Neurological Considerations for Movement Flashcards

Question

Types of Intrafusal Fibers

Answer 1

- Nucleat Bag Fibers - Nuclear Chain Fibers

Answer 2

Intrafusal fibers with a **large clustering of nuclei in the center ** **Type Ia afferent** neurons exit from middle portion of the fiber (primary afferent) - Respond to stretch by initiating stretch reflex, **velocity dependent** (must be quick; done quickly results in contraction); **Protective; Contraction**

Answer 3

Intrafusal fiber with nuclei arranged in rows Both Type Ia & II sensory neurons exit from this fiber (primary and secondary afferent) Type 1a: Respond to stretch by initiating stretch reflex; Quick stretch; quick then done; Protective; Contraction - Ex: Stretch Reflex Type 2: Feedback does not diminish with time (not velocity dependent), can cause **relaxation in muscle being stretched; Does NOT diminish with time; NOT Velocity dependent ** - Slow and sustained - Ex: Therapeutic Stretching (Chronic change in length through stretch)

Answer 4

Gamma motor neuron: Innervates contractile ends of muscle spindle Gamma bias: Readjustment of muscle spindle length by contracting ends of intrafusal fiber Gamma Loop: Reflex arc that works with stretch reflex - Includes afferent, gamma, and alpha pathways This can change the threshold needed (the length change) for this type of reflexive behavior

Answer 5

Facilitates muscle contraction (via muscle spindle) of a muscle being stretched During this activation the antagonists relax allowing agonists to produce joint motion (Reciprocal inhibition)

Answer 6

Autogenic facilitation = 25-30% of force output Elastic Energy = 70-75% of force output **Big driver here!!!!! **

Answer 7

**Monitors Muscle Tension (Active Tension)** Extrafusal fibers - Fibers outside of muscle spindle Inverse stretch reflex - Initiated by high tension in muscle - Inhibits contraction of muscle via GTO - Causes relaxation of a vigorously contracting muscle (Protective) During treatment with a patient must train the muscles to inhibit the reaction from GTO that is trying to relax the muscle after a surgery or injury

Answer 8

Countermovement, quick, use elastic energy = more maximal effort Trying to get 1a afferent response

Answer 9

Perform movement slower, don’t use elastic energy, don't use stretch reflex = precise movement

Answer 10

Sensors monitor Joints Respond to pain, "Swelling" Ruffini ending - Sensory receptor in joint capsule that response to change in joint position Pacinian corpuscle - Sensory receptor in skin stimulated by pressure Reason we don't like swelling - Edema effects ability to move and sensation - Very small amounts have large effects

Answer 11

Joint position sense or threshold to detect motion Involves supraspinal processing of input from peripheral receptors

Answer 12

Less Active receptors effects joint position with increase in errors

Answer 13

Neural adaptations during the first 4 weeks of training Strength increases significantly due to neural adaptation significantly increasing Teach how to use muscles and limit GTO - Hypertrophy occurs much later past 4-6 weeks

Answer 14

- Significant gains within 4 weeks of training (Due to neuro) - Neural adaptations to training (Reduction in inhibition - GTO; Increased neural facilitation and synchronization - Bilateral deficit (Loss of both force and neural output through bilateral training; Train one limb at a time leads to greater force output but doesn't transfer to specificity) - Overall decision to train asymmetrically or bilaterally should follow the specificity principle (Ex: Football - Bilateral; Tennis - Unilateral) - Cross Education - train opposite limb to get less fatigue on untrained limb; Upper body better than lower body - Patterns of limb movements (Flexors/Extensors) - Warm up (5-10 min; increases motor unit activity) - Opposing muscle groups in sequence (Neural Benefits) - Immobilization (Decreases motor unit activity) - Inflammation (Decreases muscle acitivation and muscle strength) - Plyometric exercises (Uses "autogenic facilitation" (25-30% of force output) and elastic energy (70-75% of force output) )

Answer 15

Static (slow sustained stretch) vs ballistic stretching Static: - Minimize muscle spindle activation – Type 1a afferents - Stimulation of Type 2 afferents of muscle spindle – relaxation - Extreme stretch – GTO (inverse stretch reflex); Not as much data supporting this Warm + Stretching - Improve plasticity of tissues

Answer 16

Largest effect >60s Very inflexible: 6-10 minutes?? Put weight on knee for long period of time

Answer 17

Contract – Relax (PNF – proprioceptive neuromuscular facilitation) Used to stimulate relaxation "Tricks" muscle spindles (Type 1a) Pushing and talk back through ROM or keep him at end ROM then bring back relax and push further

Answer 18

Muscle responsible for a specific motion Prime vs assistant - Elbow flexion (Biceps-prime, brachialis-assitant) Muscles can have additional roles - Shoulder flexion (Anterior deltoid-prime, biceps-assitant)

Answer 19

Oppose action of the agonist Elbow flexion Biceps – agonist Triceps – Antagonist

Answer 20

Allows for movement of one muscle group to move (Ex: Quads) by inhibition of hamstrings

Answer 21

Cerebral Palsy (Wasteful metabolically) E-stim

Answer 22

Cooperative role of two or more muscles to procuce the same action

Answer 23

muscles with a common action in one place, opposing action in other planes Ulnar flexion (wrist) - Flexor carpi ulnaris/Extensor carpi unlaris - If one is damaged leads to favor it the direction of good muscle Lateral flexion (trunk) - Obliques

Answer 24

Requires a multi-articular muscle and a muscle that opposes this action at one or more joints (but not all joints) **One muscle stabilizes, one acts** Making a fist Wrist flexors/extensors Hamstrings: knee flexion without hip extension Requires hip flexors

Answer 25

Logic or Palpation EMG Ultrasound

Answer 26

Insertions of muscle Joints crossed Movement (planes/axes)

Answer 27

- Neural - Measures voltage differences between two sites (Idea of recruitment when performing an activity) - Summation of all motor units activation - Electrodes on/in muscle to determine motor unit activity (How much impulses are going to muscle) - Fast twitch will be much higher than slow twitch - How many muscle fibers we have firing - Tells us the sequence of muscle activity - Amount of tension??? (None! **Only tension under isometric positions. **)

Answer 28

Emerging method! Can measure cross sectional area change