Lecture 4 - Strength Flashcards
List the 5 Factors that affect strength
- number of fibres activated
- tension of each fibre/stretch
- biomechanical status or muscle & levers
- neural control (rate coding, number of fibres activated)
- rate of muscle contraction
What are the functions of muscle tissue?
- producing body movements
- maintaining posture/stabilizing joint
- generating heat
- storing & moving substances within the body
list the order of muscle organization
- muscle
- muscle fascicles
- muscle fibre (muscle cell)
- myofibril
- sarcomere
What is the Sliding Filament Model (theory)
- Thin filaments slide past the thick ones so that the actin and myosin filaments overlap to a greater degree
- In the relaxed state, thin and thick filaments overlap only slightly
- Upon stimulation, myosin heads bind to actin and sliding begins
Describe the Muscle Rate Coding
- A single stimulus results in a single contractile response – a muscle twitch
- Frequently delivered stimuli (muscle does not have time to completely relax) increases contractile force – wave summation
- More stimuli are delivered more rapidly, progressing to a sustained but quivering contraction referred to as unfused or incomplete tetanus
- Stimulation frequency increases more and muscle tension increases until a maximal tension is reached, the sustained contraction plateau is called fused or complete tetanus
explain muscle recruitment
Threshold stimulus – the stimulus strength at which the first observable muscle contraction occurs
Brain recruits smaller, lower threshold motor units first
As force needs increase, larger higher threshold motor units are recruited
This phenomenon, called motor recruitment, brings more and more muscle fibers into play to create a forceful contraction
Greater the muscle ______, greater the ability to produce ______
Greater the muscle CROSS SECTIONAL AREA, greater ability to produce FORCE
What is the order of muscle recruitment?
- Planning, initiation and movement timing blueprints are in the cerebellum and basal ganglia
- Commands are sent to the motor cortex
- The motor cortex sends the command down the spinal cord to motor neurons
- Motor neurons travel from the spinal cord to the muscle
- Muscle activation
- Sensory feedback on movement success
- Correction of planning errors
- Back to number 1
Centre of gravity for males and females is usually at…..
Females : S1/S2
Males : L4/L5
What must be looked at when conducting a Needs Analysis?
- Goals of the Client
- Hx of injuries
- Clients physical ability
- Time allocated for workouts
- Equipment Available
What is a Traditional Beginner Program?
- 48 hrs rest btwn each muscle group workout
- 2-3 days / week
- often full-body workouts
What is a Traditional Intermediate Program?
-Split routines (i.e. upper body 1 day, lower body the next)
What would a program for athletes & advanced training be structured like?
5-6 days per week, with 2-a-days
How is muscle strength increased or decreased?
- muscle imbalances
- mechanics
- mobility or muscle tightness
- firing pattern
- positioning & biomechanics
