Slide 8 - Muscular Strength Flashcards
Muscular strength is
Activities are
The ability of a muscle to exert a maximum contractile force against a resistance
Short in duration and high/max intensity
Muscular endurance is
Activities are
Ability of a muscle to exert submaximal force repeatedly over time
Long duration but low intensity
What purpose does strength testing have
Determine importance of strength and power to performance
Develop an athletes profile
Monitor training progress
Monitor injury rehabilitation
What are the types of muscular contraction
Static = isometric
Dynamic = isotonic
What is isometric
Muscle contractions produce little or no movement as in pushing or pulling against an immovable object
What is isotonic
Muscle contractions produce movement = lengthening and shortening
What are the different action phases
Concentric
Eccentric
What is concentric
Shortening
Positive resistance
Over come gravity
What is Eccentric
What type of movements
What are they more effective in
Lengthening
Negative resistance
Resist gravity
Controlled movements
Producing muscle hypertrophy but result in greater muscle soreness
Isotonic force production:
Strength:
Work:
Power:
Maximal force measured at any velocity
Force (or torque) substained over a distance
Work (J) = Force (N) x distance(m)
Work performed per unit of time
Power (w) = work(J)/time(s)
What is the equation for work
Work = force x distance
What is the equation for power
Power = work / time
What is Isokinetic
Maximal contraction at a constant speed throughout ROM
Accommodating resistance
Isokinetic dynamometry focused on
Happened in
Measure strength and power under a range of conditions
Angular velocity Positioning Range of motion Contraction mode Movement sequence
Happened in the late 1960s
What are the different assessments of muscular strength and endurance
Handgrip test
Upper and lower body 1 RM prediction
Isokinetic test
What does the Handgrip test measure
What is it useful for
Static and maximal contraction
Useful index of overall musculoskeletal condition due to its functional importance in everyday tasks
What are the two protocols for handgrip
Protocol 1: ACSM
Elbow at any angle between 90 and 180 degrees
Protocol 2: CSEP
Shoulder slightly abducted with arm straight
What is the problem with 1 RM prediction test
Some people are not comfortable doing it
What does 1 RM prediction utilise
A muscular endurance test to estimate muscular strength
What equation is used for 1 RM prediction
What is it
Brzycki equation
Weight lifted (lbs
____________________
1.0278 - ((reps to fatigue) * 0.0278))
Isokinetic test involves
22 isolated joint movement patterns
4 resistance modes
Balance attachment
Work simulation
Integrated EMG
Where are the 22 isolated joint movement patterns
Shoulder Elbow Wrist Hip Knee Ankle Back
What are the 4 resistance modes
Passive
Isometric
Isokinetic
Isotonic
What are the steps for isokinetic testing
General cardio warm up
Enter client information
Position client
Select pattern
Set protocol
Pre speed warm up
Test - push and pull as hard and fast as possible
The knee flexion and extension in the isokinetic test involves
Seat position
Arms across chest
Recommended 80 degree hip flexion
Align dynamometer rotational axis with lateral epicondyle of femur
Restrait staps on distal thigh, pelvis and upper torso
Bottom of shin pad just above lateral malleolus
What does iskinetic test measure
Peak Torque
Angle specific torque
Average torque
Work
Power
Endurance
What comes under Peak torque
What is it expressed in
Angular force
Expressed in Newton meters
What comes under angle specific torque
Torque at a specific angle in the ROM
What comes under average torque
Whole torque curve
What comes under work
Torque sustained over a distance
What comes under power
Rate at which work is done
What comes under endurance
% decreaase in peak torque and number of reps completed before 50% fatigue
What are the intra individual comparisons in the test
Bilateral comparison - right vs left
10-15% difference in lower limbs in uninjured athletes
What are the Reciprocal comparisons in the test
Agonist vs antagonist
Eccentric vs concentric
What are the inter individual comparisons in the test
Absolute values or relative to body mass
What is the Equipment variability within the test
Results may vary between dynamometers (5-20% difference sometimes)
Test positions
Body stabilisation
Operating characteristics
Data processing
What is the client variability within the test
Pretest status - test strength before endurance or cardio
Ergogenic aids - caffeine, bicarbonate, creatine
Time of day - diurnal rhythms may affect result up to 10%
Muscular endurance is defined as the ability of a muscle to exert a maximum contractile fore against a resistance
False
_______ contraction is a type of isotonic contraction of the muscle where muscles changes its length and overcome the gravity
Concentric
The amount of work that muscles generate can be calculated from the amount of force that muscle exerted over a distance
True
1 repetition maximum (1RM) is considered as a gold standard to assess the muscular strength
True
Static muscle contractions produce little or no movement as in pushing or pulling against an immovable object
True
When we perform isokinetic assessment (using Humac Norm) in the lab, inter-individual comparisons can be made by comparing work of agonist and antagonist muscles
False
When we perform isokinetic assessment (using Humac Norm) in the lab, ____________ comparisons can be made by comparing eccentric and concentric contractions that muscles generate
Reciprocal
The results of handgrip muscular strength can vary if you test the subject in the morning vs. in the afternoon
True
The amount of power the muscles performed can be measured by the force that muscle generated and the distance that moved
False
Muscular endurance is the ability to lift weight in a single maximal effort
False
The main difference in CSEP and regular (ACSM) handgrip strength test protocol is the position of the arms
True
The arm position for CSEP handgrip strength test protocol is with slight abduction of shoulder and straight arms
True
Brzyci method is used to assess muscular strength in our lab; this method predicts 1-RM by performing repetitive muscular contractions less than 5 and more than 10
False
During weight lifting exercise, you lifted 20 kilogram weight upward and downward over the distance of 2 meters. How much of work did you perform
(20 x 9.81) x 4m
(m x g) x d
784.8J
During cycling exercise, you performed a total work output of 20,000 J for 2 minutes. What is your power output
20,000/120s
166.7 watts
