accelerometer and gyroscope consists of __________ unit.
Inertial measurement unit (IMU)
-experimental technique recording and analysis of myoelectric signals. Myoelectric signals are formed by physiological variations in the state of muscle fiber membranes
Electromyography (EMG):
-the study of muscle function through inquiry of electrical signals the muscles emanate
EMG
-the study of neuromuscular activation of muscles within postural tasks, functional movements, work conditions, and treatment/training regimes.
Kinesiological EMG:
-consist of a single (alpha) motor neuron and all its innervated muscle fibers.
Motor Unit:
-joints w/slight to no motion based on the type of particular tissue
Synarthoses:
-joints that allows moderate to extensive motion
Diarthroses:
-dense connective tissues with high collagen levels: skill distal tib-fib (syndesmosis)
Fibrous:
-stabilized by flexible fibrocartilage/hyaline cartilage; function to strongly bind/transfer forces.
Cartilaginous:
What 7 elements are always associated with synovial joints or diarthrodial joints?
- Articular cartilage
- Blood vessels
- Ligaments
- Synovial membrane
- Sensory nerves
- Capsular ligaments
- Joint capsule
-describes the path of an axis of rotation about a joint, throughout a full range of motion.
Evolute:
-describes the specific location of an axis of rotation at a distinct point (instant) in a joints ROM
Instantaneous axis of rotation (IAR):
What are the 4 primary types of tissue found in the body:
Connective tissue: forms basic joint structures
Muscles: contractile (skeletal, cardiac, smooth)
Nerve
Epithelium
-specialized connective tissue
-highly cross-linked type I collagen
-cells (osteoblasts/osteoclasts/osteocytes)
bone:
-specialized connective tissue
-highly cross-linked type I collagen
-cells (osteoblasts/osteoclasts/osteocytes)
bone:
-tension and compression cycles create a small electrical potential that stimulates bone decomposition and increases density at points of stress
Wolff’s Law:
-marked changes in structure and function of its connective tissue- loss of mass, volume, strength
-happens with days but recovery so; full recovery is often incomplete
Immbolization:
-accompanied by a slowing of the rate of fibrous proteins and proteoglycan replacement and repair in all particular tissues and bone
-loss of ability to restrain and disperse forces - microtrauma
Aging impact on periarticular connective tissue and bone:
What are the 5 elements that are sometimes associated with synovial or diarthrodial joints?
- Intra-articular discs or menisci
- Peripheral labrum
- Fat pads
- Bursa
- Synovial pilca
What are the 6 particular connective tissues:
- Capsule
- Ligament
- Tendon
- Articular cartilage
- Fibrocartilage
- Bone
Collagen and Elastin fibroud proteins in all periarticualr connective tissues/characteristics. True or False?
True
-collagen fibers extending deep into the bone
Sharpery fibers:
How does cartilage receive its nutrients:
-via synovial fluid
-“milking action”
-intermittent joint loading
GaG’s are proteoglycan compounds. Due to this what allows them to give physical resilience?
-stiffness and hydrophilic nature of the sugar chains help the PGs protect cells from outside forces.
-the ability to sense the static or dynamic position of a limb
Joint proprioception
-embedded in the skin, muscles periarticular connective tissues
Sensory fibers:
-afferent joint receptors
Mechanoreceptors:
: a thin layer of connective tissue that surrounds individual muscles cell/fibers.
Endomysium
- the sheath of connective tissue surrounding a bundle of muscle fibers (facile)
Perimysium:
- the sheath of connective tissue surrounding a bundle of muscle fibers (facile)
Perimysium:
- a sheath of fibrous elastic tissue surrounding a muscle belly
Epimysium
What are the 2 contractile active proteins?
actin and myosin
-fibers run parallel to one another and a central tension
-designed for mobility, low force over a long range
Fusiform
-Contain a larger # of fibers per area
-Generate relatively larger forces
-Most muscles groups
Pennate:
- the ultimate force generator in the muscle?
Sarcomere:
Do the active proteins themselves shorten?
NO!, each myosin head is attached to an adjacent actin filament- forming a cross-bridge
-the discharged rate of sequential action potential
rate coding:
______ and _____ of the motor unit act in the rose of muscle force and are highly specific demand
Rate code and recruitment
An increasing number of sarcomeres in _______ is associated with skeletal muscle hypertrophy and increased contractile force.
parallel
An increase in the number of sarcomere in _______ is associated with an increase in the speed and contraction of the muscle fiber.
series
What are the 3 types of muscles fibers:
- Fast Glycolytic (FG)
- Fast Oxidative Glycolytic (FOG)
- Slow Oxidative (SO)
-it is the point from which its weight force acts
-evenly distributed in all directions
-can be outside the body
Center of Mass (COM)
